diff --git a/README.md b/README.md
index f30fd30a..c5522793 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Internet Archive Search Service
 
-A service for searching and retrieving metadata from the Internet Archive.
+A service for searching the Internet Archive.
 
 ## Installation
 ```bash
@@ -13,6 +13,7 @@ npm install @internetarchive/search-service
 ```ts
 import {
   SearchService,
+  SearchType,
   SortParam,
   SortDirection
 } from '@internetarchive/search-service';
@@ -23,50 +24,118 @@ const params = {
   query: 'collection:books AND title:(goody)',
   sort: [dateSort],
   rows: 25,
-  start: 0,
   fields: ['identifier', 'collection', 'title', 'creator']
 };
 
-const result = await searchService.performSearch(params);
+const result = await searchService.search(params, SearchType.METADATA);
 if (result.success) {
   const searchResponse = result.success;
-  searchResponse.response.numFound // => number
-  searchResponse.response.docs // => Metadata[] array
-  searchResponse.response.docs[0].identifier // => 'identifier-foo'
+  searchResponse.response.totalResults // => number -- total number of search results available to fetch
+  searchResponse.response.returnedCount // => number -- how many search results are included in this response
+  searchResponse.response.results // => Result[] array
+  searchResponse.response.results[0].identifier // => 'some-item-identifier'
+  searchResponse.response.results[0].title?.value // => 'some-item-title', or possibly undefined if no title exists on the item
 }
 ```
 
-### Fetch Metadata
+Currently available search types are `SearchType.METADATA` and `SearchType.FULLTEXT`.
 
-```ts
-const metadataResponse: MetadataResponse = await searchService.fetchMetadata('some-identifier');
+### Search parameters
 
-metadataResponse.metadata.identifier // => 'some-identifier'
-metadataResponse.metadata.collection.value // => 'some-collection'
-metadataResponse.metadata.collection.values // => ['some-collection', 'another-collection', 'more-collections']
-```
+The `params` object passed as first argument to search calls can have the following properties:
 
-## Metadata Values
+#### `query`
+The full search query, which may include Lucene syntax.
 
-Internet Archive Metadata is expansive and nearly all metadata fields can be returned as either an array, string, or number.
+#### `rows`
+The maximum number of search results to be retrieved per page.
 
-The Search Service handles all of the possible variations in data formats and converts them to their appropriate types. For instance on date fields, like `date`, it takes the string returned and converts it into a native javascript `Date` value. Similarly for duration-type fields, like `length`, it takes the duration, which can be seconds `324.34` or `hh:mm:ss.ms` and converts them to a `number` in seconds.
+#### `page`
+Which page of results to retrieve, beginning from page 1.
+Each page is sized according to the `rows` parameter, so requesting `{ rows: 20, page: 3 }`
+would retrieve results 41-60, etc.
 
-There are parsers for several different field types, like `Number`, `String`, `Date`, and `Duration` and others can be added for other field types.
+#### `fields`
+An array of metadata field names that should be present on the returned search results.
 
-See `src/models/metadata-fields/field-types.ts`
+#### `sort`
+An array of sorting parameters to apply to the results.
+The first array element specifies the primary sort, the second element the secondary sort, and so on.
+Each sorting parameter has the form 
+```js
+{ field: string, direction: 'asc' | 'desc' }
+```
+where `field` is the name of the column to sort on (e.g., title) and `direction` is whether to sort ascending or descending.
+
+#### `aggregations`
+An object specifying which aggregations to retrieve with the query.
+To retrieve no aggregations at all, this object should be `{ omit: true }`.
+To retrieve aggregations for one or more keys, this object should resemble 
+```js
+{ simpleParams: ['subject', 'creator', /*...*/] }
+```
 
-### Usage
+To specify the number of buckets for individual aggregation types, the object
+should instead use the `advancedParams` property, resembling
+```js
+{ advancedParams: [{ field: 'subject', size: 2 }, { field: 'creator', size: 4 }, /*...*/] }
+```
 
-```ts
-metadata.collection.value // return just the first item of the `values` array, ie. 'my-collection'
-metadata.collection.values // returns all values of the array, ie. ['my-collection', 'other-collection']
-metadata.collection.rawValue // return the rawValue. This is useful for inspecting the raw response received.
+However, these advanced aggregation parameters are not currently supported by the backend and may be removed at 
+a later date.
+
+#### `aggregationsSize`
+The number of buckets to be returned for all aggregation types.
+This defaults to 6 (the number of facets displayed for each type in the search results sidebar),
+but can be overridden using this parameter to retrieve more/fewer buckets as needed.
+
+#### `pageType`
+A string indicating what type of page this data is being requested for. The search backend may
+use a different set of default parameters depending on the page type. This defaults to
+`'search_results'`, and currently only supports `'search_results' | 'collection_details'`, with
+more types to be added in the future.
+
+#### `pageTarget`
+Used in conjunction with `pageType: 'collection_details'` to specify the identifier of the collection
+to retrieve results for.
+
+### Search types
+
+At present the only two types of search available are Metadata Search (`SearchType.METADATA`) 
+and Full Text Search (`SearchType.FULLTEXT`). This will eventually be extended to support other
+types of search including TV captions and radio transcripts. Calls that do not specify a search
+type will default to Metadata Search.
+
+### Return values
+
+Calls to `SearchService#search` will return a Promise that either resolves to a `SearchResponse`
+object or rejects with a `SearchServiceError`.
+
+`SearchResponse` objects are structured similar to this example:
+
+```js
+{
+  rawResponse: {/*...*/}, // The raw JSON fetched from the server
+  request: {
+    clientParameters: {/*...*/}, // The original client parameters sent with the request
+    finalizedParameters: {/*...*/} // The finalized request parameters as determined by the backend
+  },
+  responseHeader: {/*...*/}, // The header containing info about the response success/failure and processing time
+  response: {
+    totalResults: 12345, // The total number of search results matching the query
+    returnedCount: 50, // The number of search results returned in this response
+    results: [/*...*/], // The array of search results
+    aggregations: {/*...*/}, // A record mapping aggregation names to Aggregation objects
+    schema: {/*...*/} // The data schema to which the returned search results conform
+  }
+}
+```
 
-metadata.date.value  // return the date as a javascript `Date` object
+### Fetch Metadata
 
-metadata.length.value  // return the length (duration) of the item as a number of seconds, can be in the format "hh:mm:ss" or decimal seconds
-```
+As of v0.4.0, metadata fetching has been moved to the 
+[iaux-metadata-service](https://github.com/internetarchive/iaux-metadata-service) package
+and is no longer included as part of the Search Service.
 
 # Development
 
diff --git a/demo/app-root.ts b/demo/app-root.ts
index f0b1e4ce..bf7e89b2 100644
--- a/demo/app-root.ts
+++ b/demo/app-root.ts
@@ -1,20 +1,12 @@
-import {
-  css,
-  CSSResult,
-  customElement,
-  html,
-  internalProperty,
-  LitElement,
-  query,
-  TemplateResult,
-} from 'lit-element';
-import { unsafeHTML } from 'lit-html/directives/unsafe-html';
-import { nothing } from 'lit-html';
-import { Metadata } from '../src/models/metadata';
-import { MetadataResponse } from '../src/responses/metadata/metadata-response';
-import { SearchResponse } from '../src/responses/search/search-response';
+import { html, css, LitElement, TemplateResult, CSSResult, nothing } from 'lit';
+import { customElement, query, state } from 'lit/decorators.js';
+import { SearchResponse } from '../src/responses/search-response';
 import { SearchService } from '../src/search-service';
 import { SearchServiceInterface } from '../src/search-service-interface';
+import { SearchResult } from '../src/models/hit-types/hit';
+import { SearchType } from '../src/search-type';
+import { SearchParams, SortDirection } from '../src/search-params';
+import { Aggregation, Bucket } from '../src/models/aggregation';
 
 @customElement('app-root')
 export class AppRoot extends LitElement {
@@ -23,17 +15,36 @@ export class AppRoot extends LitElement {
   @query('#search-input')
   private searchInput!: HTMLInputElement;
 
-  @query('#metadata-input')
-  private metadataInput!: HTMLInputElement;
+  @query('#debug-info-check')
+  private debugCheck!: HTMLInputElement;
 
-  @internalProperty()
+  @query('#num-rows')
+  private rowsInput!: HTMLInputElement;
+
+  @query('#num-aggs')
+  private numAggsInput!: HTMLInputElement;
+
+  @query(`input[name='sort']:checked`)
+  private checkedSort!: HTMLInputElement;
+
+  @state()
   private searchResponse?: SearchResponse;
 
-  @internalProperty()
-  private metadataResponse?: MetadataResponse;
+  @state()
+  private aggregationsResponse?: SearchResponse;
+
+  @state()
+  private loadingSearchResults = false;
+
+  @state()
+  private loadingAggregations = false;
+
+  private get searchResults(): SearchResult[] | undefined {
+    return this.searchResponse?.response.results;
+  }
 
-  private get searchResults(): Metadata[] | undefined {
-    return this.searchResponse?.response.docs;
+  private get searchAggregations(): Record<string, Aggregation> | undefined {
+    return this.aggregationsResponse?.response.aggregations;
   }
 
   /** @inheritdoc */
@@ -42,27 +53,125 @@ export class AppRoot extends LitElement {
       <fieldset>
         <legend>Search</legend>
         <form>
-          <label>Search</label>
+          <label for="search-input">Search: </label>
           <input type="text" id="search-input" placeholder="Search Term" />
-          <input type="submit" value="Search" @click=${this.search} />
-        </form>
-        <form>
-          <label>Metadata</label>
-          <input type="text" id="metadata-input" placeholder="Identifier" />
-          <input
-            type="submit"
-            value="Get Metadata"
-            @click=${this.getMetadata}
-          />
+          <input type="submit" value="Go" @click=${this.search} />
+
+          <input type="checkbox" id="debug-info-check" />
+          <label for="debug-info-check">Include debugging info</label>
+
+          <fieldset class="search-options">
+            <legend>Search type:</legend>
+            <input
+              type="radio"
+              id="mds"
+              name="search-type"
+              value="mds"
+              checked
+            />
+            <label for="mds"> &nbsp;Metadata </label>
+            <input type="radio" id="fts" name="search-type" value="fts" />
+            <label for="fts"> &nbsp;Full text </label>
+          </fieldset>
+
+          <fieldset class="search-options">
+            <legend>Search size:</legend>
+            <div class="field-row">
+              <label for="num-rows">Number of result rows:</label>
+              <input type="number" id="num-rows" value="10" min="0" max="99" />
+            </div>
+            <div class="field-row">
+              <label for="num-aggs">Number of aggregation rows:</label>
+              <input type="number" id="num-aggs" value="6" min="0" max="50" />
+            </div>
+          </fieldset>
+
+          <fieldset class="search-options">
+            <legend>Sort by title:</legend>
+            <input
+              type="radio"
+              id="sort-none"
+              name="sort"
+              value="none"
+              checked
+            />
+            <label for="sort-none"> &nbsp;None </label>
+            <input type="radio" id="sort-asc" name="sort" value="asc" />
+            <label for="sort-asc"> &nbsp;Ascending </label>
+            <input type="radio" id="sort-desc" name="sort" value="desc" />
+            <label for="sort-desc"> &nbsp;Descending </label>
+          </fieldset>
+
+          <fieldset class="search-options">
+            <legend>Include aggregations for:</legend>
+            <input
+              type="checkbox"
+              id="aggs-subject"
+              name="aggs"
+              value="subject"
+              checked
+            />
+            <label for="aggs-subject">Subject </label>
+            <input
+              type="checkbox"
+              id="aggs-language"
+              name="aggs"
+              value="language"
+              checked
+            />
+            <label for="aggs-language">Language </label>
+            <input
+              type="checkbox"
+              id="aggs-creator"
+              name="aggs"
+              value="creator"
+              checked
+            />
+            <label for="aggs-creator">Creator </label>
+            <input
+              type="checkbox"
+              id="aggs-collection"
+              name="aggs"
+              value="collection"
+              checked
+            />
+            <label for="aggs-collection">Collection </label>
+            <input
+              type="checkbox"
+              id="aggs-mediatype"
+              name="aggs"
+              value="mediatype"
+              checked
+            />
+            <label for="aggs-mediatype">Mediatype </label>
+            <input
+              type="checkbox"
+              id="aggs-year"
+              name="aggs"
+              value="year"
+              checked
+            />
+            <label for="aggs-year"> &nbsp;Year </label>
+          </fieldset>
         </form>
       </fieldset>
 
       ${this.searchResults ? this.resultsTemplate : nothing}
-      ${this.metadataResponse ? this.metadataTemplate : nothing}
     `;
   }
 
   private get resultsTemplate(): TemplateResult {
+    return html`
+      ${this.loadingSearchResults
+        ? html`<h3>Loading search results...</h3>`
+        : this.searchResultsTemplate}
+      ${this.loadingAggregations
+        ? html`<h3>Loading aggregations...</h3>`
+        : this.aggregationsTemplate}
+    `;
+  }
+
+  private get searchResultsTemplate(): TemplateResult {
     return html`
       <h2>Search Results</h2>
       <table>
@@ -70,14 +179,16 @@ export class AppRoot extends LitElement {
           <tr>
             <th>Identifier</th>
             <th>Title</th>
+            ${this.snippetsHeaderTemplate}
           </tr>
         </thead>
         <tbody>
-          ${this.searchResults?.map(metadata => {
+          ${this.searchResults?.map(hit => {
             return html`
               <tr>
-                <td>${metadata.identifier}</td>
-                <td>${metadata.title?.value}</td>
+                <td>${hit.identifier}</td>
+                <td>${hit.title?.value ?? '(Untitled)'}</td>
+                ${this.snippetTemplate(hit)}
               </tr>
             `;
           })}
@@ -86,52 +197,128 @@ export class AppRoot extends LitElement {
     `;
   }
 
-  private get metadataTemplate(): TemplateResult {
-    const rawMetadata = this.metadataResponse?.metadata.rawMetadata;
-    if (!rawMetadata) return html`${nothing}`;
-
+  private get aggregationsTemplate(): TemplateResult {
     return html`
-      <h2>Metadata Response</h2>
-      <table>
-        ${Object.keys(rawMetadata).map(
-          key => html`
-            <tr>
-              <td>${key}</td>
-              <td>${unsafeHTML(rawMetadata[key])}</td>
-            </tr>
-          `
-        )}
-      </table>
+      <div>
+        <h2>Aggregations</h2>
+        ${Object.entries(this.searchAggregations ?? {}).map(([key, agg]) => {
+          return html`
+            <h3>${key}</h3>
+            <p>
+              ${agg.buckets
+                .map((bucket: number | Bucket) => {
+                  if (typeof bucket === 'number') {
+                    return bucket;
+                  } else {
+                    return `${bucket.key} (${bucket.doc_count})`;
+                  }
+                })
+                .join(', ')}
+            </p>
+          `;
+        })}
+      </div>
     `;
   }
 
-  async getMetadata(e: Event): Promise<void> {
-    e.preventDefault();
-    const identifier = this.metadataInput.value;
-    const result = await this.searchService.fetchMetadata(identifier);
-    this.metadataResponse = result?.success;
+  private get snippetsHeaderTemplate(): TemplateResult {
+    return this.searchResults?.some(hit => hit.highlight)
+      ? html`<th>Snippets</th>`
+      : html`${nothing}`;
   }
 
-  async search(e: Event): Promise<void> {
+  private snippetTemplate(hit: SearchResult): TemplateResult {
+    return hit.highlight
+      ? html`<td>${hit.highlight.value}</td>`
+      : html`${nothing}`;
+  }
+
+  /**
+   * Conduct a full search (both hits and aggregations)
+   */
+  private async search(e: Event): Promise<void> {
     e.preventDefault();
     const term = this.searchInput.value;
+
+    const checkedSearchType = this.shadowRoot?.querySelector(
+      `input[name='search-type']:checked`
+    ) as HTMLInputElement;
+
+    const searchType =
+      checkedSearchType?.value === 'fts'
+        ? SearchType.FULLTEXT
