Chess Infrastructure, Unified

The operating system
behind Posira

One API where five disconnected ones exist today. Game data, engine analysis, move validation, opening databases — all in one developer-first platform.

analyze.ts 
const analysis = await posira.analyze({
  fen: "rnbqkbnr/pppp...",
  depth: 20,
  lines: 3
});

// Engine eval + opening book
// + position stats in one call
console.log(analysis.bestMove);
console.log(analysis.opening);
console.log(analysis.winRate);

The chess developer stack is fragmented

Before Posira
  • Chess.com API for player data
  • Lichess API for game streams
  • Self-hosted Stockfish for analysis
  • Custom code for move validation
  • Another library for opening books
5 services. 5 rate limits. 5 failure modes.
With Posira
posira.analyze()
posira.validate()
posira.openings()
posira.games()
One API. One key. One bill.

Built for builders

♘

Engine Analysis

Cloud-hosted Stockfish with configurable depth, multi-line analysis, and position evaluation. No server management required.

♖

Move Validation

Legal move generation, check detection, and game state tracking via a clean REST endpoint. Ship a chess app in hours, not weeks.

♕

Opening Database

Millions of master games indexed by position. Get opening names, move statistics, and win rates from a single query.

♔

API Explorer

Interactive endpoint testing at posira.dev/explorer. See requests, responses, and code samples before writing a single line.

♞

Every chess app deserves
production-grade infrastructure

Posira exists because building chess applications shouldn't require stitching together five different APIs, managing your own Stockfish server, and writing move validation from scratch. Developers deserve a single, reliable, well-documented chess backend that just works.

Chess infrastructure. Solved once. Used everywhere.