diff --git a/packages/react-router/src/Scripts.tsx b/packages/react-router/src/Scripts.tsx
index 28c05bf2749..96f700eff78 100644
--- a/packages/react-router/src/Scripts.tsx
+++ b/packages/react-router/src/Scripts.tsx
@@ -3,6 +3,10 @@ import { useRouterState } from './useRouterState'
 import { useRouter } from './useRouter'
 import type { RouterManagedTag } from '@tanstack/router-core'
 
+/**
+ * Render body script tags collected from route matches and SSR manifests.
+ * Should be placed near the end of the document body.
+ */
 export const Scripts = () => {
   const router = useRouter()
   const nonce = router.options.ssr?.nonce
diff --git a/packages/react-router/src/ScrollRestoration.tsx b/packages/react-router/src/ScrollRestoration.tsx
index 71d472723de..55591c92cee 100644
--- a/packages/react-router/src/ScrollRestoration.tsx
+++ b/packages/react-router/src/ScrollRestoration.tsx
@@ -17,7 +17,7 @@ function useScrollRestoration() {
 }
 
 /**
- * @deprecated use createRouter's `scrollRestoration` option instead
+ * @deprecated Use the `scrollRestoration` router option instead.
  */
 export function ScrollRestoration(_props: ScrollRestorationOptions) {
   useScrollRestoration()
diff --git a/packages/react-router/src/awaited.tsx b/packages/react-router/src/awaited.tsx
index f695b33e8c5..d177288781d 100644
--- a/packages/react-router/src/awaited.tsx
+++ b/packages/react-router/src/awaited.tsx
@@ -7,6 +7,7 @@ export type AwaitOptions<T> = {
   promise: Promise<T>
 }
 
+/** Suspend until a deferred promise resolves/rejects and return its data. */
 export function useAwaited<T>({
   promise: _promise,
 }: AwaitOptions<T>): [T, DeferredPromise<T>] {
@@ -23,6 +24,10 @@ export function useAwaited<T>({
   return [promise[TSR_DEFERRED_PROMISE].data, promise]
 }
 
+/**
+ * Component that suspends on a deferred promise and renders its child with
+ * the resolved value. Optionally provides a Suspense fallback.
+ */
 export function Await<T>(
   props: AwaitOptions<T> & {
     fallback?: React.ReactNode
diff --git a/packages/react-router/src/route.tsx b/packages/react-router/src/route.tsx
index 0aefd3673eb..3fb7716e7a5 100644
--- a/packages/react-router/src/route.tsx
+++ b/packages/react-router/src/route.tsx
@@ -78,24 +78,6 @@ declare module '@tanstack/router-core' {
   }
 }
 
-/**
- * Returns a route-specific API that exposes type-safe hooks pre-bound
- * to a single route ID. Useful for consuming a route's APIs from files
- * where the route object isn't directly imported (e.g. code-split files).
- *
- * @param id Route ID string literal for the target route.
- * @returns A `RouteApi` instance bound to the given route ID.
- * @link https://tanstack.com/router/latest/docs/framework/react/api/router/getRouteApiFunction
- */
-/**
- * Returns a route-specific API that exposes type-safe hooks pre-bound
- * to a single route ID. Useful for consuming a route's APIs from files
- * where the route object isn't directly imported (e.g. code-split files).
- *
- * @param id Route ID string literal for the target route.
- * @returns A `RouteApi` instance bound to the given route ID.
- * @link https://tanstack.com/router/latest/docs/framework/react/api/router/getRouteApiFunction
- */
 /**
  * Returns a route-specific API that exposes type-safe hooks pre-bound
  * to a single route ID. Useful for consuming a route's APIs from files
diff --git a/packages/react-router/src/useRouter.tsx b/packages/react-router/src/useRouter.tsx
index 1eadfb68b5a..abfefecaa3e 100644
--- a/packages/react-router/src/useRouter.tsx
+++ b/packages/react-router/src/useRouter.tsx
@@ -3,16 +3,6 @@ import warning from 'tiny-warning'
 import { getRouterContext } from './routerContext'
 import type { AnyRouter, RegisteredRouter } from '@tanstack/router-core'
 