+        : SearchType.METADATA;
+
+    this.fetchSearchResults(term, searchType);
+    this.fetchAggregations(term, searchType);
+  }
+
+  /**
+   * Fetch the search hits
+   */
+  private async fetchSearchResults(query: string, searchType: SearchType) {
+    const sortParam =
+      this.checkedSort?.value === 'none'
+        ? []
+        : [
+            {
+              field: 'title',
+              direction: this.checkedSort?.value as SortDirection,
+            },
+          ];
+
+    const numRows = Number(this.rowsInput?.value);
+    const includeDebugging = this.debugCheck?.checked;
+
+    const searchParams: SearchParams = {
+      query,
+      rows: numRows,
+      fields: ['identifier', 'title'],
+      sort: sortParam,
+      aggregations: { omit: true },
+      debugging: includeDebugging,
+    };
+
+    this.loadingSearchResults = true;
+    const result = await this.searchService.search(searchParams, searchType);
+    this.loadingSearchResults = false;
+
+    if (result?.success) {
+      this.searchResponse = result?.success;
+    } else {
+      alert(`Oh noes: ${result?.error?.message}`);
+      console.error('Error searching', result?.error);
+    }
+  }
+
+  /**
+   * Fetch the search aggregations (facets)
+   */
+  private async fetchAggregations(query: string, searchType: SearchType) {
+    const checkedAggs = this.shadowRoot?.querySelectorAll(
+      `input[name='aggs']:checked`
+    );
     const aggregations = {
-      advancedParams: [
-        {
-          field: 'year',
-          size: 100,
-        },
-      ],
+      simpleParams: checkedAggs
+        ? [...checkedAggs].map(elmt => (elmt as HTMLInputElement).value)
+        : undefined,
     };
-    const searchParams = {
-      query: term,
-      rows: 10,
-      fields: ['identifier', 'title'],
+
+    const numAggs = Number(this.numAggsInput?.value);
+
+    const searchParams: SearchParams = {
+      query,
+      rows: 0,
       aggregations,
+      aggregationsSize: numAggs,
     };
-    const result = await this.searchService.search(searchParams);
+
+    this.loadingAggregations = true;
+    const result = await this.searchService.search(searchParams, searchType);
+    this.loadingAggregations = false;
+
     if (result?.success) {
-      this.searchResponse = result?.success;
+      this.aggregationsResponse = result?.success;
     } else {
       alert(`Oh noes: ${result?.error?.message}`);
       console.error('Error searching', result?.error);
@@ -140,9 +327,13 @@ export class AppRoot extends LitElement {
 
   static get styles(): CSSResult {
     return css`
-      /* th {
-        font-weight: bold;
-      } */
+      .search-options {
+        margin-top: 0.6rem;
+      }
+
+      .field-row {
+        margin: 0.3rem 0;
+      }
     `;
   }
 }
diff --git a/index.ts b/index.ts
index 9a244949..290e177e 100644
--- a/index.ts
+++ b/index.ts
@@ -1,8 +1,12 @@
 export { Metadata } from './src/models/metadata';
-export { File } from './src/models/file';
-export { Aggregation, Bucket } from './src/models/aggregation';
-export { Review } from './src/models/review';
-export { SpeechMusicASREntry } from './src/models/speech-music-asr-entry';
+export { ItemHit } from './src/models/hit-types/item-hit';
+export { TextHit } from './src/models/hit-types/text-hit';
+export { SearchResult, HitType } from './src/models/hit-types/hit';
+export {
+  Aggregation,
+  AggregationSortType,
+  Bucket,
+} from './src/models/aggregation';
 
 export { DateField } from './src/models/metadata-fields/field-types/date';
 
@@ -25,14 +29,17 @@ export {
   MetadataField,
 } from './src/models/metadata-fields/metadata-field';
 
-export { MetadataResponse } from './src/responses/metadata/metadata-response';
-export { SearchResponse } from './src/responses/search/search-response';
-export { SearchResponseHeader } from './src/responses/search/search-response-header';
-export { SearchResponseParams } from './src/responses/search/search-response-params';
+export { SearchResponse } from './src/responses/search-response';
+export { SearchResponseHeader } from './src/responses/search-response-header';
+export { SearchResponseParams } from './src/responses/search-response-params';
+
+export { MetadataSearchBackend } from './src/search-backend/metadata-search-backend';
+export { FulltextSearchBackend } from './src/search-backend/fulltext-search-backend';
 
-export { DefaultSearchBackend } from './src/search-backend/default-search-backend';
 export { SearchServiceInterface } from './src/search-service-interface';
 export { SearchService } from './src/search-service';
+export { SearchBackendOptionsInterface } from './src/search-backend/search-backend-options';
+export { SearchType } from './src/search-type';
 export {
   SearchParams,
   SortParam,
diff --git a/package-lock.json b/package-lock.json
index a450bdfc..290d0743 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@internetarchive/search-service",
-  "version": "0.3.5",
+  "version": "0.4.0-alpha.6",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "@internetarchive/search-service",
-      "version": "0.3.5",
+      "version": "0.4.0-alpha.6",
       "license": "AGPL-3.0-only",
       "dependencies": {
         "@internetarchive/field-parsers": "^0.1.3",
@@ -27,10 +27,10 @@
         "eslint-config-prettier": "^6.11.0",
         "husky": "^1.0.0",
         "lint-staged": "^10.0.0",
-        "lit-element": "^2.4.0",
-        "lit-html": "^1.3.0",
+        "lit": "^2.2.2",
         "madge": "^3.12.0",
         "prettier": "^2.0.4",
+        "sinon": "^12.0.1",
         "tslib": "^1.14.1",
         "typedoc": "^0.20.29",
         "typescript": "^4.2.2"
@@ -534,6 +534,12 @@
       "resolved": "https://registry.npmjs.org/@internetarchive/result-type/-/result-type-0.0.1.tgz",
       "integrity": "sha512-sWahff5oP1xAK1CwAu1/5GTG2RXsdx/sQKn4SSOWH0r0vU2QoX9kAom/jSXeBsmgK0IjTc+9Ty9407SMORi+nQ=="
     },
+    "node_modules/@lit/reactive-element": {
+      "version": "1.4.1",
+      "resolved": "https://registry.npmjs.org/@lit/reactive-element/-/reactive-element-1.4.1.tgz",
+      "integrity": "sha512-qDv4851VFSaBWzpS02cXHclo40jsbAjRXnebNXpm0uVg32kCneZPo9RYVQtrTNICtZ+1wAYHu1ZtxWSWMbKrBw==",
+      "dev": true
+    },
     "node_modules/@nodelib/fs.scandir": {
       "version": "2.1.3",
       "resolved": "https://registry.npmjs.org/@nodelib/fs.scandir/-/fs.scandir-2.1.3.tgz",
@@ -698,6 +704,41 @@
         "node": ">= 8.0.0"
       }
     },
+    "node_modules/@sinonjs/commons": {
+      "version": "1.8.3",
+      "resolved": "https://registry.npmjs.org/@sinonjs/commons/-/commons-1.8.3.tgz",
+      "integrity": "sha512-xkNcLAn/wZaX14RPlwizcKicDk9G3F8m2nU3L7Ukm5zBgTwiT0wsoFAHx9Jq56fJA1z/7uKGtCRu16sOUCLIHQ==",
+      "dev": true,
+      "dependencies": {
+        "type-detect": "4.0.8"
+      }
+    },
+    "node_modules/@sinonjs/fake-timers": {
+      "version": "8.1.0",
+      "resolved": "https://registry.npmjs.org/@sinonjs/fake-timers/-/fake-timers-8.1.0.tgz",
+      "integrity": "sha512-OAPJUAtgeINhh/TAlUID4QTs53Njm7xzddaVlEs/SXwgtiD1tW22zAB/W1wdqfrpmikgaWQ9Fw6Ws+hsiRm5Vg==",
+      "dev": true,
+      "dependencies": {
+        "@sinonjs/commons": "^1.7.0"
+      }
+    },
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+      "requires": {
+        "@sinonjs/commons": "^1.8.3",
+        "@sinonjs/fake-timers": "^8.1.0",
+        "@sinonjs/samsam": "^6.0.2",
+        "diff": "^5.0.0",
+        "nise": "^5.1.0",
+        "supports-color": "^7.2.0"
+      },
+      "dependencies": {
+        "diff": {
+          "version": "5.1.0",
+          "resolved": "https://registry.npmjs.org/diff/-/diff-5.1.0.tgz",
+          "integrity": "sha512-D+mk+qE8VC/PAUrlAU34N+VfXev0ghe5ywmpqrawphmVZc1bEfn56uo9qpyGp1p4xpzOHkSW4ztBd6L7Xx4ACw==",
+          "dev": true
+        },
+        "has-flag": {
+          "version": "4.0.0",
+          "resolved": "https://registry.npmjs.org/has-flag/-/has-flag-4.0.0.tgz",
+          "integrity": "sha512-EykJT/Q1KjTWctppgIAgfSO0tKVuZUjhgMr17kqTumMl6Afv3EISleU7qZUzoXDFTAHTDC4NOoG/ZxU3EvlMPQ==",
+          "dev": true
+        },
+        "supports-color": {
+          "version": "7.2.0",
+          "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-7.2.0.tgz",
+          "integrity": "sha512-qpCAvRl9stuOHveKsn7HncJRvv501qIacKzQlO/+Lwxc9+0q2wLyv4Dfvt80/DPn2pqOBsJdDiogXGR9+OvwRw==",
+          "dev": true,
+          "requires": {
+            "has-flag": "^4.0.0"
+          }
+        }
+      }
+    },
     "sinon-chai": {
       "version": "3.5.0",
       "resolved": "https://registry.npmjs.org/sinon-chai/-/sinon-chai-3.5.0.tgz",
diff --git a/package.json b/package.json
index 20f4818e..305c6a3b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@internetarchive/search-service",
-  "version": "0.3.5",
+  "version": "0.4.0",
   "description": "A search service for the Internet Archive",
   "license": "AGPL-3.0-only",
   "main": "dist/index.js",
@@ -38,10 +38,10 @@
     "eslint-config-prettier": "^6.11.0",
     "husky": "^1.0.0",
     "lint-staged": "^10.0.0",
-    "lit-element": "^2.4.0",
-    "lit-html": "^1.3.0",
+    "lit": "^2.2.2",
     "madge": "^3.12.0",
     "prettier": "^2.0.4",
+    "sinon": "^12.0.1",
     "tslib": "^1.14.1",
     "typedoc": "^0.20.29",
     "typescript": "^4.2.2"
diff --git a/src/models/aggregation.ts b/src/models/aggregation.ts
index b5ff10db..512ebb5f 100644
--- a/src/models/aggregation.ts
+++ b/src/models/aggregation.ts
@@ -1,3 +1,5 @@
+import { Memoize } from 'typescript-memoize';
+
 /**
  * A Bucket is an individual entry for a facet or bin for a histogram
  *
@@ -9,22 +11,86 @@ export interface Bucket {
   doc_count: number;
 }
 
-/**
- * Aggregations are the datasource for facets and histograms
- *
- * @export
- * @interface Aggregation
- */
-export interface Aggregation {
-  doc_count_error_upper_bound?: number;
-  sum_other_doc_count?: number;
+export enum AggregationSortType {
   /**
-   * The year_histogram returns a `number` array, and
-   * other facets return a `Bucket` array
+   * Sort descending numerically by count/frequency
+   */
+  COUNT,
+  /**
+   * Sort ascending alphabetically by key
    */
+  ALPHABETICAL,
+}
+
+export interface AggregationOptions {
   buckets: Bucket[] | number[];
+  doc_count_error_upper_bound?: number;
+  sum_other_doc_count?: number;
   first_bucket_key?: number;
   last_bucket_key?: number;
   number_buckets?: number;
   interval?: number;
 }
+
+/**
+ * Aggregations are the datasource for facets and histograms
+ */
+export class Aggregation {
+  /**
+   * The year_histogram returns a `number` array, and
+   * other facets return a `Bucket` array.
+   */
+  readonly buckets: Bucket[] | number[];
+  readonly doc_count_error_upper_bound?: number;
+  readonly sum_other_doc_count?: number;
+  readonly first_bucket_key?: number;
+  readonly last_bucket_key?: number;
+  readonly number_buckets?: number;
+  readonly interval?: number;
+
+  constructor(options: AggregationOptions) {
+    this.buckets = options.buckets;
+    this.doc_count_error_upper_bound = options.doc_count_error_upper_bound;
+    this.sum_other_doc_count = options.sum_other_doc_count;
+    this.first_bucket_key = options.first_bucket_key;
+    this.last_bucket_key = options.last_bucket_key;
+    this.number_buckets = options.number_buckets;
+    this.interval = options.interval;
+  }
+
+  /**
+   * Returns a sorted copy of this aggregation's buckets, according to the given sort option.
+   * This method is memoized and repeat calls should not incur a performance cost for a given
+   * sort type after the first such call per instance.
+   *
+   * Purely numeric buckets (e.g., year_histogram) are not sorted by this method and are
+   * returned as-is.
+   *
+   * @param sortType What to sort the buckets on.
+   * Accepted values are `AggregationSortType.COUNT` (descending order) and
+   * `AggregationSortType.ALPHABETICAL` (ascending order).
+   */
+  @Memoize()
+  getSortedBuckets(sortType?: AggregationSortType): Bucket[] | number[] {
+    // Don't apply sorts to numeric buckets.
+    // Assumption here is that all the buckets have the same type as the
+    // first bucket (which should be true in principle).
+    if (typeof this.buckets[0] === 'number') {
+      return [...(this.buckets as number[])];
+    }
+
+    // Default locale & collation options
+    const collator = new Intl.Collator();
+
+    switch (sortType) {
+      case AggregationSortType.ALPHABETICAL:
+        return [...(this.buckets as Bucket[])].sort((a, b) => {
+          return collator.compare(a.key.toString(), b.key.toString());
+        });
+      case AggregationSortType.COUNT:
+      default:
+        // Sorted by count by default
+        return [...(this.buckets as Bucket[])];
+    }
+  }
+}
diff --git a/src/models/file.ts b/src/models/file.ts
deleted file mode 100644
index c1cc4936..00000000
--- a/src/models/file.ts
+++ /dev/null
@@ -1,105 +0,0 @@
-/* eslint-disable @typescript-eslint/no-explicit-any */
-import { Memoize } from 'typescript-memoize';
-import {
-  Byte,
-  ByteParser,
-  Duration,
-  DurationParser,
-  NumberParser,
-} from '@internetarchive/field-parsers';
-
-/**
- * This represents an Internet Archive File
- *
- * @export
- * @class File
- */
-export class File {
-  rawValue: Record<string, any>;
-
-  get name(): string {
-    return this.rawValue.name;
-  }
-
-  get source(): string {
-    return this.rawValue.source;
-  }
-
-  get btih(): string {
-    return this.rawValue.btih;
-  }
-
-  get md5(): string {
-    return this.rawValue.md5;
-  }
-
-  get format(): string {
-    return this.rawValue.format;
-  }
-
-  get mtime(): string {
-    return this.rawValue.mtime;
-  }
-
-  get crc32(): string {
-    return this.rawValue.crc32;
-  }
-
-  get sha1(): string {
-    return this.rawValue.sha1;
-  }
-
-  get original(): string | undefined {
-    return this.rawValue.original;
-  }
-
-  @Memoize() get size(): Byte | undefined {
-    return this.rawValue.size
-      ? ByteParser.shared.parseValue(this.rawValue.size)
-      : undefined;
-  }
-
-  get title(): string | undefined {
-    return this.rawValue.title;
-  }
-
-  @Memoize() get length(): Duration | undefined {
-    return this.rawValue.length
-      ? DurationParser.shared.parseValue(this.rawValue.length)
-      : undefined;
-  }
-
-  @Memoize() get height(): number | undefined {
-    return this.rawValue.height
-      ? NumberParser.shared.parseValue(this.rawValue.height)
-      : undefined;
-  }
-
-  @Memoize() get width(): number | undefined {
-    return this.rawValue.width
-      ? NumberParser.shared.parseValue(this.rawValue.width)
-      : undefined;
-  }
-
-  @Memoize() get track(): number | undefined {
-    return this.rawValue.track
-      ? NumberParser.shared.parseValue(this.rawValue.track)
-      : undefined;
-  }
-
-  get external_identifier(): string | string[] | undefined {
-    return this.rawValue.external_identifier;
-  }
-
-  get creator(): string | undefined {
-    return this.rawValue.creator;
-  }
-
-  get album(): string | undefined {
-    return this.rawValue.album;
-  }
-
-  constructor(json: Record<string, any>) {
-    this.rawValue = json;
-  }
-}
diff --git a/src/models/hit-types/hit.ts b/src/models/hit-types/hit.ts
new file mode 100644
index 00000000..03e185b0
--- /dev/null
+++ b/src/models/hit-types/hit.ts
@@ -0,0 +1,23 @@
+import type { ItemHit } from './item-hit';
+import type { TextHit } from './text-hit';
+
+/**
+ * Union of the different hit_type values returned by the PPS.
+ * There will probably be more of these.
+ */
+export type HitType = 'item' | 'text';
+
+/**
+ * Applying this to the Result type forces Intellisense to present Result as
+ * a type in its own right, and not as the underlying merge type it aliases.
+ * Really just to keep things clean at the call site.
+ */
+interface PreserveAlias {} // eslint-disable-line @typescript-eslint/no-empty-interface
+
+/**
+ * Result is an expansive type definition encompassing all the optional
+ * and required properties that may occur on any type of search result
+ * ('hit') returned by the various search backends. (Most metadata
+ * properties are optional anyway).
+ */
+export type SearchResult = Partial<ItemHit & TextHit> & PreserveAlias;
diff --git a/src/models/hit-types/item-hit.ts b/src/models/hit-types/item-hit.ts
new file mode 100644
index 00000000..3938329c
--- /dev/null
+++ b/src/models/hit-types/item-hit.ts
@@ -0,0 +1,297 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import { Memoize } from 'typescript-memoize';
+import type { Metadata } from '../metadata';
+import { BooleanField } from '../metadata-fields/field-types/boolean';
+import { DateField } from '../metadata-fields/field-types/date';
+import { MediaTypeField } from '../metadata-fields/field-types/mediatype';
+import { NumberField } from '../metadata-fields/field-types/number';
+import { StringField } from '../metadata-fields/field-types/string';
+
+/**
+ * A model that describes an item hit from a Metadata Search via the PPS endpoint.
+ *
+ * The fields in here are cast to their respective field types. See `metadata-fields/field-type`.
+ *
+ * Add additional fields as needed.
+ *
+ * @export
+ * @class ItemHit
+ */
+export class ItemHit {
+  /**
+   * This is the raw hit response; useful for inspecting the raw data
+   * returned from the server.
+   */
+  rawMetadata?: Record<string, any>;
+
+  constructor(json: Record<string, any>) {
+    this.rawMetadata = json;
+  }
+
+  /**
+   * The item identifier.
