🥞 Flapjack

Self-hosted search engine with an Algolia-compatible API. Single binary, no dependencies.

Drop-in replacement for Algolia — works with InstantSearch.js and the algoliasearch client. Typo-tolerant full-text search with faceting, geo search, and custom ranking. Single static binary, runs anywhere, data stays on disk.

Live Demo · Geo Demo · API Docs

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Quickstart

curl -fsSL https://install.flapjack.foo | sh    #install

flapjack                                        #run the server

open http://127.0.0.1:7700/dashboard            #load the dashboard


# Add documents
curl -X POST http://localhost:7700/indexes/movies/documents \
  -d '[
    {"objectID":"1","title":"The Matrix","year":1999},
    {"objectID":"2","title":"Inception","year":2010}
  ]'

# Search
curl "http://localhost:7700/indexes/movies/search?q=matrxi"

flapjack uninstall

Quickstart API

Method	Endpoint	Description
GET	/indexes	List all indexes
GET	/indexes/:name/search?q=...	Search (query params)
POST	/indexes/:name/search	Search (JSON body)
POST	/indexes/:name/documents	Add/update documents
GET	/indexes/:name/documents/:id	Get a document
DELETE	/indexes/:name/documents/:id	Delete a document
POST	/indexes/:name/documents/delete	Bulk delete by ID array
GET	/indexes/:name/settings	Get index settings
PUT	/indexes/:name/settings	Update index settings
DELETE	/indexes/:name	Delete an index
GET	/tasks/:taskId	Check task status
POST	/migrate	Migrate from Algolia

These are convenience endpoints with no auth required in dev mode. The full Algolia-compatible API lives under /1/ with support for API keys, secured keys, filters, facets, and everything else.

Note:

Binaries: Releases.

# Install specific version
curl -fsSL https://install.flapjack.foo | sh -s -- v0.2.0

# Custom install directory
FLAPJACK_INSTALL=/opt/flapjack curl -fsSL https://install.flapjack.foo | sh

# Skip PATH modification
NO_MODIFY_PATH=1 curl -fsSL https://install.flapjack.foo | sh

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Migrate from Algolia

flapjack

curl -X POST http://localhost:7700/migrate \
  -d '{"appId":"YOUR_ALGOLIA_APP_ID","apiKey":"YOUR_ALGOLIA_ADMIN_KEY","sourceIndex":"products"}'

Search:

curl "http://localhost:7700/indexes/products/search?q=widget"

Then point your frontend at Flapjack instead of Algolia:

import algoliasearch from 'algoliasearch';

// app-id can be any string, api-key is your FLAPJACK_ADMIN_KEY or a search key
const client = algoliasearch('my-app', 'your-flapjack-api-key');
client.transporter.hosts = [{ url: 'localhost:7700', protocol: 'http' }];

// Everything else stays the same

InstantSearch.js widgets work as-is — SearchBox, Hits, RefinementList, Pagination, GeoSearch, etc.

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Features

Feature	Details
Full-text search	Prefix matching, typo tolerance (Levenshtein ≤1/≤2)
Filters	Numeric, string, boolean, date — AND/OR/NOT
Faceting	Hierarchical, searchable, filterOnly, wildcard *
Geo search	aroundLatLng, insideBoundingBox, insidePolygon, auto-radius
Highlighting	Typo-aware, supports nested objects and arrays
Custom ranking	Multi-field, asc/desc
Synonyms	One-way, multi-way, alternative corrections
Query rules	Rewrite queries, pin/hide results
Pagination	page/hitsPerPage and offset/length
Distinct	Deduplication by attribute
Stop words & plurals	English built-in
Batch operations	Add, update, delete, clear, browse
API keys	ACL, index patterns, TTL, secured keys (HMAC)
S3 backup/restore	Scheduled snapshots, auto-restore on startup

Algolia-compatible REST API under /1/ — works with InstantSearch.js v5, the algoliasearch client, and Laravel Scout.