-/**
- * Access the current TanStack Router instance from React context.
- * Must be used within a `RouterProvider`.
- *
- * Options:
- * - `warn`: Log a warning if no router context is found (default: true).
- *
- * @returns The registered router instance.
- * @link https://tanstack.com/router/latest/docs/framework/react/api/router/useRouterHook
- */
 /**
  * Access the current TanStack Router instance from React context.
  * Must be used within a `RouterProvider`.
diff --git a/packages/router-core/src/path.ts b/packages/router-core/src/path.ts
index 1c3b6341cf3..edb5a8d22cb 100644
--- a/packages/router-core/src/path.ts
+++ b/packages/router-core/src/path.ts
@@ -22,6 +22,7 @@ export interface Segment {
   readonly hasStaticAfter?: boolean
 }
 
+/** Join path segments, cleaning duplicate slashes between parts. */
 export function joinPaths(paths: Array<string | undefined>) {
   return cleanPath(
     paths
@@ -32,23 +33,28 @@ export function joinPaths(paths: Array<string | undefined>) {
   )
 }
 
+/** Remove repeated slashes from a path string. */
 export function cleanPath(path: string) {
   // remove double slashes
   return path.replace(/\/{2,}/g, '/')
 }
 
+/** Trim leading slashes (except preserving root '/'). */
 export function trimPathLeft(path: string) {
   return path === '/' ? path : path.replace(/^\/{1,}/, '')
 }
 
+/** Trim trailing slashes (except preserving root '/'). */
 export function trimPathRight(path: string) {
   return path === '/' ? path : path.replace(/\/{1,}$/, '')
 }
 
+/** Trim both leading and trailing slashes. */
 export function trimPath(path: string) {
   return trimPathRight(trimPathLeft(path))
 }
 
+/** Remove a trailing slash from value when appropriate for comparisons. */
 export function removeTrailingSlash(value: string, basepath: string): string {
   if (value?.endsWith('/') && value !== '/' && value !== `${basepath}/`) {
     return value.slice(0, -1)
@@ -149,6 +155,10 @@ function segmentToString(segment: Segment): string {
   return value
 }
 
+/**
+ * Resolve a destination path against a base, honoring trailing-slash policy
+ * and supporting relative segments (`.`/`..`) and absolute `to` values.
+ */
 export function resolvePath({
   base,
   to,
@@ -384,6 +394,13 @@ type InterPolatePathResult = {
   usedParams: Record<string, unknown>
   isMissingParams: boolean // true if any params were not available when being looked up in the params object
 }
+/**
+ * Interpolate params and wildcards into a route path template.
+ *
+ * - Encodes params safely (configurable allowed characters)
+ * - Supports `{-$optional}` segments, `{prefix{$id}suffix}` and `{$}` wildcards
+ * - Optionally leaves placeholders or wildcards in place
+ */
 export function interpolatePath({
   path,
   params,
@@ -510,6 +527,10 @@ function encodePathParam(value: string, decodeCharMap?: Map<string, string>) {
   return encoded
 }
 
+/**
+ * Match a pathname against a route destination and return extracted params
+ * or `undefined`. Uses the same parsing as the router for consistency.
+ */
 export function matchPathname(
   currentPathname: string,
   matchLocation: Pick<MatchLocation, 'to' | 'fuzzy' | 'caseSensitive'>,
@@ -525,6 +546,7 @@ export function matchPathname(
   return pathParams ?? {}
 }
 