+   *
+   * _Note_: This is a plain string instead of a `MetadataField` since it's
+   * the primary key of the item.
+   */
+  get identifier(): typeof Metadata.prototype.identifier {
+    return this.rawMetadata?.fields?.identifier;
+  }
+
+  /**
+   * May be a superset of metadata collection field.
+   * Multivalued.
+   */
+  @Memoize() get collection(): typeof Metadata.prototype.collection {
+    return this.rawMetadata?.fields?.collection
+      ? new StringField(this.rawMetadata.fields.collection)
+      : undefined;
+  }
+
+  /**
+   * Computed during document construction, for collection items only.
+   * Optional.
+   */
+  @Memoize() get collection_files_count(): NumberField | undefined {
+    return this.rawMetadata?.fields?.collection_files_count
+      ? new NumberField(this.rawMetadata.fields.collection_files_count)
+      : undefined;
+  }
+
+  /**
+   * In bytes; computed during document construction, for collection items only.
+   * Optional.
+   */
+  @Memoize() get collection_size(): typeof Metadata.prototype.collection_size {
+    return this.rawMetadata?.fields?.collection_size
+      ? new NumberField(this.rawMetadata.fields.collection_size)
+      : undefined;
+  }
+
+  /**
+   * Optional.
+   * Multivalued.
+   */
+  @Memoize() get creator(): typeof Metadata.prototype.creator {
+    return this.rawMetadata?.fields?.creator
+      ? new StringField(this.rawMetadata.fields.creator)
+      : undefined;
+  }
+
+  /**
+   * Optional.
+   */
+  @Memoize() get date(): typeof Metadata.prototype.date {
+    return this.rawMetadata?.fields?.date
+      ? new DateField(this.rawMetadata.fields.date)
+      : undefined;
+  }
+
+  /** Optional. */
+  @Memoize() get description(): typeof Metadata.prototype.description {
+    return this.rawMetadata?.fields?.description
+      ? new StringField(this.rawMetadata.fields.description)
+      : undefined;
+  }
+
+  /**
+   * Total views over item lifetime, updated by audit consultation with Views API.
+   * Optional.
+   */
+  @Memoize() get downloads(): typeof Metadata.prototype.downloads {
+    return this.rawMetadata?.fields?.downloads
+      ? new NumberField(this.rawMetadata.fields.downloads)
+      : undefined;
+  }
+
+  /**
+   * Computed during document construction.
+   */
+  @Memoize() get files_count(): typeof Metadata.prototype.files_count {
+    return this.rawMetadata?.fields?.files_count
+      ? new NumberField(this.rawMetadata.fields.files_count)
+      : undefined;
+  }
+
+  /**
+   * Optional.
+   * Multivalued.
+   */
+  @Memoize() get genre(): StringField | undefined {
+    return this.rawMetadata?.fields?.genre
+      ? new StringField(this.rawMetadata.fields.genre)
+      : undefined;
+  }
+
+  /**
+   * Item characterization including noindex status.
+   * Multivalued.
+   */
+  @Memoize() get indexflag(): StringField | undefined {
+    return this.rawMetadata?.fields?.indexflag
+      ? new StringField(this.rawMetadata.fields.indexflag)
+      : undefined;
+  }
+
+  /**
+   * In bytes; computed during document construction.
+   */
+  @Memoize() get item_size(): typeof Metadata.prototype.item_size {
+    return this.rawMetadata?.fields?.item_size
+      ? new NumberField(this.rawMetadata.fields.item_size)
+      : undefined;
+  }
+
+  /**
+   * Optional.
+   * Multivalued.
+   */
+  @Memoize() get language(): typeof Metadata.prototype.language {
+    return this.rawMetadata?.fields?.language
+      ? new StringField(this.rawMetadata.fields.language)
+      : undefined;
+  }
+
+  /**
+   * May be stale.
+   * Optional.
+   */
+  @Memoize() get lending___available_to_borrow(): BooleanField | undefined {
+    return this.rawMetadata?.fields?.lending___available_to_borrow != null
+      ? new BooleanField(this.rawMetadata.fields.lending___available_to_borrow)
+      : undefined;
+  }
+
+  /**
+   * May be stale.
+   * Optional.
+   */
+  @Memoize() get lending___available_to_browse(): BooleanField | undefined {
+    return this.rawMetadata?.fields?.lending___available_to_browse != null
+      ? new BooleanField(this.rawMetadata.fields.lending___available_to_browse)
+      : undefined;
+  }
+
+  /**
+   * May be stale.
+   * Optional.
+   */
+  @Memoize() get lending___available_to_waitlist(): BooleanField | undefined {
+    return this.rawMetadata?.fields?.lending___available_to_waitlist != null
+      ? new BooleanField(
+          this.rawMetadata.fields.lending___available_to_waitlist
+        )
+      : undefined;
+  }
+
+  /**
+   * May be stale.
+   * Optional.
+   */
+  @Memoize() get lending___status(): StringField | undefined {
+    return this.rawMetadata?.fields?.lending___status
+      ? new StringField(this.rawMetadata.fields.lending___status)
+      : undefined;
+  }
+
+  /** Optional. */
+  @Memoize() get licenseurl(): StringField | undefined {
+    return this.rawMetadata?.fields?.licenseurl
+      ? new StringField(this.rawMetadata.fields.licenseurl)
+      : undefined;
+  }
+
+  @Memoize() get mediatype(): typeof Metadata.prototype.mediatype {
+    return this.rawMetadata?.fields?.mediatype
+      ? new MediaTypeField(this.rawMetadata.fields.mediatype)
+      : undefined;
+  }
+
+  /**
+   * Views over a month, updated by audit consultation with Views API.
+   * Optional.
+   */
+  @Memoize() get month(): typeof Metadata.prototype.month {
+    return this.rawMetadata?.fields?.month
+      ? new NumberField(this.rawMetadata.fields.month)
+      : undefined;
+  }
+
+  /** Optional. */
+  @Memoize() get noindex(): typeof Metadata.prototype.noindex {
+    return this.rawMetadata?.fields?.noindex != null
+      ? new BooleanField(this.rawMetadata.fields.noindex)
+      : undefined;
+  }
+
+  /**
+   * Computed during document construction.
+   * Optional.
+   */
+  @Memoize() get num_favorites(): typeof Metadata.prototype.num_favorites {
+    return this.rawMetadata?.fields?.num_favorites
+      ? new NumberField(this.rawMetadata.fields.num_favorites)
+      : undefined;
+  }
+
+  /**
+   * Computed during document construction.
+   * Optional.
+   */
+  @Memoize() get num_reviews(): typeof Metadata.prototype.num_reviews {
+    return this.rawMetadata?.fields?.num_reviews
+      ? new NumberField(this.rawMetadata.fields.num_reviews)
+      : undefined;
+  }
+
+  /**
+   * Optional.
+   * Multivalued.
+   */
+  @Memoize() get subject(): StringField | undefined {
+    return this.rawMetadata?.fields?.subject
+      ? new StringField(this.rawMetadata.fields.subject)
+      : undefined;
+  }
+
+  /** Optional. */
+  @Memoize() get title(): typeof Metadata.prototype.title {
+    return this.rawMetadata?.fields?.title
+      ? new StringField(this.rawMetadata.fields.title)
+      : undefined;
+  }
+
+  /** Optional. */
+  @Memoize() get type(): typeof Metadata.prototype.type {
+    return this.rawMetadata?.fields?.type
+      ? new StringField(this.rawMetadata.fields.type)
+      : undefined;
+  }
+
+  /** Optional. */
+  @Memoize() get volume(): typeof Metadata.prototype.volume {
+    return this.rawMetadata?.fields?.volume
+      ? new StringField(this.rawMetadata.fields.volume)
+      : undefined;
+  }
+
+  /**
+   * Views over a seven-day period, updated by audit consultation with Views API.
+   * Optional.
+   */
+  @Memoize() get week(): typeof Metadata.prototype.week {
+    return this.rawMetadata?.fields?.week
+      ? new NumberField(this.rawMetadata.fields.week)
+      : undefined;
+  }
+
+  /**
+   * Computed from date.
+   * Optional.
+   */
+  @Memoize() get year(): NumberField | undefined {
+    return this.rawMetadata?.fields?.year
+      ? new NumberField(this.rawMetadata.fields.year)
+      : undefined;
+  }
+}
diff --git a/src/models/hit-types/text-hit.ts b/src/models/hit-types/text-hit.ts
new file mode 100644
index 00000000..c40de2a0
--- /dev/null
+++ b/src/models/hit-types/text-hit.ts
@@ -0,0 +1,199 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import { Memoize } from 'typescript-memoize';
+import type { Metadata } from '../metadata';
+import { BooleanField } from '../metadata-fields/field-types/boolean';
+import { DateField } from '../metadata-fields/field-types/date';
+import { MediaTypeField } from '../metadata-fields/field-types/mediatype';
+import { NumberField } from '../metadata-fields/field-types/number';
+import { StringField } from '../metadata-fields/field-types/string';
+
+/**
+ * A model that describes a textual hit from a full text search via the PPS endpoint.
+ *
+ * The fields in here are cast to their respective field types. See `metadata-fields/field-type`.
+ *
+ * Add additional fields as needed.
+ *
+ * @export
+ * @class TextHit
+ */
+export class TextHit {
+  /**
+   * This is the raw hit response; useful for inspecting the raw data
+   * returned from the server.
+   */
+  rawMetadata?: Record<string, any>;
+
+  constructor(json: Record<string, any>) {
+    this.rawMetadata = json;
+  }
+
+  /**
+   * The item identifier.
+   *
+   * _Note_: This is a plain string instead of a `MetadataField` since it's
+   * the primary key of the item.
+   */
+  get identifier(): typeof Metadata.prototype.identifier {
+    return this.rawMetadata?.fields?.identifier;
+  }
+
+  /**
+   * Synthesized in processing of FTS API hit; TBD
+   * Optional.
+   */
+  @Memoize() get highlight(): StringField | undefined {
+    // Note: _not_ inside the fields object.
+    return this.rawMetadata?.highlight?.text
+      ? new StringField(this.rawMetadata.highlight.text)
+      : undefined;
+  }
+
+  /** Multivalued. */
+  @Memoize() get collection(): typeof Metadata.prototype.collection {
+    return this.rawMetadata?.fields?.collection
+      ? new StringField(this.rawMetadata.fields.collection)
+      : undefined;
+  }
+
+  @Memoize() get created_on(): DateField | undefined {
+    return this.rawMetadata?.fields?.created_on
+      ? new DateField(this.rawMetadata.fields.created_on)
+      : undefined;
+  }
+
+  /**
+   * Optional.
+   * Multivalued.
+   */
+  @Memoize() get creator(): typeof Metadata.prototype.creator {
+    return this.rawMetadata?.fields?.creator
+      ? new StringField(this.rawMetadata.fields.creator)
+      : undefined;
+  }
+
+  /** Optional. */
+  @Memoize() get date(): typeof Metadata.prototype.date {
+    return this.rawMetadata?.fields?.date
+      ? new DateField(this.rawMetadata.fields.date)
+      : undefined;
+  }
+
+  /**
+   * Contents of hilighting in FTS API hit, TBD
+   * Optional.
+   * Multivalued.
+   */
+  @Memoize() get description(): typeof Metadata.prototype.description {
+    return this.rawMetadata?.fields?.description
+      ? new StringField(this.rawMetadata.fields.description)
+      : undefined;
+  }
+
+  /**
+   * Total views over ITEM (not text) lifetime, updated by audit consultation with Views API.
+   * Optional.
+   */
+  @Memoize() get downloads(): typeof Metadata.prototype.downloads {
+    return this.rawMetadata?.fields?.downloads
+      ? new NumberField(this.rawMetadata.fields.downloads)
+      : undefined;
+  }
+
+  @Memoize() get filename(): StringField | undefined {
+    return this.rawMetadata?.fields?.filename
+      ? new StringField(this.rawMetadata.fields.filename)
+      : undefined;
+  }
+
+  @Memoize() get file_basename(): StringField | undefined {
+    return this.rawMetadata?.fields?.file_basename
+      ? new StringField(this.rawMetadata.fields.file_basename)
+      : undefined;
+  }
+
+  @Memoize() get file_creation_mtime(): NumberField | undefined {
+    return this.rawMetadata?.fields?.file_creation_mtime
+      ? new NumberField(this.rawMetadata.fields.file_creation_mtime)
+      : undefined;
+  }
+
+  @Memoize() get mediatype(): typeof Metadata.prototype.mediatype {
+    return this.rawMetadata?.fields?.mediatype
+      ? new MediaTypeField(this.rawMetadata.fields.mediatype)
+      : undefined;
+  }
+
+  /** Optional. */
+  @Memoize() get page_num(): NumberField | undefined {
+    return this.rawMetadata?.fields?.page_num
+      ? new NumberField(this.rawMetadata.fields.page_num)
+      : undefined;
+  }
+
+  /** Optional. */
+  @Memoize() get publicdate(): typeof Metadata.prototype.publicdate {
+    return this.rawMetadata?.fields?.publicdate
+      ? new DateField(this.rawMetadata.fields.publicdate)
+      : undefined;
+  }
+
+  /**
+   * Computed in processing of FTS API hit.
+   */
+  @Memoize() get result_in_subfile(): BooleanField | undefined {
+    return this.rawMetadata?.fields?.result_in_subfile != null
+      ? new BooleanField(this.rawMetadata.fields.result_in_subfile)
+      : undefined;
+  }
+
+  /** Optional. */
+  @Memoize() get reviewdate(): typeof Metadata.prototype.reviewdate {
+    return this.rawMetadata?.fields?.reviewdate
+      ? new DateField(this.rawMetadata.fields.reviewdate)
+      : undefined;
+  }
+
+  /**
+   * Optional.
+   * Multivalued.
+   */
+  @Memoize() get subject(): StringField | undefined {
+    return this.rawMetadata?.fields?.subject
+      ? new StringField(this.rawMetadata.fields.subject)
+      : undefined;
+  }
+
+  /** Optional. */
+  @Memoize() get title(): typeof Metadata.prototype.title {
+    return this.rawMetadata?.fields?.title
+      ? new StringField(this.rawMetadata.fields.title)
+      : undefined;
+  }
+
+  @Memoize() get updated_on(): DateField | undefined {
+    return this.rawMetadata?.fields?.updated_on
+      ? new DateField(this.rawMetadata.fields.updated_on)
+      : undefined;
+  }
+
+  /**
+   * Computed from date.
+   * Optional.
+   */
+  @Memoize() get year(): NumberField | undefined {
+    return this.rawMetadata?.fields?.year
+      ? new NumberField(this.rawMetadata.fields.year)
+      : undefined;
+  }
+
+  /**
+   * Synthesized in processing of FTS API hit; TBD
+   * Optional.
