# Chessigma API

> Source: <https://www.chessigma.com/developers>
> Published: 2026-11-06 05:28:55+00:00

For AI agents: the documentation index is at https://www.chessigma.com/llms.txt, and this page is available as Markdown at https://www.chessigma.com/developers.md.

v1.0.0
A free API for chess game analysis. Submit a game, read its analysis, calculate rating changes, and fetch the daily puzzle. No API key, no signup, no paywall.

Base URL`https://www.chessigma.com/public-api/v1`

No API key or account. Every endpoint is open.

A shared global limit. Over it returns 429.

Engine analysis runs in the browser. Submit a game, then open its URL to analyze.

Please attribute Chessigma when you use the API. By using it you accept the [terms of service](https://www.chessigma.com/tos).

Submit a game, then open the returned URL to view and analyze it.

```
curl -X POST https://www.chessigma.com/public-api/v1/game \
  -H "Content-Type: application/json" \
  -d '{"pgn": "[White \"Alice\"]\n[Black \"Bob\"]\n[Result \"1-0\"]\n\n1. e4 e5 2. Nf3 Nc6 1-0"}'

# 201 Created
# { "gameId": "f222a278-...", "url": "https://www.chessigma.com/games/f222a278-...", "status": "submitted" }
```

`/game`
Submit a game (PGN) for analysis

Stores a chess game and returns a URL to view and analyze it on Chessigma. Duplicate games (same players + date) are deduplicated and return the existing gameId.

`/game/{gameId}`
Retrieve analysis for a submitted game

Returns game metadata and analysis. Because analysis runs client-side, this returns data only if a user has already opened the game page and triggered analysis. Only games submitted via this public API are readable here.

`/elo-calculator`
Compute an Elo rating change for a single game

Pure arithmetic. Returns the new rating, point change, and expected score.

`/daily-puzzle`
Get the daily chess puzzle

Returns the single daily puzzle for today, or a past date via ?date=YYYY-MM-DD. Returns exactly one puzzle. The full puzzle database is not exposed.

Full request and response schemas are in the [OpenAPI spec](https://www.chessigma.com/openapi.json).

You do not always need the API. These URLs drop a user straight into a live, client-side tool. Standardize on `fen` for positions and `pgn` for games. URL-encode the value.

`/tools/analysis?fen=<FEN>`
Opens the live analysis board on a position.

`/tools/analysis?pgn=<PGN>`
Loads a game for move-by-move replay and analysis.

`/tools/next-move?fen=<FEN>`
Finds the engine's best move for a position.

`/tools/analysis/editor?fen=<FEN>`
Opens the board editor on a position.

`/games/<gameId>?move=<n>`
Jumps to a specific move in a submitted game.

Chessigma publishes a machine-readable discovery surface so AI agents can find and use it.

`/openapi.json`: the OpenAPI 3.1 contract.`/.well-known/api-catalog`: RFC 9727 catalog.`/.well-known/agent-skills/index.json`: the agent skill index.