+/** Low-level matcher that compares two path strings and extracts params. */
 export function matchByPath(
   from: string,
   {
diff --git a/packages/router-core/src/qss.ts b/packages/router-core/src/qss.ts
index 550a5b0cea5..15b7728dd35 100644
--- a/packages/router-core/src/qss.ts
+++ b/packages/router-core/src/qss.ts
@@ -22,6 +22,7 @@
  * // Expected output: "token=foo&key=value"
  * ```
  */
+/** Encode a plain object into a URL query string using URLSearchParams. */
 export function encode(
   obj: Record<string, any>,
   stringify: (value: any) => string = String,
@@ -62,6 +63,7 @@ function toValue(str: unknown) {
  * // Example input: decode("token=foo&key=value")
  * // Expected output: { "token": "foo", "key": "value" }
  */
+/** Decode a URL query string into an object with basic type coercion. */
 export function decode(str: any): any {
   const searchParams = new URLSearchParams(str)
 
diff --git a/packages/router-core/src/redirect.ts b/packages/router-core/src/redirect.ts
index 277d184b4b2..4672bf3febf 100644
--- a/packages/router-core/src/redirect.ts
+++ b/packages/router-core/src/redirect.ts
@@ -114,12 +114,14 @@ export function isRedirect(obj: any): obj is AnyRedirect {
   return obj instanceof Response && !!(obj as any).options
 }
 
+/** True if value is a redirect with a resolved `href` location. */
 export function isResolvedRedirect(
   obj: any,
 ): obj is AnyRedirect & { options: { href: string } } {
   return isRedirect(obj) && !!obj.options.href
 }
 
+/** Parse a serialized redirect object back into a redirect Response. */
 export function parseRedirect(obj: any) {
   if (obj !== null && typeof obj === 'object' && obj.isSerializedRedirect) {
     return redirect(obj)
diff --git a/packages/router-core/src/rewrite.ts b/packages/router-core/src/rewrite.ts
index 7ffb49b8e15..452bf98b13d 100644
--- a/packages/router-core/src/rewrite.ts
+++ b/packages/router-core/src/rewrite.ts
@@ -1,6 +1,7 @@
 import { joinPaths, trimPath } from './path'
 import type { LocationRewrite } from './router'
 
+/** Compose multiple rewrite pairs into a single in/out rewrite. */
 export function composeRewrites(rewrites: Array<LocationRewrite>) {
   return {
     input: ({ url }) => {
@@ -18,6 +19,7 @@ export function composeRewrites(rewrites: Array<LocationRewrite>) {
   } satisfies LocationRewrite
 }
 
+/** Create a rewrite pair that strips/adds a basepath on input/output. */
 export function rewriteBasepath(opts: {
   basepath: string
   caseSensitive?: boolean
@@ -54,6 +56,7 @@ export function rewriteBasepath(opts: {
   } satisfies LocationRewrite
 }
 
+/** Execute a location input rewrite if provided. */
 export function executeRewriteInput(
   rewrite: LocationRewrite | undefined,
   url: URL,
@@ -69,6 +72,7 @@ export function executeRewriteInput(
   return url
 }
 
+/** Execute a location output rewrite if provided. */
 export function executeRewriteOutput(
   rewrite: LocationRewrite | undefined,
   url: URL,
diff --git a/packages/router-core/src/router.ts b/packages/router-core/src/router.ts
index df01f7a8356..9ff9eb3dca6 100644
--- a/packages/router-core/src/router.ts
+++ b/packages/router-core/src/router.ts
@@ -842,6 +842,15 @@ export type CreateRouterFn = <
   TDehydrated
 >
 
+/**
+ * Core, framework-agnostic router engine that powers TanStack Router.
+ *
+ * Provides navigation, matching, loading, preloading, caching and event APIs
+ * used by framework adapters (React/Solid). Prefer framework helpers like
+ * `createRouter` in app code.
+ *
+ * @link https://tanstack.com/router/latest/docs/framework/react/api/router/RouterType
+ */
 export class RouterCore<
   in out TRouteTree extends AnyRoute,
   in out TTrailingSlashOption extends TrailingSlashOption,
@@ -1096,6 +1105,12 @@ export class RouterCore<
     }
   }
 
+  /**
+   * Subscribe to router lifecycle events like `onBeforeNavigate`, `onLoad`,