+   */
+  @Memoize() get __href__(): StringField | undefined {
+    return this.rawMetadata?.fields?.__href__
+      ? new StringField(this.rawMetadata.fields.__href__)
+      : undefined;
+  }
+}
diff --git a/src/models/metadata.ts b/src/models/metadata.ts
index b6730609..00009a24 100644
--- a/src/models/metadata.ts
+++ b/src/models/metadata.ts
@@ -260,7 +260,7 @@ export class Metadata {
   }
 
   @Memoize() get noindex(): BooleanField | undefined {
-    return this.rawMetadata?.noindex
+    return this.rawMetadata?.noindex != null
       ? new BooleanField(this.rawMetadata.noindex)
       : undefined;
   }
@@ -349,12 +349,6 @@ export class Metadata {
       : undefined;
   }
 
-  @Memoize() get snippets(): StringField | undefined {
-    return this.rawMetadata?.snippets
-      ? new StringField(this.rawMetadata.snippets)
-      : undefined;
-  }
-
   @Memoize() get source(): StringField | undefined {
     return this.rawMetadata?.source
       ? new StringField(this.rawMetadata.source)
diff --git a/src/models/review.ts b/src/models/review.ts
deleted file mode 100644
index 9ab3eacd..00000000
--- a/src/models/review.ts
+++ /dev/null
@@ -1,41 +0,0 @@
-/* eslint-disable @typescript-eslint/no-explicit-any */
-import { Memoize } from 'typescript-memoize';
-import { DateParser, NumberParser } from '@internetarchive/field-parsers';
-
-export class Review {
-  rawValue: Record<string, any>;
-
-  get reviewbody(): string | undefined {
-    return this.rawValue.reviewbody;
-  }
-
-  get reviewtitle(): string | undefined {
-    return this.rawValue.reviewtitle;
-  }
-
-  get reviewer(): string | undefined {
-    return this.rawValue.reviewer;
-  }
-
-  @Memoize() get reviewdate(): Date | undefined {
-    return this.rawValue.reviewdate
-      ? DateParser.shared.parseValue(this.rawValue.reviewdate)
-      : undefined;
-  }
-
-  @Memoize() get createdate(): Date | undefined {
-    return this.rawValue.createdate
-      ? DateParser.shared.parseValue(this.rawValue.createdate)
-      : undefined;
-  }
-
-  @Memoize() get stars(): number | undefined {
-    return this.rawValue.stars
-      ? NumberParser.shared.parseValue(this.rawValue.stars)
-      : undefined;
-  }
-
-  constructor(json: Record<string, any>) {
-    this.rawValue = json;
-  }
-}
diff --git a/src/models/speech-music-asr-entry.ts b/src/models/speech-music-asr-entry.ts
deleted file mode 100644
index b73b4a47..00000000
--- a/src/models/speech-music-asr-entry.ts
+++ /dev/null
@@ -1,10 +0,0 @@
-/**
- * This is the format used for radio transcripts
- */
-export interface SpeechMusicASREntry {
-  end: number;
-  id: number;
-  is_music: boolean;
-  start: number;
-  text: string;
-}
diff --git a/src/responses/metadata/metadata-response.ts b/src/responses/metadata/metadata-response.ts
deleted file mode 100644
index 669f5720..00000000
--- a/src/responses/metadata/metadata-response.ts
+++ /dev/null
@@ -1,61 +0,0 @@
-/* eslint-disable @typescript-eslint/no-explicit-any */
-import { File } from '../../models/file';
-import { Metadata } from '../../models/metadata';
-import { Review } from '../../models/review';
-import { SpeechMusicASREntry } from '../../models/speech-music-asr-entry';
-
-/**
- * The main top-level reponse when fetching Metadata
- *
- * @export
- * @class MetadataResponse
- */
-export class MetadataResponse {
-  rawResponse: any;
-
-  created: number;
-
-  d1: string;
-
-  d2: string;
-
-  dir: string;
-
-  files: File[];
-
-  files_count: number;
-
-  item_last_updated: number;
-
-  item_size: number;
-
-  metadata: Metadata;
-
-  server: string;
-
-  uniq: number;
-
-  workable_servers: string[];
-
-  speech_vs_music_asr?: SpeechMusicASREntry[];
-
-  reviews?: Review[];
-
-  constructor(json: Record<string, any>) {
-    this.rawResponse = json;
-    this.created = json.created;
-    this.d1 = json.d1;
-    this.d2 = json.d2;
-    this.dir = json.dir;
-    this.files = json.files?.map((file: any) => new File(file));
-    this.files_count = json.files_count;
-    this.item_last_updated = json.item_last_updated;
-    this.item_size = json.item_size;
-    this.metadata = new Metadata(json.metadata);
-    this.server = json.server;
-    this.uniq = json.uniq;
-    this.workable_servers = json.workable_servers;
-    this.speech_vs_music_asr = json.speech_vs_music_asr;
-    this.reviews = json.reviews?.map((entry: any) => new Review(entry));
-  }
-}
diff --git a/src/responses/search-hit-schema.ts b/src/responses/search-hit-schema.ts
new file mode 100644
index 00000000..7f3bd2e2
--- /dev/null
+++ b/src/responses/search-hit-schema.ts
@@ -0,0 +1,28 @@
+import { HitType } from '../models/hit-types/hit';
+
+/**
+ * Schema for individual field types within a hit
+ */
+export interface FieldSchema {
+  mapping: string;
+  multivalue: boolean;
+  optional?: boolean;
+  comment?: string;
+}
+
+/**
+ * Top-level schema structure returned by the PPS
+ */
+export interface SearchHitSchema {
+  /**
+   * A string identifying what type of hits were returned
+   * (and which this schema describes)
+   */
+  hit_type: HitType;
+
+  /**
+   * A map of the fields present on each search hit, with info
+   * about their type and whether they are optional or multivalued.
+   */
+  field_properties: Record<string, FieldSchema>;
+}
diff --git a/src/responses/search-request-params.ts b/src/responses/search-request-params.ts
new file mode 100644
index 00000000..0671de2a
--- /dev/null
+++ b/src/responses/search-request-params.ts
@@ -0,0 +1,23 @@
+/**
+ * The server-parsed request parameters that are returned
+ * with responses from the PPS endpoint.
+ *
+ * While similar in structure to the `SearchParams` passed
+ * into a `search` call, this interface describes the _parsed_
+ * parameters as the server has interpreted them (e.g., with
+ * raw sort and aggregation strings rather than the structured
+ * objects that callers pass with a query).
+ */
+export interface SearchRequestParams {
+  client?: string;
+  user_query?: string;
+  service_backend?: string;
+  page_type?: string;
+  page_target?: string;
+  page?: number;
+  hits_per_page?: number;
+  fields?: string[];
+  sort?: string[];
+  aggregations?: string[];
+  aggregations_size?: number;
+}
diff --git a/src/responses/search-request.ts b/src/responses/search-request.ts
new file mode 100644
index 00000000..73eddd2b
--- /dev/null
+++ b/src/responses/search-request.ts
@@ -0,0 +1,22 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import { SearchRequestParams } from './search-request-params';
+
+/**
+ * A model for the request parameters returned with each search response.
+ */
+export class SearchRequest {
+  /**
+   * The original client parameters sent with the request
+   */
+  clientParameters: SearchRequestParams;
+
+  /**
+   * The finalized request parameters as determined by the backend
+   */
+  finalizedParameters: SearchRequestParams;
+
+  constructor(json: Record<string, any>) {
+    this.clientParameters = json.client_parameters;
+    this.finalizedParameters = json.finalized_parameters;
+  }
+}
diff --git a/src/responses/search-response-details.ts b/src/responses/search-response-details.ts
new file mode 100644
index 00000000..edc94fb5
--- /dev/null
+++ b/src/responses/search-response-details.ts
@@ -0,0 +1,100 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import { Aggregation } from '../models/aggregation';
+import { SearchResult, HitType } from '../models/hit-types/hit';
+import { ItemHit } from '../models/hit-types/item-hit';
+import { TextHit } from '../models/hit-types/text-hit';
+import type { SearchHitSchema } from './search-hit-schema';
+
+/**
+ * The structure of the response body returned from the PPS endpoint.
+ */
+export interface SearchResponseBody {
+  hits: SearchResponseHits;
+  aggregations?: Record<string, Aggregation>;
+}
+
+/**
+ * The structure of the response body `hits` object returned from the PPS endpoint.
+ */
+export interface SearchResponseHits {
+  total: number;
+  returned: number;
+  hits: Record<string, any>[];
+}
+
+/**
+ * This is the search response details inside the SearchResponse object that contains
+ * the search results, under the `results` key.
+ *
+ * @export
+ */
+export class SearchResponseDetails {
+  /**
+   * Total number of results found
+   */
+  totalResults: number;
+
+  /**
+   * Number of returned hits in this response
+   */
+  returnedCount: number;
+
+  /**
+   * The array of search results
+   */
+  results: SearchResult[];
+
+  /**
+   * Requested aggregations such as facets or histogram data
+   *
+   * @type {Record<string, Aggregation>}
+   * @memberof SearchResponseDetails
+   */
+  aggregations?: Record<string, Aggregation>;
+
+  /**
+   * The hit schema for this response
+   */
+  schema?: SearchHitSchema;
+
+  constructor(body: SearchResponseBody, schema: SearchHitSchema) {
+    this.schema = schema;
+    const hitType = schema?.hit_type;
+
+    this.totalResults = body?.hits?.total ?? 0;
+    this.returnedCount = body?.hits?.returned ?? 0;
+    this.results =
+      body?.hits?.hits?.map((hit: SearchResult) =>
+        SearchResponseDetails.createResult(hitType, hit)
+      ) ?? [];
+
+    // Construct Aggregation objects
+    if (body?.aggregations) {
+      this.aggregations = Object.entries(body.aggregations).reduce(
+        (acc, [key, val]) => {
+          acc[key] = new Aggregation(val);
+          return acc;
+        },
+        {} as Record<string, Aggregation>
+      );
+    }
+  }
+
+  /**
+   * Returns a correctly-typed search result depending on the schema's hit_type.
+   */
+  private static createResult(
+    type: HitType,
+    result: SearchResult
+  ): SearchResult {
+    switch (type) {
+      case 'item':
+        return new ItemHit(result);
+      case 'text':
+        return new TextHit(result);
+      default:
+        // The hit type doesn't tell us what to construct, so just return the input as-is
+        return result;
+    }
+  }
+}
diff --git a/src/responses/search-response-header.ts b/src/responses/search-response-header.ts
new file mode 100644
index 00000000..df245021
--- /dev/null
+++ b/src/responses/search-response-header.ts
@@ -0,0 +1,4 @@
+export interface SearchResponseHeader {
+  succeeded: boolean;
+  query_time: number;
+}
diff --git a/src/responses/search/search-response-params.ts b/src/responses/search-response-params.ts
similarity index 100%
rename from src/responses/search/search-response-params.ts
rename to src/responses/search-response-params.ts
diff --git a/src/responses/search/search-response.ts b/src/responses/search-response.ts
similarity index 64%
rename from src/responses/search/search-response.ts
rename to src/responses/search-response.ts
index 20c5c8da..bd68d927 100644
--- a/src/responses/search/search-response.ts
+++ b/src/responses/search-response.ts
@@ -1,9 +1,10 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
 import { SearchResponseHeader } from './search-response-header';
 import { SearchResponseDetails } from './search-response-details';
+import { SearchRequest } from './search-request';
 
 /**
- * The top-level response model when retrieving a response from the advanced search endpoint.
+ * The top-level response model when retrieving a response from the page production service endpoint.
  *
  * @export
  * @class SearchResponse
@@ -18,7 +19,13 @@ export class SearchResponse {
   rawResponse: Record<string, any>;
 
   /**
-   * The resonse header
+   * The request object returned by the backend, specifying the query parameters and
+   * how the backend interpreted them.
+   */
+  request: SearchRequest;
+
+  /**
+   * The response header
    *
    * @type {SearchResponseHeader}
    * @memberof SearchResponse
@@ -35,7 +42,11 @@ export class SearchResponse {
 
   constructor(json: Record<string, any>) {
     this.rawResponse = json;
-    this.responseHeader = json.responseHeader;
-    this.response = new SearchResponseDetails(json.response);
+    this.request = new SearchRequest(json.request);
+    this.responseHeader = json.response?.header;
+    this.response = new SearchResponseDetails(
+      json.response?.body,
+      json.response?.hit_schema
+    );
   }
 }
diff --git a/src/responses/search/search-response-details.ts b/src/responses/search/search-response-details.ts
deleted file mode 100644
index 0d62adb3..00000000
--- a/src/responses/search/search-response-details.ts
+++ /dev/null
@@ -1,51 +0,0 @@
-/* eslint-disable @typescript-eslint/no-explicit-any */
-import { Aggregation } from '../../models/aggregation';
-import { Metadata } from '../../models/metadata';
-
-/**
- * This is the search response details inside the SearchResponse object that contains
- * the search results, under the `docs` key.
- *
- * @export
- * @class Response
- */
-export class SearchResponseDetails {
-  /**
-   * Total number of results found
-   *
-   * @type {number}
-   * @memberof Response
-   */
-  numFound: number;
-
-  /**
-   * Search result start number for pagination
-   *
-   * @type {number}
-   * @memberof Response
-   */
-  start: number;
-
-  /**
-   * The array of search results
-   *
-   * @type {Metadata[]}
-   * @memberof Response
-   */
-  docs: Metadata[];
-
-  /**
-   * Requested aggregations such as facets or histogram data
-   *
-   * @type {Record<string, Aggregation>}
-   * @memberof SearchResponseDetails
-   */
-  aggregations?: Record<string, Aggregation>;
-
-  constructor(json: SearchResponseDetails) {
-    this.numFound = json.numFound;
-    this.start = json.start;
-    this.docs = json.docs.map((doc: any) => new Metadata(doc));
-    this.aggregations = json.aggregations;
-  }
-}
diff --git a/src/responses/search/search-response-header.ts b/src/responses/search/search-response-header.ts
deleted file mode 100644
index 9d2a148c..00000000
--- a/src/responses/search/search-response-header.ts
+++ /dev/null
@@ -1,8 +0,0 @@
-/* eslint-disable @typescript-eslint/no-explicit-any */
-import { SearchResponseParams } from './search-response-params';
-
-export interface SearchResponseHeader {
-  status: number;
-  QTime: number;
-  params: SearchResponseParams;
-}
diff --git a/src/search-backend/default-search-backend.ts b/src/search-backend/base-search-backend.ts
similarity index 66%
rename from src/search-backend/default-search-backend.ts
rename to src/search-backend/base-search-backend.ts
index 71885802..6e897a6d 100644
--- a/src/search-backend/default-search-backend.ts
+++ b/src/search-backend/base-search-backend.ts
@@ -1,28 +1,28 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
 import { SearchBackendInterface } from './search-backend-interface';
-import { SearchParams } from '../search-params';
-import { Result } from '@internetarchive/result-type';
+import type { SearchParams } from '../search-params';
+import type { Result } from '@internetarchive/result-type';
 import {
   SearchServiceError,
   SearchServiceErrorType,
 } from '../search-service-error';
-import { SearchParamURLGenerator } from '../search-param-url-generator';
+import type { SearchBackendOptionsInterface } from './search-backend-options';
 
 /**
- * The DefaultSearchBackend performs a `window.fetch` request to archive.org
+ * An abstract base class for search backends.
  */
-export class DefaultSearchBackend implements SearchBackendInterface {
-  private baseUrl: string;
+export abstract class BaseSearchBackend implements SearchBackendInterface {
+  /**
+   * The base URL / host this backend should use for its requests.
+   * Defaults to 'archive.org'.
+   */
+  protected baseUrl: string;
 
-  private includeCredentials: boolean;
+  protected includeCredentials: boolean;
 
-  private requestScope?: string;
+  protected requestScope?: string;
 
-  constructor(options?: {
-    baseUrl?: string;
-    includeCredentials?: boolean;
-    scope?: string;
-  }) {
+  constructor(options?: SearchBackendOptionsInterface) {
     this.baseUrl = options?.baseUrl ?? 'archive.org';
 
     if (options?.includeCredentials !== undefined) {
@@ -49,34 +49,16 @@ export class DefaultSearchBackend implements SearchBackendInterface {
   }
 
   /** @inheritdoc */
-  async performSearch(
+  abstract performSearch(
     params: SearchParams
-  ): Promise<Result<any, SearchServiceError>> {
-    const urlSearchParam = SearchParamURLGenerator.generateURLSearchParams(
-      params
-    );
-    const queryAsString = urlSearchParam.toString();
-    const url = `https://${this.baseUrl}/advancedsearch.php?${queryAsString}`;
-    return this.fetchUrl(url);
-  }
-
-  /** @inheritdoc */
-  async fetchMetadata(
-    identifier: string,
-    keypath?: string
-  ): Promise<Result<any, SearchServiceError>> {
-    const path = keypath ? `/${keypath}` : '';
-    const url = `https://${this.baseUrl}/metadata/${identifier}${path}`;
-    // the metadata endpoint doesn't current support credentialed requests
-    // so don't include credentials until that is fixed
-    return this.fetchUrl(url, {
-      requestOptions: {
-        credentials: 'omit',
-      },
-    });
-  }
+  ): Promise<Result<any, SearchServiceError>>;
 
-  private async fetchUrl(
+  /**
+   * Fires a request to the URL (with this backend's options applied) and
+   * asynchronously returns a Result object containing either the raw response
+   * JSON or a SearchServiceError.
+   */
+  protected async fetchUrl(
     url: string,
     options?: {
       requestOptions?: RequestInit;
@@ -107,6 +89,11 @@ export class DefaultSearchBackend implements SearchBackendInterface {
     // then try json decoding and return a decodingError if it fails
     try {
       const json = await response.json();
+
+      if (json['debugging']) {
+        this.printDebuggingInfo(json);
+      }
+
       // the advanced search endpoint doesn't return an HTTP Error 400
       // and instead returns an HTTP 200 with an `error` key in the payload
       const error = json['error'];
@@ -141,4 +128,25 @@ export class DefaultSearchBackend implements SearchBackendInterface {
     const result = { error };
     return result;
   }
+
+  /**
+   * Logs PPS debugging info to the console if it is present on the response object
+   */
+  private printDebuggingInfo(json: Record<string, any>) {
+    const debugInfo = json.debugging?.debugging; // PPS debugging info is doubly-nested, not sure why
+    const messages = debugInfo?.messages ?? [];
+    const data = debugInfo?.data ?? {};
+
+    console.group('Debug messages');
+    for (const message of messages) {
+      console.log(message);
+    }
+    console.groupEnd();
+
+    console.group('Debug data');
+    for (const [key, val] of Object.entries(data)) {
+      console.log(key, val);
+    }
+    console.groupEnd();
+  }
 }
diff --git a/src/search-backend/fulltext-search-backend.ts b/src/search-backend/fulltext-search-backend.ts
new file mode 100644
index 00000000..d76073d1
--- /dev/null
+++ b/src/search-backend/fulltext-search-backend.ts
@@ -0,0 +1,36 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import type { SearchParams } from '../search-params';
+import type { Result } from '@internetarchive/result-type';
+import type { SearchServiceError } from '../search-service-error';
+import { SearchParamURLGenerator } from '../search-param-url-generator';
+import { BaseSearchBackend } from './base-search-backend';
+import type { SearchBackendOptionsInterface } from './search-backend-options';
+
+/**
+ * The FulltextSearchBackend performs a `window.fetch` request to archive.org
+ */
+export class FulltextSearchBackend extends BaseSearchBackend {
+  private servicePath: string;
+
+  constructor(
+    options?: SearchBackendOptionsInterface & {
+      servicePath?: string;
+    }
+  ) {
+    super(options);
+    this.servicePath =
+      options?.servicePath ?? '/services/search/beta/page_production';
+  }
+
+  /** @inheritdoc */
+  async performSearch(
+    params: SearchParams
+  ): Promise<Result<any, SearchServiceError>> {
+    const urlSearchParam = SearchParamURLGenerator.generateURLSearchParams(
+      params
+    );
+    const queryAsString = urlSearchParam.toString();
+    const url = `https://${this.baseUrl}${this.servicePath}/?service_backend=fts&${queryAsString}`;
+    return this.fetchUrl(url);
+  }
+}
diff --git a/src/search-backend/metadata-search-backend.ts b/src/search-backend/metadata-search-backend.ts
new file mode 100644
index 00000000..5dde6d5f
--- /dev/null
+++ b/src/search-backend/metadata-search-backend.ts
@@ -0,0 +1,36 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import type { SearchParams } from '../search-params';
+import type { Result } from '@internetarchive/result-type';
+import type { SearchServiceError } from '../search-service-error';
+import { SearchParamURLGenerator } from '../search-param-url-generator';
+import { BaseSearchBackend } from './base-search-backend';
+import type { SearchBackendOptionsInterface } from './search-backend-options';
+
+/**
+ * The MetadataSearchBackend performs a `window.fetch` request to archive.org
+ */
+export class MetadataSearchBackend extends BaseSearchBackend {
+  private servicePath: string;
+
+  constructor(
+    options?: SearchBackendOptionsInterface & {
+      servicePath?: string;
+    }
+  ) {
+    super(options);
+    this.servicePath =
+      options?.servicePath ?? '/services/search/beta/page_production';
+  }
+
+  /** @inheritdoc */
+  async performSearch(
+    params: SearchParams
+  ): Promise<Result<any, SearchServiceError>> {
+    const urlSearchParam = SearchParamURLGenerator.generateURLSearchParams(
+      params
+    );
+    const queryAsString = urlSearchParam.toString();
+    const url = `https://${this.baseUrl}${this.servicePath}/?service_backend=metadata&${queryAsString}`;
+    return this.fetchUrl(url);
+  }
+}
diff --git a/src/search-backend/search-backend-interface.ts b/src/search-backend/search-backend-interface.ts
index 3d453610..9d63243c 100644
--- a/src/search-backend/search-backend-interface.ts
+++ b/src/search-backend/search-backend-interface.ts
@@ -1,14 +1,13 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
-import { Result } from '@internetarchive/result-type';
-import { SearchParams } from '../search-params';
-import { SearchServiceError } from '../search-service-error';
+import type { Result } from '@internetarchive/result-type';
+import type { SearchParams } from '../search-params';
+import type { SearchServiceError } from '../search-service-error';
 
 /**
  * An interface to provide the network layer to the `SearchService`.
