Lichess is a free, ad-free, open-source online chess server operated by a French nonprofit and powered entirely by volunteers and donations. It serves millions of games per day with live play, tournaments, puzzles, studies, broadcasts, analysis, and a public API. The server (lila), engine library (scalachess), mobile app, board UI (chessground), and distributed Stockfish analysis network (fishnet) are all open source under AGPL-3.0, MIT, and GPL-3.0 licenses. The Lichess API provides 185 documented operations across 23 functional areas with comprehensive ND-JSON streaming support.
URL: Visit APIs.json
Run: Capabilities Using Naftiko
- Chess, Games, Open Source, Nonprofit, Tournaments, Puzzles, Bots, Streaming, ND-JSON, OAuth
- Created: 2026-05-25
- Modified: 2026-05-25
| Item | Value |
|---|---|
| OpenAPI version | 3.1.0 |
| Spec version | 2.0.144 |
| Operations | 185 |
| Tag groups | 23 |
| Base URL | https://lichess.org |
| Streaming format | ND-JSON (newline-delimited JSON) |
| Auth | OAuth 2.0 PKCE, Personal Access Tokens (bearer) |
| Server license | AGPL-3.0-or-later (lila) |
| Engine library | MIT (scalachess) |
| Mobile app | GPL-3.0 (mobile) |
| Governance | Lichess (French nonprofit), volunteer-driven |
| Funding | Patron donations (lichess.org/patron) |
Comprehensive REST and streaming API covering account, users, games, puzzles, teams, challenges, board and bot play, Arena and Swiss tournaments, simuls, studies, broadcasts, messaging, OAuth, FIDE, opening explorer, tablebase, external engine, and cloud evaluation.
Human URL: https://lichess.org/api
- API Reference
- OpenAPI 3.1 (bundled, local)
- OpenAPI source repo
- JSON Schema — Game
- JSON Schema — User
- JSON-LD context
One self-contained capability per Lichess API tag.
| Tag | Operations | Capability |
|---|---|---|
| Account | 6 | account |
| Analysis (Cloud eval) | 1 | analysis |
| Board | 13 | board |
| Bot | 12 | bot |
| Broadcasts | 19 | broadcasts |
| Bulk pairings | 6 | bulk-pairings |
| Challenges | 11 | challenges |
| External engine | 8 | external-engine |
| FIDE | 3 | fide |
| Games | 13 | games |
| Messaging | 1 | messaging |
| OAuth | 4 | oauth |
| Opening Explorer | 4 | opening-explorer |
| Puzzles | 11 | puzzles |
| Relations | 5 | relations |
| Simuls | 1 | simuls |
| Studies | 9 | studies |
| Tablebase | 3 | tablebase |
| Teams | 14 | teams |
| Tournaments (Arena) | 13 | arena-tournaments |
| Tournaments (Swiss) | 10 | swiss-tournaments |
| TV | 4 | tv |
| Users | 13 | users |
Lichess is open source from the ground up. The repos below are the canonical ones for the platform.
lila— main Lichess server, Scala, AGPL-3.0api— OpenAPI specs, docs, and examples for the public APIscalachess— chess engine library, MITchessground— web/mobile chess board UI, GPL-3.0pgn-viewer— embeddable PGN viewer widgetmobile— official Flutter mobile app, GPL-3.0fishnet— distributed Stockfish analysis network, GPL-3.0lila-ws— websocket serverlila-openingexplorer— opening explorer backendlila-tablebase— 7-piece Syzygy tablebase serverlila-engine— external engine brokerlila-gif— GIF rendering microservicebroadcaster— live event broadcast toolexternal-engine— Python client for hosting your own analysis enginedatabase— public dataset exports (games, puzzles, evals)
| Language | Library | Source |
|---|---|---|
| Python | berserk | lichess-org/berserk |
| Python (async) | async-lichess-sdk | pypi.org/project/async-lichess-sdk |
| MicroPython | uberserk | mkomon/uberserk |
| Python (bot framework) | lichess-bot | lichess-bot-devs/lichess-bot |
| Java | chariot | tors42/chariot |
| JavaScript / TypeScript | equine | devjiwonchoi/equine |
| .NET | LichessSharp | Dblike/LichessSharp |
| C# | LichessNET | Rabergsel/LichessNET |
See the Capability Coverage table above. All 23 capabilities live under capabilities/ and each is a self-contained Naftiko consumes/exposes definition with REST and MCP adapters.
- Plans / Pricing — Lichess is free; an optional Lichess Patron donation tier is documented but provides no functional gating
- Rate Limits — per-endpoint guidance plus the global "one request at a time, back off 60s on 429" policy
Lichess publishes complete public dataset exports under the Creative Commons CC0 license.
- database.lichess.org — all rated games in PGN, all puzzles with themes and ratings, all evaluated positions
- Personal API access tokens: lichess.org/account/oauth/token
- OAuth 2.0 Authorization Code Flow with PKCE; long-lived access tokens (typical one-year lifetime); no refresh tokens
- See the OAuth examples in lichess-org/api/example
FN: Kin Lane
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X: apievangelist