+   * `onResolved`, etc. Returns an unsubscribe function.
+   *
+   * @link https://tanstack.com/router/latest/docs/framework/react/api/router/RouterEventsType
+   */
   subscribe: SubscribeFn = (eventType, fn) => {
     const listener: RouterListener<any> = {
       eventType,
@@ -1117,6 +1132,10 @@ export class RouterCore<
     })
   }
 
+  /**
+   * Parse a HistoryLocation into a strongly-typed ParsedLocation using the
+   * current router options, rewrite rules and search parser/stringifier.
+   */
   parseLocation: ParseLocationFn<TRouteTree> = (
     locationToParse,
     previousLocation,
@@ -1172,6 +1191,7 @@ export class RouterCore<
     return location
   }
 
+  /** Resolve a path against the router basepath and trailing-slash policy. */
   resolvePathWithBase = (from: string, path: string) => {
     const resolvedPath = resolvePath({
       base: from,
@@ -1538,6 +1558,13 @@ export class RouterCore<
     })
   }
 
+  /**
+   * Build the next ParsedLocation from navigation options without committing.
+   * Resolves `to`/`from`, params/search/hash/state, applies search validation
+   * and middlewares, and returns a stable, stringified location object.
+   *
+   * @link https://tanstack.com/router/latest/docs/framework/react/api/router/RouterType#buildlocation-method
+   */
   buildLocation: BuildLocationFn = (opts) => {
     const build = (
       dest: BuildNextOptions & {
@@ -1785,6 +1812,10 @@ export class RouterCore<
 
   commitLocationPromise: undefined | ControlledPromise<void>
 
+  /**
+   * Commit a previously built location to history (push/replace), optionally
+   * using view transitions and scroll restoration options.
+   */
   commitLocation: CommitLocationFn = ({
     viewTransition,
     ignoreBlocker,
@@ -1875,6 +1906,7 @@ export class RouterCore<
     return this.commitLocationPromise
   }
 
+  /** Convenience helper: build a location from options, then commit it. */
   buildAndCommitLocation = ({
     replace,
     resetScroll,
@@ -1911,6 +1943,13 @@ export class RouterCore<
     })
   }
 
+  /**
+   * Imperatively navigate using standard `NavigateOptions`. When `reloadDocument`
+   * or an absolute `href` is provided, performs a full document navigation.
+   * Otherwise, builds and commits a client-side location.
+   *
+   * @link https://tanstack.com/router/latest/docs/framework/react/api/router/NavigateOptionsType
+   */
   navigate: NavigateFn = ({ to, reloadDocument, href, ...rest }) => {
     if (!reloadDocument && href) {
       try {
diff --git a/packages/router-core/src/scroll-restoration.ts b/packages/router-core/src/scroll-restoration.ts
index d662a654b80..cc6432221ce 100644
--- a/packages/router-core/src/scroll-restoration.ts
+++ b/packages/router-core/src/scroll-restoration.ts
@@ -33,6 +33,7 @@ function getSafeSessionStorage() {
   return undefined
 }
 
+/** SessionStorage key used to persist scroll restoration state. */
 export const storageKey = 'tsr-scroll-restoration-v1_3'
 
 const throttle = (fn: (...args: Array<any>) => void, wait: number) => {
@@ -70,6 +71,7 @@ function createScrollRestorationCache(): ScrollRestorationCache | null {
   }
 }
 
+/** In-memory handle to the persisted scroll restoration cache. */
 export const scrollRestorationCache = createScrollRestorationCache()
 
 /**
@@ -79,10 +81,14 @@ export const scrollRestorationCache = createScrollRestorationCache()
  * The `location.href` is used as a fallback to support the use case where the location state is not available like the initial render.
  */
 
+/**
+ * Default scroll restoration cache key: location state key or full href.
+ */
 export const defaultGetScrollRestorationKey = (location: ParsedLocation) => {
   return location.state.__TSR_key! || location.href
 }
 
+/** Best-effort nth-child CSS selector for a given element. */
 export function getCssSelector(el: any): string {
   const path = []
   let parent: HTMLElement
@@ -101,6 +107,9 @@ let ignoreScroll = false