  *
  * Objects implementing this interface are responsible for making calls to the Internet Archive
- * `advancedsearch` and `metadata` endpoints or otherwise providing a similar reponse in JSON
- * format.
+ * search endpoints or otherwise providing a similar reponse in JSON format.
  *
  * This allows for projects like the DWeb project to provide
  * alternative datasources for a request.
@@ -23,15 +22,4 @@ export interface SearchBackendInterface {
    * @param params
    */
   performSearch(params: SearchParams): Promise<Result<any, SearchServiceError>>;
-
-  /**
-   * Fetch metadata for a single item with an optional keypath
-   *
-   * @param identifier
-   * @param keypath
-   */
-  fetchMetadata(
-    identifier: string,
-    keypath?: string
-  ): Promise<Result<any, SearchServiceError>>;
 }
diff --git a/src/search-backend/search-backend-options.ts b/src/search-backend/search-backend-options.ts
new file mode 100644
index 00000000..d913e590
--- /dev/null
+++ b/src/search-backend/search-backend-options.ts
@@ -0,0 +1,12 @@
+/**
+ * Options that can be passed to a search backend constructor
+ */
+export interface SearchBackendOptionsInterface {
+  /**
+   * The base URL / host this backend should use for its requests.
+   * Defaults to 'archive.org'.
+   */
+  baseUrl?: string;
+  includeCredentials?: boolean;
+  scope?: string;
+}
diff --git a/src/search-param-url-generator.ts b/src/search-param-url-generator.ts
index dd8a27d7..91e80b20 100644
--- a/src/search-param-url-generator.ts
+++ b/src/search-param-url-generator.ts
@@ -25,12 +25,16 @@ export class SearchParamURLGenerator {
    *  }
    * ]
    *
-   * @returns string | undefined}
+   * @returns {string | undefined}
    * @memberof AggregateSearchParams
    */
   static aggregateSearchParamsAsString(
     aggregateSearchParams: AggregateSearchParams
   ): string | undefined {
+    if (aggregateSearchParams.omit) {
+      return 'false';
+    }
+
     if (aggregateSearchParams.advancedParams) {
       const params = aggregateSearchParams.advancedParams.map(param => {
         return {
@@ -47,24 +51,31 @@ export class SearchParamURLGenerator {
   }
 
   static sortParamsAsString(sortParams: SortParam): string {
-    return `${sortParams.field} ${sortParams.direction}`;
+    return `${sortParams.field}:${sortParams.direction}`;
   }
 
   static generateURLSearchParams(searchParams: SearchParams): URLSearchParams {
     const params: URLSearchParams = new URLSearchParams();
-    params.append('q', searchParams.query);
-    params.append('output', 'json');
+    params.append('user_query', searchParams.query);
+
+    if (searchParams.pageType) {
+      params.append('page_type', String(searchParams.pageType));
+    }
+
+    if (searchParams.pageTarget) {
+      params.append('page_target', String(searchParams.pageTarget));
+    }
 
-    if (searchParams.rows) {
-      params.append('rows', String(searchParams.rows));
+    if (searchParams.rows != null) {
+      params.append('hits_per_page', String(searchParams.rows));
     }
 
-    if (searchParams.page) {
+    if (searchParams.page != null) {
       params.append('page', String(searchParams.page));
     }
 
     if (searchParams.fields) {
-      params.append('fl', searchParams.fields.join(','));
+      params.append('fields', searchParams.fields.join(','));
     }
 
     if (searchParams.sort) {
@@ -78,10 +89,18 @@ export class SearchParamURLGenerator {
     if (aggregations) {
       const aggString = this.aggregateSearchParamsAsString(aggregations);
       if (aggString) {
-        params.append('user_aggs', aggString);
+        params.append('aggregations', aggString);
       }
     }
 
+    if (searchParams.aggregationsSize != null) {
+      params.append('aggregations_size', String(searchParams.aggregationsSize));
+    }
+
+    if (searchParams.debugging) {
+      params.append('debugging', 'true');
+    }
+
     return params;
   }
 }
diff --git a/src/search-params.ts b/src/search-params.ts
index 3be4f0a4..28ec5caf 100644
--- a/src/search-params.ts
+++ b/src/search-params.ts
@@ -3,16 +3,48 @@ export interface AggregateSearchParam {
   size?: number;
 }
 
+/**
+ * An object specifying which aggregation types should be returned with
+ * a search query.
+ */
 export interface AggregateSearchParams {
+  /**
+   * An array of objects each specifying both a field name for which
+   * aggregations should be returned and the number of "buckets" that
+   * should be returned for it.
+   *
+   * Note: this format may not be supported by all backends. Run some
+   * test queries with advanced aggregation objects before relying on this.
+   */
   advancedParams?: AggregateSearchParam[];
 
+  /**
+   * An array of field names for which aggregations should be returned.
+   */
   simpleParams?: string[];
+
+  /**
+   * A flag to indicate that aggregations should be omitted entirely
+   * from the response (e.g., to retrieve only search results without
+   * the added time cost of generating aggregations for them).
+   *
+   * Setting this to `true` in a search call will result in a response
+   * with `undefined` aggregations.
+   */
+  omit?: boolean;
 }
 
 export type SortDirection = 'asc' | 'desc';
 
 export interface SortParam {
+  /**
+   * The name of the field to sort on (e.g., 'title').
+   */
   field: string;
+
+  /**
+   * Which direction to sort in ('asc' or 'desc').
+   */
   direction: SortDirection;
 }
 
@@ -20,20 +52,74 @@ export interface SortParam {
  * SearchParams provides an encapsulation to all of the search parameters
  * available for searching.
  *
- * It also provides an `asUrlSearchParams` method for converting the
- * parameters to an IA-style query string. ie. it converts the `fields` array
- * to `fl=identifier,collection` and `sort` to `sort=date+desc,downloads+asc`
+ * We use `SearchParamURLGenerator.generateUrlSearchParams` to convert the
+ * parameters to a PPS-conforming query string -- i.e., it converts the
+ * `fields` array to `fields=identifier,collection` and `sort` to
+ * `sort=date:desc,downloads:asc`
  */
 export interface SearchParams {
+  /**
+   * The query string to search for.
+   */
   query: string;
 
+  /**
+   * The page type to generate results for (e.g., 'search_results').
+   *
+   * Defaults to 'search_results' in the PPS. Meant to allow different
+   * backend defaults to be used depending on the needs of certain pages.
+   */
+  pageType?: string;
+
+  /**
+   * For collection details pages, specifies the name of the collection
+   * that is to be retrieved (e.g., 'prelinger').
+   */
+  pageTarget?: string;
+
+  /**
+   * One or more parameters specifying how the search results should be
+   * sorted. Each parameter should include the field name and sort direction,
+   * e.g.: `{ field: 'title', sort: 'desc' }`
+   */
   sort?: SortParam[];
 
+  /**
+   * The number of results to be retrieved per page.
+   */
   rows?: number;
 
+  /**
+   * The page number to be retrieved (beginning from page 1).
+   *
+   * Note that the _size_ of each page is determined by the `rows` parameter.
+   */
   page?: number;
 
+  /**
+   * A list of fields that should be retrieved for each search result. In most
+   * cases it should be unnecessary to specify the fields parameter as it is
+   * defaulted by the PPS depending on the page_type. However, it may be useful
+   * in some cases to restrict which fields are returned to a smaller subset of
+   * the defaults.
+   */
   fields?: string[];
 
+  /**
+   * An object specifying which aggregation types should be returned with
+   * a search query.
+   */
   aggregations?: AggregateSearchParams;
+
+  /**
+   * The number of buckets that should be returned for each aggregation type.
+   * This defaults to 6 in the PPS (the number of facets displayed for each
+   * facet type by default in the sidebar).
+   */
+  aggregationsSize?: number;
+
+  /**
+   * Whether to include debugging info in the returned PPS response.
+   */
+  debugging?: boolean;
 }
diff --git a/src/search-service-interface.ts b/src/search-service-interface.ts
index 7effc6aa..ddad1e35 100644
--- a/src/search-service-interface.ts
+++ b/src/search-service-interface.ts
@@ -1,65 +1,21 @@
-import { MetadataResponse } from './responses/metadata/metadata-response';
-import { Result } from '@internetarchive/result-type';
-import { SearchResponse } from './responses/search/search-response';
-import { SearchParams } from './search-params';
-import { SearchServiceError } from './search-service-error';
+import type { Result } from '@internetarchive/result-type';
+import type { SearchResponse } from './responses/search-response';
+import type { SearchParams } from './search-params';
+import type { SearchServiceError } from './search-service-error';
+import type { SearchType } from './search-type';
 
 export interface SearchServiceInterface {
   /**
-   * Perform a search for given search params
+   * Perform a search for given search params.
    *
-   * @param {SearchParams} params
+   * @param {SearchParams} params Params object specifying the search query,
+   * sorting/aggregation options, and other ways to adjust what is returned.
+   * @param {SearchType} searchType What type of search to perform (e.g.,
+   * metadata or full text)
    * @returns {Promise<Result<SearchResponse, SearchServiceError>>}
-   * @memberof SearchServiceInterface
    */
   search(
-    params: SearchParams
+    params: SearchParams,
+    searchType?: SearchType
   ): Promise<Result<SearchResponse, SearchServiceError>>;
-
-  /**
-   * Fetch metadata for a given identifier
-   *
-   * @param {string} identifier
-   * @returns {Promise<Result<MetadataResponse, SearchServiceError>>}
-   * @memberof SearchServiceInterface
-   */
-  fetchMetadata(
-    identifier: string
-  ): Promise<Result<MetadataResponse, SearchServiceError>>;
-
-  /**
-   * Fetch the metadata value for a given identifier and keypath
-   *
-   * The response from this request can take any form, object, array, string, etc.
-   * depending on the query. You can provide return typing in the response by
-   * specifying the type. Note, there is no automatic type conversion since it can be anything.
-   *
-   * For example:
-   *
-   * ```ts
-   * const collection = await searchService.fetchMetadataValue<string>('goody', 'metadata/collection/0');
-   * console.debug('collection:', collection); => 'Goody Collection'
-   *
-   * const files_count = await searchService.fetchMetadataValue<number>('goody', 'files_count');
-   * console.debug('files_count:', files_count); => 12
-   * ```
-   *
-   * Keypath examples:
-   *
-   * /metadata/:identifier/metadata // returns the entire metadata object
-   * /metadata/:identifier/server // returns the server for the given identifier
-   * /metadata/:identifier/files_count
-   * /metadata/:identifier/files?start=1&count=2 // query for files
-   * /metadata/:identifier/metadata/collection // all collections
-   * /metadata/:identifier/metadata/collection/0 // first collection
-   * /metadata/:identifier/metadata/title
-   * /metadata/:identifier/files/0/name // first file name
-   *
-   * @param identifier
-   * @param keypath
-   */
-  fetchMetadataValue<T>(
-    identifier: string,
-    keypath: string
-  ): Promise<Result<T, SearchServiceError>>;
 }
diff --git a/src/search-service.ts b/src/search-service.ts
index 11fac818..f9bff041 100644
--- a/src/search-service.ts
+++ b/src/search-service.ts
@@ -1,79 +1,69 @@
-import { SearchResponse } from './responses/search/search-response';
-import { SearchParams } from './search-params';
-import { MetadataResponse } from './responses/metadata/metadata-response';
-import { DefaultSearchBackend } from './search-backend/default-search-backend';
-import {
-  SearchServiceError,
-  SearchServiceErrorType,
-} from './search-service-error';
-import { SearchServiceInterface } from './search-service-interface';
-import { SearchBackendInterface } from './search-backend/search-backend-interface';
-import { Result } from '@internetarchive/result-type';
+import { SearchResponse } from './responses/search-response';
+import type { SearchParams } from './search-params';
+import type { SearchServiceError } from './search-service-error';
+import type { SearchServiceInterface } from './search-service-interface';
+import type { Result } from '@internetarchive/result-type';
+import { SearchType } from './search-type';
+import type { SearchBackendOptionsInterface } from './search-backend/search-backend-options';
+import type { SearchBackendInterface } from './search-backend/search-backend-interface';
+import { FulltextSearchBackend } from './search-backend/fulltext-search-backend';
+import { MetadataSearchBackend } from './search-backend/metadata-search-backend';
+import { Memoize } from 'typescript-memoize';
 
 /**
  * The Search Service is responsible for taking the raw response provided by
- * the Search Backend and modeling it as a `SearchResponse` or `MetadataResponse`
- * object, depending on the type of response.
+ * the Search Backend and modeling it as a `SearchResponse` object.
  */
 export class SearchService implements SearchServiceInterface {
-  public static default: SearchServiceInterface = new SearchService(
-    new DefaultSearchBackend()
-  );
+  public static default: SearchServiceInterface = new SearchService();
 
-  private searchBackend: SearchBackendInterface;
+  private backendOptions: SearchBackendOptionsInterface;
 
-  constructor(searchBackend: SearchBackendInterface) {
-    this.searchBackend = searchBackend;
+  constructor(backendOptions: SearchBackendOptionsInterface = {}) {
+    this.backendOptions = backendOptions;
   }
 
   /** @inheritdoc */
   async search(
-    params: SearchParams
+    params: SearchParams,
+    searchType: SearchType = SearchType.METADATA
   ): Promise<Result<SearchResponse, SearchServiceError>> {
-    const rawResponse = await this.searchBackend.performSearch(params);
-    if (rawResponse.error) {
-      return rawResponse;
-    }
-
-    const modeledResponse = new SearchResponse(rawResponse.success);
-    return { success: modeledResponse };
-  }
+    const searchBackend = SearchService.getBackendForSearchType(
+      searchType,
+      this.backendOptions
+    );
 
-  /** @inheritdoc */
-  async fetchMetadata(
-    identifier: string
-  ): Promise<Result<MetadataResponse, SearchServiceError>> {
-    const rawResponse = await this.searchBackend.fetchMetadata(identifier);
+    const rawResponse = await searchBackend.performSearch(params);
     if (rawResponse.error) {
       return rawResponse;
     }
 
-    if (rawResponse.success?.metadata === undefined) {
-      return {
-        error: new SearchServiceError(SearchServiceErrorType.itemNotFound),
-      };
-    }
-
-    const modeledResponse = new MetadataResponse(rawResponse.success);
+    const modeledResponse = new SearchResponse(rawResponse.success);
     return { success: modeledResponse };
   }
 
-  /** @inheritdoc */
-  async fetchMetadataValue<T>(
-    identifier: string,
-    keypath: string
-  ): Promise<Result<T, SearchServiceError>> {
-    const result = await this.searchBackend.fetchMetadata(identifier, keypath);
-    if (result.error) {
-      return result;
+  /**
+   * Retrieve a search backend that can handle the given type of search.
+   * @param type The type of search that the backend needs to handle.
+   * @param options Options to pass to the search backend.