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Comparison

	Flapjack	Algolia	Meilisearch	Typesense	Elasticsearch	OpenSearch
Self-hosted	✅	❌	✅	✅	✅	✅
License	MIT	Proprietary	MIT	GPL-3	ELv2 / SSPL / AGPL	Apache 2.0
Algolia-compatible API	✅	—	❌	❌	❌	❌
InstantSearch.js	Native	Native	Adapter	Adapter	Community	Community
One-click Algolia migration	✅	—	❌	❌	❌	❌
Typo tolerance	✅	✅	✅	✅	✅	✅
Faceting (hierarchical)	✅	✅	✅	✅	✅	✅
Filters (numeric, string, bool, date)	✅	✅	✅	✅	✅	✅
Geo search	✅	✅	✅	✅	✅	✅
Synonyms	✅	✅	✅	✅	✅	✅
Query rules (pin/hide)	Basic	✅	❌	✅	✅	✅
Custom ranking	✅	✅	✅	✅	✅	✅
Analytics	Basic	✅	Cloud only	✅	✅	✅
Scoped API keys (HMAC)	✅	✅	✅	✅	✅	❌
S3 backup/restore	✅	N/A	❌	❌	Snapshots	Snapshots
Dashboard UI	✅	✅	✅	Cloud only	Kibana	Dashboards
Embeddable as library	✅	❌	❌	❌	❌	❌
HA / clustering	❌	✅	Cloud only	✅	✅	✅
Multi-language	English only	60+	Many	Many	Many	Many
Vector / semantic search	❌	✅	✅	✅	✅	✅
AI search (RAG)	❌	✅	✅	✅	✅	✅
Hybrid search (keyword + vector)	❌	✅	✅	✅	✅	✅
A/B testing	❌	✅	❌	❌	❌	Partial

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Deployment

cargo build --release
./target/release/flapjack

Requires Rust 1.70+. Pre-built binaries for Linux x86_64 (static musl), Linux ARM64, macOS Intel, and macOS Apple Silicon on the releases page.

Docker

# docker-compose.yml
services:
  flapjack:
    image: flapjack/flapjack:latest
    ports:
      - "7700:7700"
    volumes:
      - ./data:/data
    environment:
      FLAPJACK_DATA_DIR: /data
      FLAPJACK_ADMIN_KEY: ${ADMIN_KEY}
    restart: unless-stopped

Systemd

# /etc/systemd/system/flapjack.service
[Unit]
Description=Flapjack Search Server
After=network.target

[Service]
Type=simple
User=flapjack
WorkingDirectory=/var/lib/flapjack
Environment=FLAPJACK_DATA_DIR=/var/lib/flapjack/data
Environment=FLAPJACK_ADMIN_KEY=your-key
ExecStart=/usr/local/bin/flapjack
Restart=always

[Install]
WantedBy=multi-user.target

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Configuration

Variable	Default	Description
FLAPJACK_DATA_DIR	./data	Index storage directory
FLAPJACK_BIND_ADDR	127.0.0.1:7700	Listen address
FLAPJACK_ADMIN_KEY	—	Admin API key (enables auth)
FLAPJACK_ENV	development	production requires auth on all endpoints
FLAPJACK_S3_BUCKET	—	S3 bucket for snapshots
FLAPJACK_S3_REGION	us-west-1	S3 region
FLAPJACK_SNAPSHOT_INTERVAL	—	Auto-snapshot interval (e.g. 6h)
FLAPJACK_SNAPSHOT_RETENTION	—	Retention period (e.g. 30d)

Data stored in FLAPJACK_DATA_DIR. Mount as a volume in Docker.

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API Documentation

• Online API docs
• Swagger UI (local)

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Use as a Library

Flapjack's core can be embedded directly:

[dependencies]
flapjack = { version = "0.1", default-features = false }

See LIB.md for the embedding guide.

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Architecture

Built on Tantivy (forked for edge-ngram prefix search). Axum + Tokio HTTP server. Supports 600+ indexes per 4GB node.

flapjack/              # Core library (search, indexing, query execution)
flapjack-http/         # HTTP server (Axum handlers, routing)
flapjack-replication/  # Cluster coordination
flapjack-ssl/          # TLS (Let's Encrypt, ACME)
flapjack/       # Binary entrypoint

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Development

cargo install cargo-nextest
cargo nextest run

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Roadmap

Security

• Hash API keys at rest (salted SHA-256)
• Admin key on first boot only
• Key type prefixes (fj_admin_, fj_search_)

Infrastructure

• High availability — multi-node replication
• Managed cloud (SaaS)

Search

• Vector / hybrid search
• AI search (RAG)
• A/B testing
• Multi-language support

Platform

• Webhooks
• Role-based access control

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Dashboard Screenshots

Flapjack includes a built-in dashboard UI served at http://localhost:7700 when the server is running.

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License

MIT