 // unless they are passed in as arguments. Why? Because we need to be able to
 // toString() it into a script tag to execute as early as possible in the browser
 // during SSR. Additionally, we also call it from within the router lifecycle
+/**
+ * Restore scroll positions for window/elements based on cached entries.
+ */
 export function restoreScroll({
   storageKey,
   key,
@@ -200,6 +209,7 @@ export function restoreScroll({
   ignoreScroll = false
 }
 
+/** Setup global listeners and hooks to support scroll restoration. */
 export function setupScrollRestoration(router: AnyRouter, force?: boolean) {
   if (!scrollRestorationCache && !router.isServer) {
     return
@@ -357,6 +367,14 @@ export function setupScrollRestoration(router: AnyRouter, force?: boolean) {
   })
 }
 
+/**
+ * @private
+ * Handles hash-based scrolling after navigation completes.
+ * To be used in framework-specific <Transitioner> components during the onResolved event.
+ *
+ * Provides hash scrolling for programmatic navigation when default browser handling is prevented.
+ * @param router The router instance containing current location and state
+ */
 /**
  * @private
  * Handles hash-based scrolling after navigation completes.
diff --git a/packages/router-core/src/searchMiddleware.ts b/packages/router-core/src/searchMiddleware.ts
index e90d453350f..32d672348ea 100644
--- a/packages/router-core/src/searchMiddleware.ts
+++ b/packages/router-core/src/searchMiddleware.ts
@@ -13,6 +13,9 @@ import type { IsRequiredParams } from './link'
  * @returns A search middleware suitable for route `search.middlewares`.
  * @link https://tanstack.com/router/latest/docs/framework/react/api/router/retainSearchParamsFunction
  */
+/**
+ * Retain specified search params across navigations by merging prior values.
+ */
 export function retainSearchParams<TSearchSchema extends object>(
   keys: Array<keyof TSearchSchema> | true,
 ): SearchMiddleware<TSearchSchema> {
@@ -41,6 +44,9 @@ export function retainSearchParams<TSearchSchema extends object>(
  * @returns A search middleware suitable for route `search.middlewares`.
  * @link https://tanstack.com/router/latest/docs/framework/react/api/router/stripSearchParamsFunction
  */
+/**
+ * Remove optional/default-valued search params from navigations.
+ */
 export function stripSearchParams<
   TSearchSchema,
   TOptionalProps = PickOptional<NoInfer<TSearchSchema>>,
diff --git a/packages/router-core/src/searchParams.ts b/packages/router-core/src/searchParams.ts
index f36d8e490a6..f8b9205bebf 100644
--- a/packages/router-core/src/searchParams.ts
+++ b/packages/router-core/src/searchParams.ts
@@ -1,6 +1,7 @@
 import { decode, encode } from './qss'
 import type { AnySchema } from './validators'
 
+/** Default `parseSearch` that strips leading '?' and JSON-parses values. */
 export const defaultParseSearch = parseSearchWith(JSON.parse)
 export const defaultStringifySearch = stringifySearchWith(
   JSON.stringify,
@@ -17,6 +18,7 @@ export const defaultStringifySearch = stringifySearchWith(
  * @returns A `parseSearch` function compatible with `Router` options.
  * @link https://tanstack.com/router/latest/docs/framework/react/guide/custom-search-param-serialization
  */
+/** Build a parseSearch function using a provided JSON-like parser. */
 export function parseSearchWith(parser: (str: string) => any) {
   return (searchStr: string): AnySchema => {
     if (searchStr[0] === '?') {
@@ -53,6 +55,7 @@ export function parseSearchWith(parser: (str: string) => any) {
  * @returns A `stringifySearch` function compatible with `Router` options.
  * @link https://tanstack.com/router/latest/docs/framework/react/guide/custom-search-param-serialization
  */
+/** Build a stringifySearch function using a provided serializer/parser. */
 export function stringifySearchWith(
   stringify: (search: any) => string,
   parser?: (str: string) => any,