+   */
+  @Memoize((type: SearchType, options: SearchBackendOptionsInterface = {}) => {
+    // We can memoize backends based on their params, to avoid constructing redundant backends
+    const { includeCredentials = '', scope = '', baseUrl = '' } = options;
+    return `${type};${includeCredentials};${scope};${baseUrl}`;
+  })
+  static getBackendForSearchType(
+    type: SearchType,
+    options: SearchBackendOptionsInterface = {}
+  ): SearchBackendInterface {
+    switch (type) {
+      //case SearchType.TV: // Will eventually have its own service backend
+      //case SearchType.RADIO: // Will eventually have its own service backend
+      case SearchType.FULLTEXT:
+        return new FulltextSearchBackend(options);
+      case SearchType.METADATA:
+      default:
+        return new MetadataSearchBackend(options);
     }
-
-    if (result.success?.result === undefined) {
-      return {
-        error: new SearchServiceError(SearchServiceErrorType.itemNotFound),
-      };
-    }
-
-    return { success: result.success.result };
   }
 }
diff --git a/src/search-type.ts b/src/search-type.ts
new file mode 100644
index 00000000..4d245a56
--- /dev/null
+++ b/src/search-type.ts
@@ -0,0 +1,10 @@
+/**
+ * An enum specifying the different types of search that can be conducted
+ * through the SearchService.
+ */
+export enum SearchType {
+  METADATA,
+  FULLTEXT,
+  //TV, // not yet available
+  //RADIO, // not yet available
+}
diff --git a/test/default-search-backend.test.ts b/test/default-search-backend.test.ts
deleted file mode 100644
index 4f87ab41..00000000
--- a/test/default-search-backend.test.ts
+++ /dev/null
@@ -1,143 +0,0 @@
-/* eslint-disable @typescript-eslint/no-unused-vars */
-/* eslint-disable @typescript-eslint/no-explicit-any */
-import { expect } from '@open-wc/testing';
-
-import { SearchParams } from '../src/search-params';
-
-import { SearchServiceErrorType } from '../src/search-service-error';
-import { DefaultSearchBackend } from '../src/search-backend/default-search-backend';
-
-describe('DefaultSearchBackend', () => {
-  it('can fetch metadata', async () => {
-    const fetchBackup = window.fetch;
-    window.fetch = (): Promise<Response> => {
-      return new Promise(resolve => {
-        const response = new Response('{ "foo": "bar" }');
-        resolve(response);
-      });
-    };
-
-    const backend = new DefaultSearchBackend();
-    const result = await backend.fetchMetadata('foo');
-    expect(result.success?.foo).to.equal('bar');
-    window.fetch = fetchBackup;
-  });
-
-  it('can perform a search', async () => {
-    const fetchBackup = window.fetch;
-    window.fetch = (): Promise<Response> => {
-      return new Promise(resolve => {
-        const response = new Response('{ "foo": "bar" }');
-        resolve(response);
-      });
-    };
-
-    const backend = new DefaultSearchBackend();
-    const params = { query: 'foo' };
-    const result = await backend.performSearch(params);
-    expect(result.success?.foo).to.equal('bar');
-    window.fetch = fetchBackup;
-  });
-
-  it('returns a networkError if theres a problem fetching using String type', async () => {
-    const fetchBackup = window.fetch;
-    window.fetch = (): Promise<Response> => {
-      throw 'network error';
-    };
-
-    const backend = new DefaultSearchBackend();
-    const result = await backend.fetchMetadata('foo');
-    expect(result.error?.type).to.equal(SearchServiceErrorType.networkError);
-    expect(result.error?.message).to.equal('network error');
-    window.fetch = fetchBackup;
-  });
-
-  it('returns a networkError if theres a problem fetching using Error type', async () => {
-    const fetchBackup = window.fetch;
-    window.fetch = (): Promise<Response> => {
-      throw new Error('network error');
-    };
-
-    const backend = new DefaultSearchBackend();
-    const result = await backend.fetchMetadata('foo');
-    expect(result.error?.type).to.equal(SearchServiceErrorType.networkError);
-    expect(result.error?.message).to.equal('network error');
-    window.fetch = fetchBackup;
-  });
-
-  it('returns a decodingError if theres a problem decoding the json', async () => {
-    const fetchBackup = window.fetch;
-    window.fetch = (): Promise<Response> => {
-      const response = new Response('boop');
-      return new Promise(resolve => resolve(response));
-    };
-
-    const backend = new DefaultSearchBackend();
-    const result = await backend.fetchMetadata('foo');
-    expect(result.error?.type).to.equal(SearchServiceErrorType.decodingError);
-    window.fetch = fetchBackup;
-  });
-
-  it('appends the scope if provided', async () => {
-    const fetchBackup = window.fetch;
-    let urlCalled = '';
-    window.fetch = (url: RequestInfo): Promise<Response> => {
-      urlCalled = url.toString();
-      const response = new Response('boop');
-      return new Promise(resolve => resolve(response));
-    };
-
-    const backend = new DefaultSearchBackend({
-      scope: 'foo',
-    });
-    const result = await backend.fetchMetadata('foo');
-    expect(urlCalled.includes('scope=foo')).to.be.true;
-    window.fetch = fetchBackup;
-  });
-
-  it('includes credentials for search endpoint if requested', async () => {
-    const fetchBackup = window.fetch;
-    let urlCalled: RequestInfo;
-    let urlConfig: RequestInit | undefined;
-    window.fetch = (
-      url: RequestInfo,
-      config?: RequestInit
-    ): Promise<Response> => {
-      urlCalled = url;
-      urlConfig = config;
-      const response = new Response('boop');
-      return new Promise(resolve => resolve(response));
-    };
-
-    const backend = new DefaultSearchBackend({
-      scope: 'foo',
-      includeCredentials: true,
-    });
-    await backend.performSearch({ query: 'foo' });
-    expect(urlConfig?.credentials).to.equal('include');
-    window.fetch = fetchBackup;
-  });
-
-  it('does not credentials for metadata endpoint', async () => {
-    const fetchBackup = window.fetch;
-    let urlCalled: RequestInfo;
-    let urlConfig: RequestInit | undefined;
-    window.fetch = (
-      url: RequestInfo,
-      config?: RequestInit
-    ): Promise<Response> => {
-      urlCalled = url;
-      urlConfig = config;
-      const response = new Response('boop');
-      return new Promise(resolve => resolve(response));
-    };
-
-    const backend = new DefaultSearchBackend({
-      scope: 'foo',
-      includeCredentials: true,
-    });
-    await backend.fetchMetadata('foo');
-    expect(urlConfig?.credentials).to.equal('omit');
-    window.fetch = fetchBackup;
-  });
-});
diff --git a/test/mock-response-generator.ts b/test/mock-response-generator.ts
index 09a92ee6..5186162f 100644
--- a/test/mock-response-generator.ts
+++ b/test/mock-response-generator.ts
@@ -1,102 +1,114 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
-
-import { SearchResponse } from '../src/responses/search/search-response';
 import { SearchParams } from '../src/search-params';
-import { Metadata } from '../src/models/metadata';
+import { ItemHit } from '../src/models/hit-types/item-hit';
+import { TextHit } from '../src/models/hit-types/text-hit';
 
 export class MockResponseGenerator {
-  generateMockSearchResponse(params: SearchParams): SearchResponse {
-    const fieldsAsString = params.fields?.join(',');
-
-    const metadata1 = new Metadata({ identifier: 'foo' });
-    const metadata2 = new Metadata({ identifier: 'bar' });
+  generateMockMetadataSearchResponse(
+    params: SearchParams
+  ): Record<string, any> {
+    const metadata1 = new ItemHit({ identifier: 'foo' });
+    const metadata2 = new ItemHit({ identifier: 'bar' });
 
     return {
       rawResponse: {
         foo: 'bar',
       },
-      responseHeader: {
-        status: 0,
-        QTime: 1459,
-        params: {
-          query: params.query,
-          qin: params.query,
-          fields: fieldsAsString ?? '',
-          wt: 'json',
-          sort: params.sort?.reduce((prev, current, index) => {
-            const isFirst = index === 0;
-            const commaPrefix = isFirst ? '' : ', ';
-            return `${prev}${commaPrefix}${current.field} ${current.direction}`;
-          }, ''),
-          rows: params.rows ? `${params.rows}` : '',
-          start: params.page ?? 0,
+      request: {
+        client_parameters: {
+          client: 'page_production_service_endpoint',
+          user_query: params.query,
+          page: params.page ?? 0,
+          hits_per_page: params.rows ?? 0,
+          fields: params.fields ?? [],
+        },
+        finalized_parameters: {
+          client: 'page_production_service_endpoint',
+          user_query: params.query,
+          service_backend: 'metadata',
+          page: params.page ?? 0,
+          page_type: 'search_results',
+          hits_per_page: 50,
+          fields: ['_tile_'].concat(params.fields ?? []),
+          sort: ['_score'],
+          aggregations: [
+            'mediatype',
+            'year',
+            'subject',
+            'collection',
+            'creator',
+            'language',
+          ],
+          aggregations_size: 6,
         },
       },
+      responseHeader: {
+        succeeded: true,
+        query_time: 3133,
+      },
       response: {
-        numFound: 12345,
-        start: 0,
-        docs: [metadata1, metadata2],
+        totalResults: 12345,
+        returnedCount: 2,
+        results: [metadata1, metadata2],
+        schema: {
+          hit_type: 'item',
+          field_properties: {},
+        },
       },
     };
   }
 
-  generateMockMetadataResponse(identifier: string): any {
+  generateMockFulltextSearchResponse(
+    params: SearchParams
+  ): Record<string, any> {
+    const text1 = new TextHit({ identifier: 'foo' });
+    const text2 = new TextHit({ identifier: 'bar' });
+
     return {
-      created: 1586477049,
-      d1: 'ia600201.us.archive.org',
-      d2: 'ia800201.us.archive.org',
-      dir: '/27/items/rss-383924main_TWAN_09_04_09',
-      files: [
-        {
-          name: 'foo.jpg',
-          source: 'derivative',
-          format: 'Thumbnail',
-          original: 'foo.mp4',
-          md5: '48067b43a547d3e90cb433a04ba84d5d',
-          mtime: '1256675427',
-          size: '1135',
-          crc32: '40870038',
-          sha1: '6445c2a6f51c8314c1872ec1f7daf33c5cfabd06',
+      rawResponse: {
+        foo: 'bar',
+      },
+      request: {
+        client_parameters: {
+          client: 'page_production_service_endpoint',
+          user_query: params.query,
+          page: params.page ?? 0,
+          hits_per_page: params.rows ?? 0,
+          fields: params.fields ?? [],
+        },
+        finalized_parameters: {
+          client: 'page_production_service_endpoint',
+          user_query: params.query,
+          service_backend: 'fts',
+          page: params.page ?? 0,
+          page_type: 'search_results',
+          hits_per_page: 50,
+          fields: ['_tile_'].concat(params.fields ?? []),
+          sort: ['_score'],
+          aggregations: [
+            'mediatype',
+            'year',
+            'subject',
+            'collection',
+            'creator',
+            'language',
+          ],
+          aggregations_size: 6,
         },
-        {
-          name: 'bar.jpg',
-          source: 'derivative',
-          format: 'Thumbnail',
-          original: 'bar.mp4',
-          md5: '5bf69912d7b796fe309cde32e61230bc',
-          mtime: '1256675429',
-          size: '6329',
-          crc32: 'ba5f361a',
-          sha1: 'cddab0e2daab29978e5efdeff735240a44aa7c80',
+      },
+      responseHeader: {
+        succeeded: true,
+        query_time: 3133,
+      },
+      response: {
+        totalResults: 12345,
+        returnedCount: 2,
+        results: [text1, text2],
+        schema: {
+          hit_type: 'text',
+          field_properties: {},
         },
-      ],
-      files_count: 2,
-      item_last_updated: 1463797130,
-      item_size: 99872691,
-      metadata: {
-        feed_id:
-          '/0/rss_feeds/NASACast_Video/nasacast_video:sts128_landing/NASAcast_vodcast.rss',
-        mediatype: 'movies',
-        title: "NASA TV's This Week @NASA, September 4",
-        description: "NASA TV's This Week @NASA, September 4",
-        creator: 'NASA',
-        source: 'http://www.nasa.gov/multimedia/podcasting/twan_09_04_09.html',
-        date: '9/4/2009',
-        year: '2009',
-        rights: 'Public Domain',
-        language: 'en-us',
-        updater: 'BonnieReal',
-        updatedate: '2009-10-27 20:23:01',
-        identifier,
-        uploader: 'bonnie@archive.org',
-        addeddate: '2009-10-27 20:25:55',
-        publicdate: '2009-10-27 20:41:27',
-        collection: ['nasa', 'nasacastvideo'],
-        backup_location: 'ia903604_7',
       },
-      server: 'ia800201.us.archive.org',
-      uniq: 162444403,
-      workable_servers: ['ia800201.us.archive.org', 'ia600201.us.archive.org'],
     };
   }
 }
diff --git a/test/models/file.test.ts b/test/models/file.test.ts
deleted file mode 100644
index 6ca7b91c..00000000
--- a/test/models/file.test.ts
+++ /dev/null
@@ -1,10 +0,0 @@
-import { expect } from '@open-wc/testing';
-
-import { File } from '../../src/models/file';
-
-describe('File', () => {
-  it('can be instantiated with an object', async () => {
-    const file = new File({ name: 'foo.jpg' });
-    expect(file.name).to.equal('foo.jpg');
-  });
-});
diff --git a/test/models/hit-types/item-hit.test.ts b/test/models/hit-types/item-hit.test.ts
new file mode 100644
index 00000000..e4d34b29
--- /dev/null
+++ b/test/models/hit-types/item-hit.test.ts
@@ -0,0 +1,144 @@
+import { DateParser } from '@internetarchive/field-parsers';
+import { expect } from '@open-wc/testing';
+import { ItemHit } from '../../../src/models/hit-types/item-hit';
+import { DateField } from '../../../src/models/metadata-fields/field-types/date';
+
+describe('ItemHit', () => {
+  it('constructs basic item hit', () => {
+    const hit = new ItemHit({ fields: {} });
+    expect(hit.rawMetadata).to.deep.equal({ fields: {} });
+
+    // Small selection of fields
+    expect(hit.creator).to.be.undefined;
+    expect(hit.date).to.be.undefined;
+    expect(hit.description).to.be.undefined;
+    expect(hit.subject).to.be.undefined;
+    expect(hit.title).to.be.undefined;
+  });
+
+  it('handles incomplete data without throwing', () => {
+    const hit = new ItemHit({});
+    expect(hit.creator).to.be.undefined;
+    expect(hit.date).to.be.undefined;
+    expect(hit.description).to.be.undefined;
+    expect(hit.subject).to.be.undefined;
+    expect(hit.title).to.be.undefined;
+  });
+
+  it('constructs item hit with partial fields', () => {
+    const json = {
+      fields: {
+        identifier: 'foo',
+        title: 'foo-title',
+        description: 'foo-description',
+        subject: ['foo-subject1', 'foo-subject2'],
+        creator: ['foo-creator'],
+        collection: ['foo-collection'],
+        date: '2011-07-20T00:00:00Z',
+        year: 2011,
+        mediatype: 'movies',
+        item_size: 123456,
+        files_count: 5,
+        downloads: 123,
+        week: 2,
+        month: 15,
+        indexflag: ['index', 'nonoindex'],
+        lending___available_to_borrow: false,
+        lending___available_to_browse: false,
+        lending___available_to_waitlist: false,
+      },
+      highlight: null,
+      _score: 1,
+    };
+
+    const hit = new ItemHit(json);
+    expect(hit.rawMetadata).to.deep.equal(json);
+    expect(hit.identifier).to.equal(json.fields.identifier);
+
+    // Ensure all existing fields are present
+    for (const key of Object.keys(json.fields)) {
+      if (key === 'identifier') continue;
+      const fieldName = key as Exclude<keyof typeof json.fields, 'identifier'>;
+
+      if (Array.isArray(json.fields[fieldName])) {
+        expect(hit[fieldName]?.values).to.deep.equal(json.fields[fieldName]);
+      } else if (hit[fieldName] instanceof DateField) {
+        expect(hit[fieldName]?.value).to.deep.equal(
+          DateParser.shared.parseValue(json.fields[fieldName].toString())
+        );
+      } else {
+        expect(hit[fieldName]?.value).to.equal(json.fields[fieldName]);
+      }
+    }
+
+    expect(hit.collection_files_count?.value).to.be.undefined;
+    expect(hit.collection_size?.value).to.be.undefined;
+    expect(hit.genre?.value).to.be.undefined;
+    expect(hit.language?.value).to.be.undefined;
+    expect(hit.lending___status?.value).to.be.undefined;
+    expect(hit.licenseurl?.value).to.be.undefined;
+    expect(hit.noindex?.value).to.be.undefined;
+    expect(hit.num_favorites?.value).to.be.undefined;
+    expect(hit.num_reviews?.value).to.be.undefined;
+    expect(hit.type?.value).to.be.undefined;
+    expect(hit.volume?.value).to.be.undefined;
+  });
+
+  it('constructs item hit with all fields', () => {
+    const json = {
+      fields: {
+        identifier: 'foo',
+        title: 'foo-title',
+        description: 'foo-description',
+        subject: ['foo-subject1', 'foo-subject2'],
+        creator: ['foo-creator'],
+        collection: ['foo-collection'],
+        date: '2011-07-20T00:00:00Z',
+        year: 2011,
+        mediatype: 'movies',
+        item_size: 123456,
+        files_count: 5,
+        downloads: 123,
+        week: 2,
+        month: 15,
+        indexflag: ['index', 'nonoindex'],
+        lending___available_to_borrow: false,
+        lending___available_to_browse: false,
+        lending___available_to_waitlist: false,
+        lending___status: 'foo-status',
+        collection_files_count: 124,
+        collection_size: 125,
+        genre: 'foo-genre',
+        language: 'foo-language',
+        licenseurl: 'foo-license',
+        noindex: true,
+        num_favorites: 126,
+        num_reviews: 127,
+        type: 'foo-type',
+        volume: 'foo-volume',
+      },
+      highlight: null,
+      _score: 1,
+    };
+
+    const hit = new ItemHit(json);
+    expect(hit.rawMetadata).to.deep.equal(json);
+    expect(hit.identifier).to.equal(json.fields.identifier);
+
+    // Ensure all existing fields are present
+    for (const key of Object.keys(json.fields)) {
+      if (key === 'identifier') continue;
+      const fieldName = key as Exclude<keyof typeof json.fields, 'identifier'>;
+
+      if (Array.isArray(json.fields[fieldName])) {
+        expect(hit[fieldName]?.values).to.deep.equal(json.fields[fieldName]);
+      } else if (hit[fieldName] instanceof DateField) {
+        expect(hit[fieldName]?.value).to.deep.equal(
+          DateParser.shared.parseValue(json.fields[fieldName].toString())
+        );
+      } else {
+        expect(hit[fieldName]?.value).to.equal(json.fields[fieldName]);
+      }
+    }
+  });
+});
diff --git a/test/models/hit-types/text-hit.test.ts b/test/models/hit-types/text-hit.test.ts
new file mode 100644
index 00000000..b1492349
--- /dev/null
+++ b/test/models/hit-types/text-hit.test.ts
@@ -0,0 +1,73 @@
+import { DateParser } from '@internetarchive/field-parsers';
+import { expect } from '@open-wc/testing';
+import { TextHit } from '../../../src/models/hit-types/text-hit';
+import { DateField } from '../../../src/models/metadata-fields/field-types/date';
+
+describe('TextHit', () => {
+  it('constructs basic text hit', () => {
+    const hit = new TextHit({ fields: {} });
+    expect(hit.rawMetadata).to.deep.equal({ fields: {} });
+    expect(hit.creator).to.be.undefined;
+  });
+
+  it('handles incomplete data without throwing', () => {
+    const hit = new TextHit({});
+    expect(hit.creator).to.be.undefined;
+    expect(hit.date).to.be.undefined;
+    expect(hit.description).to.be.undefined;
+    expect(hit.subject).to.be.undefined;
+    expect(hit.title).to.be.undefined;
+  });
+
+  it('constructs text hit with all fields', () => {
+    const json = {
+      fields: {
+        identifier: 'foo',
+        mediatype: 'texts',
+        filename: 'foo-file.txt',
+        file_basename: 'foo-file',
+        file_creation_mtime: 1161893250,
+        updated_on: '2022-04-06T08:34:38Z',
+        created_on: '2016-10-09T16:51:05Z',
+        page_num: 462,
+        title: 'foo-title',
+        creator: ['foo-creator'],
+        subject: ['foo-subject1', 'foo-subject2'],
+        date: '1904-01-01T00:00:00Z',
+        publicdate: '2006-10-11T08:19:20Z',
+        downloads: 1234,
+        collection: ['foo-collection'],
+        year: 2011,
+        result_in_subfile: false,
+        description: 'foo-description',
+        __href__: '/details/foo?q=bar',
+      },
+      highlight: {
+        text: ['foo {{{bar}}} baz'],
+      },
+      _score: 1,
+    };
+
+    const hit = new TextHit(json);
+    expect(hit.rawMetadata).to.deep.equal(json);
+    expect(hit.identifier).to.equal(json.fields.identifier);
+
+    // Ensure all existing fields are present
+    for (const key of Object.keys(json.fields)) {
+      if (key === 'identifier') continue;
+      const fieldName = key as Exclude<keyof typeof json.fields, 'identifier'>;
+
+      if (Array.isArray(json.fields[fieldName])) {
+        expect(hit[fieldName]?.values).to.deep.equal(json.fields[fieldName]);
+      } else if (hit[fieldName] instanceof DateField) {
+        expect(hit[fieldName]?.value).to.deep.equal(
+          DateParser.shared.parseValue(json.fields[fieldName].toString())
+        );
+      } else {
+        expect(hit[fieldName]?.value).to.equal(json.fields[fieldName]);
+      }
+    }
+
+    expect(hit.highlight?.values).to.deep.equal(json.highlight.text);
+  });
+});
diff --git a/test/models/metadata-fields/metadata-field.test.ts b/test/models/metadata-fields/metadata-field.test.ts
index 834b00fb..c1ba3f14 100644
--- a/test/models/metadata-fields/metadata-field.test.ts
+++ b/test/models/metadata-fields/metadata-field.test.ts
@@ -1,7 +1,4 @@
-import {
-  FieldParserInterface,
-  FieldParserRawValue,
-} from '@internetarchive/field-parsers';
+import { FieldParserInterface } from '@internetarchive/field-parsers';
 import { expect } from '@open-wc/testing';
 import { MetadataField } from '../../../src/models/metadata-fields/metadata-field';
 
@@ -88,7 +85,7 @@ describe('Metadata Field', () => {
 
   it('does not add value to values array if parsed value is undefined', () => {
     class MockFloatParser implements FieldParserInterface<number> {
-      parseValue(rawValue: FieldParserRawValue): number | undefined {
+      parseValue(): number | undefined {
         return undefined;
       }
     }
diff --git a/test/responses/search-response-details.test.ts b/test/responses/search-response-details.test.ts
new file mode 100644
index 00000000..4867c1c7
--- /dev/null
+++ b/test/responses/search-response-details.test.ts
@@ -0,0 +1,79 @@
+import { expect } from '@open-wc/testing';
+import { HitType } from '../../src/models/hit-types/hit';
+import { ItemHit } from '../../src/models/hit-types/item-hit';
+import { TextHit } from '../../src/models/hit-types/text-hit';
+import { SearchResponseDetails } from '../../src/responses/search-response-details';
+
+describe('SearchResponseDetails', () => {
+  it('constructs item hits', () => {
+    const responseBody = {
+      hits: {
+        total: 2,
+        returned: 2,
+        hits: [
+          {
+            fields: {
+              identifier: 'foo',
+              mediatype: 'texts',
+            },
+          },
+          {
+            fields: {
+              identifier: 'bar',
+              collection: ['baz'],
+            },
+          },
+        ],
+      },
+    };
+
+    const responseSchema = {
+      hit_type: 'item' as HitType,
+      field_properties: {},
+    };
+
+    const details = new SearchResponseDetails(responseBody, responseSchema);
+    expect(details.results[0]).to.be.instanceOf(ItemHit);
+    expect(details.results[0].identifier).to.equal('foo');
+    expect(details.results[0].mediatype?.value).to.equal('texts');
+    expect(details.results[0].creator?.value).to.be.undefined;
+    expect(details.results[1].identifier).to.equal('bar');
+    expect(details.results[1].collection?.value).to.equal('baz');
+  });
+
+  it('constructs text hits', () => {
+    const responseBody = {
+      hits: {
+        total: 2,
+        returned: 2,
+        hits: [
+          {
+            fields: {
+              identifier: 'foo',
+              mediatype: 'texts',
+            },
+          },
+          {
+            fields: {
+              identifier: 'bar',
+              collection: ['baz'],
+            },
+          },
+        ],
+      },
+    };
+
+    const responseSchema = {
+      hit_type: 'text' as HitType,
+      field_properties: {},
+    };
+
+    const details = new SearchResponseDetails(responseBody, responseSchema);
+    expect(details.results[0]).to.be.instanceOf(TextHit);
+    expect(details.results[0].identifier).to.equal('foo');
+    expect(details.results[0].mediatype?.value).to.equal('texts');
+    expect(details.results[0].creator?.value).to.be.undefined;
+    expect(details.results[1].identifier).to.equal('bar');
+    expect(details.results[1].collection?.value).to.equal('baz');
+  });
+});
diff --git a/test/search-backend/fulltext-search-backend.test.ts b/test/search-backend/fulltext-search-backend.test.ts
new file mode 100644
index 00000000..4925f974
--- /dev/null
+++ b/test/search-backend/fulltext-search-backend.test.ts
@@ -0,0 +1,150 @@
+/* eslint-disable @typescript-eslint/no-unused-vars */
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import { expect } from '@open-wc/testing';
+import Sinon from 'sinon';
+import { FulltextSearchBackend } from '../../src/search-backend/fulltext-search-backend';
+import {
+  SearchServiceError,
+  SearchServiceErrorType,
+} from '../../src/search-service-error';
+
+describe('FulltextSearchBackend', () => {
+  describe('basic fetch behavior', () => {
+    let fetchBackup: typeof window.fetch;
+    let urlCalled: RequestInfo | URL;
+    let urlConfig: RequestInit | undefined;
+
+    beforeEach(() => {
+      fetchBackup = window.fetch;
+      urlCalled = '';
+      urlConfig = undefined;
+
+      window.fetch = (
+        url: RequestInfo | URL,
+        config?: RequestInit
+      ): Promise<Response> => {
+        urlCalled = url;
+        urlConfig = config;
+        const response = new Response('{ "foo": "bar" }');
+        return new Promise(resolve => resolve(response));
+      };
+    });
+
+    afterEach(() => {
+      window.fetch = fetchBackup;
+    });
+
+    it('can perform a search', async () => {
+      const backend = new FulltextSearchBackend();
+      const params = { query: 'foo' };
+      const result = await backend.performSearch(params);
+
+      expect(result.success?.foo).to.equal('bar');
+    });
+
+    it('sets the fts service backend', async () => {
+      const backend = new FulltextSearchBackend();
+      await backend.performSearch({ query: 'foo' });
+
+      expect(
+        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+        new URL(urlCalled!.toString()).searchParams.get('service_backend')
+      ).to.equal('fts');
+    });
+
+    it('uses the provided service path', async () => {
+      const backend = new FulltextSearchBackend({
+        baseUrl: 'foo.bar',
+        servicePath: '/baz',
+      });
+      await backend.performSearch({ query: 'boop' });
+
+      expect(urlCalled!.toString()).to.satisfy((url: string) =>
+        url.startsWith('https://foo.bar/baz')
+      );
+    });
+
+    it('includes credentials for search endpoint if requested', async () => {
+      const backend = new FulltextSearchBackend({
+        scope: 'foo',
+        includeCredentials: true,
+      });
+      await backend.performSearch({ query: 'foo' });
+
+      expect(urlConfig?.credentials).to.equal('include');
+    });
+  });
+
+  it('returns a network error result upon fetch errors', async () => {
+    const fetchBackup = window.fetch;
+    window.fetch = async () => {
+      throw new Error();
+    };
+
+    const backend = new FulltextSearchBackend();
+    const response = await backend.performSearch({ query: 'foo' });
+    expect(response).to.exist; // No error thrown
+    expect(response.error).to.be.instanceof(SearchServiceError);
+    expect(response.error?.type).to.equal(SearchServiceErrorType.networkError);
+
+    window.fetch = fetchBackup;
+  });
+
+  it('outputs debugging information if present', async () => {
+    const fetchBackup = window.fetch;
+    let urlCalled: RequestInfo | URL = '';
+    window.fetch = async (url: RequestInfo | URL) => {
+      urlCalled = url;
+      return new Response(
+        JSON.stringify({
+          debugging: {
+            debugging: {
+              messages: ['boop'],
+              data: {
+                bar: 'baz',
+              },
+            },
+          },
+        })
+      );
+    };
+
+    const logBackup = console.log;
+    const logSpy = Sinon.spy();
+    console.log = logSpy;
+
+    const backend = new FulltextSearchBackend();
+    await backend.performSearch({ query: 'foo', debugging: true });
+    expect(urlCalled).to.include('debugging=true');
+    expect(logSpy.calledWithExactly('boop')).to.be.true;
+    expect(logSpy.calledWithExactly('bar', 'baz')).to.be.true;
+
+    window.fetch = fetchBackup;
+    console.log = logBackup;
+  });
+
+  it('handles incomplete debugging information gracefully', async () => {
+    const fetchBackup = window.fetch;
+    window.fetch = async () => {
+      return new Response(
+        JSON.stringify({
+          debugging: {},
+        })
+      );
+    };
+
+    const logBackup = console.log;
+    const logSpy = Sinon.spy();
+    console.log = logSpy;
+
+    const backend = new FulltextSearchBackend();
+    const response = await backend.performSearch({
+      query: 'foo',
+      debugging: true,
+    });
+    expect(response).to.exist; // No error thrown
+
+    window.fetch = fetchBackup;
+    console.log = logBackup;
+  });
+});
diff --git a/test/search-backend/metadata-search-backend.test.ts b/test/search-backend/metadata-search-backend.test.ts
new file mode 100644
index 00000000..b0ff7496
--- /dev/null
+++ b/test/search-backend/metadata-search-backend.test.ts
@@ -0,0 +1,150 @@
+/* eslint-disable @typescript-eslint/no-unused-vars */
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import { expect } from '@open-wc/testing';
+import Sinon from 'sinon';
+import { MetadataSearchBackend } from '../../src/search-backend/metadata-search-backend';
+import {
+  SearchServiceError,
+  SearchServiceErrorType,
+} from '../../src/search-service-error';
+
+describe('MetadataSearchBackend', () => {
+  describe('basic fetch behavior', () => {
+    let fetchBackup: typeof window.fetch;
+    let urlCalled: RequestInfo | URL;
+    let urlConfig: RequestInit | undefined;
+
+    beforeEach(() => {
+      fetchBackup = window.fetch;
+      urlCalled = '';
+      urlConfig = undefined;
+
+      window.fetch = (
+        url: RequestInfo | URL,
+        config?: RequestInit
+      ): Promise<Response> => {
+        urlCalled = url;
+        urlConfig = config;
+        const response = new Response('{ "foo": "bar" }');
+        return new Promise(resolve => resolve(response));
+      };
+    });
+
+    afterEach(() => {
+      window.fetch = fetchBackup;
+    });
+
+    it('can perform a search', async () => {
+      const backend = new MetadataSearchBackend();
+      const params = { query: 'foo' };
+      const result = await backend.performSearch(params);
+
+      expect(result.success?.foo).to.equal('bar');
+    });
+
+    it('sets the metadata service backend', async () => {
+      const backend = new MetadataSearchBackend();
+      await backend.performSearch({ query: 'foo' });
+
+      expect(
+        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+        new URL(urlCalled!.toString()).searchParams.get('service_backend')
+      ).to.equal('metadata');
+    });
+
+    it('uses the provided service path', async () => {
+      const backend = new MetadataSearchBackend({
+        baseUrl: 'foo.bar',
+        servicePath: '/baz',
+      });
+      await backend.performSearch({ query: 'boop' });
+
+      expect(urlCalled!.toString()).to.satisfy((url: string) =>
+        url.startsWith('https://foo.bar/baz')
+      );
+    });
+
+    it('includes credentials for search endpoint if requested', async () => {
+      const backend = new MetadataSearchBackend({
+        scope: 'foo',
+        includeCredentials: true,
+      });
+      await backend.performSearch({ query: 'foo' });
+
+      expect(urlConfig?.credentials).to.equal('include');
+    });
+  });
+
+  it('returns a network error result upon fetch errors', async () => {
+    const fetchBackup = window.fetch;
+    window.fetch = async () => {
+      throw new Error();
+    };
+
+    const backend = new MetadataSearchBackend();
+    const response = await backend.performSearch({ query: 'foo' });
+    expect(response).to.exist; // No error thrown
+    expect(response.error).to.be.instanceof(SearchServiceError);
+    expect(response.error?.type).to.equal(SearchServiceErrorType.networkError);
+
+    window.fetch = fetchBackup;
+  });
+
+  it('outputs debugging information if present', async () => {
+    const fetchBackup = window.fetch;
+    let urlCalled: RequestInfo | URL = '';
+    window.fetch = async (url: RequestInfo | URL) => {
+      urlCalled = url;
+      return new Response(
+        JSON.stringify({
+          debugging: {
+            debugging: {
+              messages: ['boop'],
+              data: {
+                bar: 'baz',
+              },
+            },
+          },
+        })
+      );
+    };
+
+    const logBackup = console.log;
+    const logSpy = Sinon.spy();
+    console.log = logSpy;
+
+    const backend = new MetadataSearchBackend();
+    await backend.performSearch({ query: 'foo', debugging: true });
+    expect(urlCalled).to.include('debugging=true');
+    expect(logSpy.calledWithExactly('boop')).to.be.true;
+    expect(logSpy.calledWithExactly('bar', 'baz')).to.be.true;
+
+    window.fetch = fetchBackup;
+    console.log = logBackup;
+  });
+
+  it('handles incomplete debugging information gracefully', async () => {
+    const fetchBackup = window.fetch;
+    window.fetch = async () => {
+      return new Response(
+        JSON.stringify({
+          debugging: {},
+        })
+      );
+    };
+
+    const logBackup = console.log;
+    const logSpy = Sinon.spy();
+    console.log = logSpy;
+
+    const backend = new MetadataSearchBackend();
+    const response = await backend.performSearch({
+      query: 'foo',
+      debugging: true,
+    });
+    expect(response).to.exist; // No error thrown
+
+    window.fetch = fetchBackup;
+    console.log = logBackup;
+  });
+});
diff --git a/test/search-params.test.ts b/test/search-params.test.ts
index 161e9d6f..4ecc8857 100644
--- a/test/search-params.test.ts
+++ b/test/search-params.test.ts
@@ -27,7 +27,7 @@ describe('SearchParams', () => {
       params
     );
     const queryAsString = urlSearchParam.toString();
-    const expected = 'q=title%3Afoo+AND+collection%3Abar&output=json';
+    const expected = 'user_query=title%3Afoo+AND+collection%3Abar';
     expect(queryAsString).to.equal(expected);
   });
 
@@ -43,7 +43,7 @@ describe('SearchParams', () => {
     );
     const queryAsString = urlSearchParam.toString();
     const expected =
-      'q=title%3Afoo+AND+collection%3Abar&output=json&fl=identifier%2Cfoo%2Cbar';
+      'user_query=title%3Afoo+AND+collection%3Abar&fields=identifier%2Cfoo%2Cbar';
     expect(queryAsString).to.equal(expected);
   });
 
@@ -63,7 +63,7 @@ describe('SearchParams', () => {
     );
     const queryAsString = urlSearchParam.toString();
     const expected =
-      'q=title%3Afoo+AND+collection%3Abar&output=json&rows=53&page=27&fl=identifier%2Cfoo%2Cbar&sort=downloads+desc';
+      'user_query=title%3Afoo+AND+collection%3Abar&hits_per_page=53&page=27&fields=identifier%2Cfoo%2Cbar&sort=downloads%3Adesc';
     expect(queryAsString).to.equal(expected);
   });
 
@@ -84,7 +84,55 @@ describe('SearchParams', () => {
     );
     const queryAsString = urlSearchParam.toString();
     const expected =
-      'q=title%3Afoo+AND+collection%3Abar&output=json&rows=53&page=27&sort=downloads+desc%2Cfoo+asc';
+      'user_query=title%3Afoo+AND+collection%3Abar&hits_per_page=53&page=27&sort=downloads%3Adesc%2Cfoo%3Aasc';
+    expect(queryAsString).to.equal(expected);
+  });
+
+  it('properly generates a URLSearchParam with a page_type', async () => {
+    const query = 'title:foo AND collection:bar';
+    const params = {
+      query,
+      pageType: 'foo',
+    };
+    const urlSearchParam = SearchParamURLGenerator.generateURLSearchParams(
+      params
+    );
+    const queryAsString = urlSearchParam.toString();
+    const expected =
+      'user_query=title%3Afoo+AND+collection%3Abar&page_type=foo';
+    expect(queryAsString).to.equal(expected);
+  });
+
+  it('properly generates a URLSearchParam with a page_type and page_target', async () => {
+    const query = 'title:foo AND collection:bar';
+    const params = {
+      query,
+      pageType: 'foo',
+      pageTarget: 'bar',
+    };
+    const urlSearchParam = SearchParamURLGenerator.generateURLSearchParams(
+      params
+    );
+    const queryAsString = urlSearchParam.toString();
+    const expected =
+      'user_query=title%3Afoo+AND+collection%3Abar&page_type=foo&page_target=bar';
+    expect(queryAsString).to.equal(expected);
+  });
+
+  it('properly generates a URLSearchParam with aggregations omitted', async () => {
+    const query = 'title:foo AND collection:bar';
+    const params = {
+      query,
+      aggregations: {
+        omit: true,
+      },
+    };
+    const urlSearchParam = SearchParamURLGenerator.generateURLSearchParams(
+      params
+    );
+    const queryAsString = urlSearchParam.toString();
+    const expected =
+      'user_query=title%3Afoo+AND+collection%3Abar&aggregations=false';
     expect(queryAsString).to.equal(expected);
   });
 
@@ -111,7 +159,7 @@ describe('SearchParams', () => {
     );
     const queryAsString = urlSearchParam.toString();
     const expected =
-      'q=title%3Afoo+AND+collection%3Abar&output=json&user_aggs=%5B%7B%22terms%22%3A%7B%22field%22%3A%22foo%22%2C%22size%22%3A10%7D%7D%2C%7B%22terms%22%3A%7B%22field%22%3A%22bar%22%2C%22size%22%3A7%7D%7D%5D';
+      'user_query=title%3Afoo+AND+collection%3Abar&aggregations=%5B%7B%22terms%22%3A%7B%22field%22%3A%22foo%22%2C%22size%22%3A10%7D%7D%2C%7B%22terms%22%3A%7B%22field%22%3A%22bar%22%2C%22size%22%3A7%7D%7D%5D';
     expect(queryAsString).to.equal(expected);
   });
 
@@ -129,7 +177,26 @@ describe('SearchParams', () => {
     );
     const queryAsString = urlSearchParam.toString();
     const expected =
-      'q=title%3Afoo+AND+collection%3Abar&output=json&user_aggs=year%2Ccollection%2Csubject';
+      'user_query=title%3Afoo+AND+collection%3Abar&aggregations=year%2Ccollection%2Csubject';
+    expect(queryAsString).to.equal(expected);
+  });
+
+  it('properly generates a URLSearchParam with an aggregations_size param', async () => {
+    const query = 'title:foo AND collection:bar';
+    const aggregations = {
+      simpleParams: ['year', 'collection', 'subject'],
+    };
+    const params = {
+      query,
+      aggregations,
+      aggregationsSize: 3,
+    };
+    const urlSearchParam = SearchParamURLGenerator.generateURLSearchParams(
+      params
+    );
+    const queryAsString = urlSearchParam.toString();
+    const expected =
+      'user_query=title%3Afoo+AND+collection%3Abar&aggregations=year%2Ccollection%2Csubject&aggregations_size=3';
     expect(queryAsString).to.equal(expected);
   });
 
@@ -157,7 +224,7 @@ describe('SearchParams', () => {
     );
     const queryAsString = urlSearchParam.toString();
     const expected =
-      'q=title%3Afoo+AND+collection%3Abar&output=json&user_aggs=%5B%7B%22terms%22%3A%7B%22field%22%3A%22foo%22%2C%22size%22%3A10%7D%7D%2C%7B%22terms%22%3A%7B%22field%22%3A%22bar%22%2C%22size%22%3A7%7D%7D%5D';
+      'user_query=title%3Afoo+AND+collection%3Abar&aggregations=%5B%7B%22terms%22%3A%7B%22field%22%3A%22foo%22%2C%22size%22%3A10%7D%7D%2C%7B%22terms%22%3A%7B%22field%22%3A%22bar%22%2C%22size%22%3A7%7D%7D%5D';
     expect(queryAsString).to.equal(expected);
   });
 });
diff --git a/test/search-service.test.ts b/test/search-service.test.ts
index 41c78de9..3c3b5e5e 100644
--- a/test/search-service.test.ts
+++ b/test/search-service.test.ts
@@ -1,159 +1,54 @@
 /* eslint-disable @typescript-eslint/no-unused-vars */
 /* eslint-disable @typescript-eslint/no-explicit-any */
 import { expect } from '@open-wc/testing';
-
+import sinon from 'sinon';
 import { SearchService } from '../src/search-service';
 import { SearchParams } from '../src/search-params';
 
 import { MockResponseGenerator } from './mock-response-generator';
-import { SearchResponse } from '../src/responses/search/search-response';
-import { MetadataResponse } from '../src/responses/metadata/metadata-response';
 import { Result } from '@internetarchive/result-type';
 import {
   SearchServiceError,
   SearchServiceErrorType,
 } from '../src/search-service-error';
 import { SearchBackendInterface } from '../src/search-backend/search-backend-interface';
+import { SearchType } from '../src/search-type';
+import { MetadataSearchBackend } from '../src/search-backend/metadata-search-backend';
+import { FulltextSearchBackend } from '../src/search-backend/fulltext-search-backend';
 
 describe('SearchService', () => {
   it('can search when requested', async () => {
     class MockSearchBackend implements SearchBackendInterface {
-      async fetchMetadata(
-        identifier: string
-      ): Promise<Result<MetadataResponse, SearchServiceError>> {
-        throw new Error('Method not implemented.');
-      }
-
       async performSearch(
         params: SearchParams
-      ): Promise<Result<SearchResponse, SearchServiceError>> {
+      ): Promise<Result<any, SearchServiceError>> {
         const responseGenerator = new MockResponseGenerator();
-        const mockResponse = responseGenerator.generateMockSearchResponse(
+        const mockResponse = responseGenerator.generateMockMetadataSearchResponse(
           params
         );
         return { success: mockResponse };
       }
     }
 
-    const query = 'title:foo AND collection:bar';
-    const backend = new MockSearchBackend();
-    const service = new SearchService(backend);
-    const result = await service.search({ query });
-    expect(result.success?.responseHeader.params.query).to.equal(query);
-  });
-
-  it('can request metadata when requested', async () => {
-    class MockSearchBackend implements SearchBackendInterface {
-      performSearch(
-        params: SearchParams
-      ): Promise<Result<SearchResponse, SearchServiceError>> {
-        throw new Error('Method not implemented.');
-      }
-      async fetchMetadata(
-        identifier: string
-      ): Promise<Result<MetadataResponse, SearchServiceError>> {
-        const responseGenerator = new MockResponseGenerator();
-        const mockResponse = responseGenerator.generateMockMetadataResponse(
-          identifier
-        );
-        return { success: mockResponse };
-      }
-    }
-
     const backend = new MockSearchBackend();
-    const service = new SearchService(backend);
-    const result = await service.fetchMetadata('foo');
-    expect(result.success?.metadata.identifier).to.equal('foo');
-  });
+    const realFactoryMethod = SearchService.getBackendForSearchType;
+    SearchService.getBackendForSearchType = () => backend;
 
-  describe('requestMetadataValue', async () => {
-    class MockSearchBackend implements SearchBackendInterface {
-      response: any;
-      performSearch(
-        params: SearchParams
-      ): Promise<Result<SearchResponse, SearchServiceError>> {
-        throw new Error('Method not implemented.');
-      }
-      async fetchMetadata(
-        identifier: string,
-        keypath?: string
-      ): Promise<Result<any, SearchServiceError>> {
-        return {
-          success: {
-            result: this.response,
-          },
-        };
-      }
-    }
-
-    it('can request a metadata value', async () => {
-      const backend = new MockSearchBackend();
-      const service = new SearchService(backend);
-
-      let expectedResult: any = 'foo';
-      backend.response = expectedResult;
-
-      let result = await service.fetchMetadataValue<typeof expectedResult>(
-        'foo',
-        'metadata'
-      );
-      expect(result.success).to.equal(expectedResult);
-
-      expectedResult = { foo: 'bar' };
-      backend.response = expectedResult;
-
-      result = await service.fetchMetadataValue<typeof expectedResult>(
-        'foo',
-        'metadata'
-      );
-      expect(result.success).to.equal(expectedResult);
-      expect(result.success.foo).to.equal('bar');
-    });
-  });
-
-  it('returns an error result if the item is not found', async () => {
-    class MockSearchBackend implements SearchBackendInterface {
-      performSearch(
-        params: SearchParams
-      ): Promise<Result<SearchResponse, SearchServiceError>> {
-        throw new Error('Method not implemented.');
-      }
-      async fetchMetadata(
-        identifier: string
-      ): Promise<Result<MetadataResponse, SearchServiceError>> {
-        // this is unfortunate.. instead of getting an http 404 error,
-        // we get an empty JSON object when an item is not found
-        return { success: {} as any };
-      }
-    }
-
-    const backend = new MockSearchBackend();
-    const service = new SearchService(backend);
-    const result = await service.fetchMetadata('foo');
-    expect(result.error).to.not.equal(undefined);
-    expect(result.error?.type).to.equal(SearchServiceErrorType.itemNotFound);
-
-    const valueResult = await service.fetchMetadataValue('foo', 'metadata');
-    expect(valueResult.error).to.not.equal(undefined);
-    expect(valueResult.error?.type).to.equal(
-      SearchServiceErrorType.itemNotFound
+    const query = 'title:foo AND collection:bar';
+    const service = new SearchService();
+    const result = await service.search({ query });
+    expect(result.success?.request.finalizedParameters.user_query).to.equal(
+      query
     );
+
+    SearchService.getBackendForSearchType = realFactoryMethod;
   });
 
   it('returns the search backend network error if one occurs', async () => {
     class MockSearchBackend implements SearchBackendInterface {
       async performSearch(
         params: SearchParams
-      ): Promise<Result<SearchResponse, SearchServiceError>> {
-        const error = new SearchServiceError(
-          SearchServiceErrorType.networkError,
-          'network error'
-        );
-        return { error };
-      }
-      async fetchMetadata(
-        identifier: string
-      ): Promise<Result<MetadataResponse, SearchServiceError>> {
+      ): Promise<Result<any, SearchServiceError>> {
         const error = new SearchServiceError(
           SearchServiceErrorType.networkError,
           'network error'
@@ -163,20 +58,10 @@ describe('SearchService', () => {
     }
 
     const backend = new MockSearchBackend();
-    const service = new SearchService(backend);
-    const metadataResult = await service.fetchMetadata('foo');
-    expect(metadataResult.error).to.not.equal(undefined);
-    expect(metadataResult.error?.type).to.equal(
-      SearchServiceErrorType.networkError
-    );
-    expect(metadataResult.error?.message).to.equal('network error');
+    const realFactoryMethod = SearchService.getBackendForSearchType;
+    SearchService.getBackendForSearchType = () => backend;
 
-    const metadataValueResult = await service.fetchMetadataValue('foo', 'bar');
-    expect(metadataValueResult.error).to.not.equal(undefined);
-    expect(metadataValueResult.error?.type).to.equal(
-      SearchServiceErrorType.networkError
-    );
-    expect(metadataValueResult.error?.message).to.equal('network error');
+    const service = new SearchService();
 
     const searchResult = await service.search({ query: 'boop' });
     expect(searchResult.error).to.not.equal(undefined);
@@ -184,22 +69,15 @@ describe('SearchService', () => {
       SearchServiceErrorType.networkError
     );
     expect(searchResult.error?.message).to.equal('network error');
+
+    SearchService.getBackendForSearchType = realFactoryMethod;
   });
 
   it('returns the search backend decoding error if one occurs', async () => {
     class MockSearchBackend implements SearchBackendInterface {
       async performSearch(
         params: SearchParams
-      ): Promise<Result<SearchResponse, SearchServiceError>> {
-        const error = new SearchServiceError(
-          SearchServiceErrorType.decodingError,
-          'decoding error'
-        );
-        return { error };
-      }
-      async fetchMetadata(
-        identifier: string
-      ): Promise<Result<MetadataResponse, SearchServiceError>> {
+      ): Promise<Result<any, SearchServiceError>> {
         const error = new SearchServiceError(
           SearchServiceErrorType.decodingError,
           'decoding error'
@@ -209,13 +87,10 @@ describe('SearchService', () => {
     }
 
     const backend = new MockSearchBackend();
-    const service = new SearchService(backend);
-    const metadataResult = await service.fetchMetadata('foo');
-    expect(metadataResult.error).to.not.equal(undefined);
-    expect(metadataResult.error?.type).to.equal(
-      SearchServiceErrorType.decodingError
-    );
-    expect(metadataResult.error?.message).to.equal('decoding error');
+    const realFactoryMethod = SearchService.getBackendForSearchType;
+    SearchService.getBackendForSearchType = () => backend;
+
+    const service = new SearchService();
 
     const searchResult = await service.search({ query: 'boop' });
     expect(searchResult.error).to.not.equal(undefined);
@@ -223,5 +98,58 @@ describe('SearchService', () => {
       SearchServiceErrorType.decodingError
     );
     expect(searchResult.error?.message).to.equal('decoding error');
+
+    SearchService.getBackendForSearchType = realFactoryMethod;
+  });
+
+  it('passes backend options to backend', async () => {
+    class MockSearchBackend implements SearchBackendInterface {
+      async performSearch(
+        params: SearchParams
+      ): Promise<Result<any, SearchServiceError>> {
+        const responseGenerator = new MockResponseGenerator();
+        const mockResponse = responseGenerator.generateMockMetadataSearchResponse(
+          params
+        );
+        return { success: mockResponse };
+      }
+    }
+
+    const backend = new MockSearchBackend();
+    const spy = sinon.spy();
+
+    const realFactoryMethod = SearchService.getBackendForSearchType;
+    SearchService.getBackendForSearchType = (...args) => {
+      spy(...args);
+      return backend;
+    };
+
+    const backendOptions = {
+      baseUrl: 'foo.bar',
+      includeCredentials: true,
+      scope: 'baz',
+    };
+
+    const service = new SearchService(backendOptions);
+
+    const params = { query: 'boop' };
+    await service.search(params);
+
+    expect(spy.callCount).to.equal(1);
+    expect(spy.calledWithExactly(params, backendOptions));
+
+    SearchService.getBackendForSearchType = realFactoryMethod;
+  });
+
+  it('factory method gets metadata backend', async () => {
+    expect(
+      SearchService.getBackendForSearchType(SearchType.METADATA)
+    ).to.be.instanceOf(MetadataSearchBackend);
+  });
+
+  it('factory method gets fulltext backend', async () => {
+    expect(
+      SearchService.getBackendForSearchType(SearchType.FULLTEXT)
+    ).to.be.instanceOf(FulltextSearchBackend);
   });
 });
diff --git a/tsconfig.json b/tsconfig.json
index 5736b1d5..70cf89bf 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -4,7 +4,7 @@
     "module": "esnext",
     "moduleResolution": "node",
     "noEmitOnError": true,
-    "lib": ["es2017", "dom"],
+    "lib": ["es2017", "dom", "dom.iterable"],
     "strict": true,
     "esModuleInterop": false,
     "allowSyntheticDefaultImports": true,