System One｜面向 AI Agent 的决策 API 与 TypeScript SDK

# System One > Build AI agent decisions with an open-source TypeScript SDK and a hosted decision API. Turn text and application state into choices, scores, and probabilities for tool routing, ranking, and condition checks. Use the SDK to define questions and handle typed results. Connect it to System One API for hosted inference, or configure a supported provider directly. Your code controls what happens next. ## When to use System One Use System One to route a request among named choices, score a condition against an ordered rubric, or estimate P(true) before an application branches. Define the answer space first. Keep business actions in application code, and escalate uncertain decisions to a person or a reasoning model. Validate performance on representative inputs before relying on a threshold. ## Start here - [Developer documentation](https://docs.system-one.dev/en) - [Versioning and deprecation](https://docs.system-one.dev/en/docs/api/versioning) - [Idempotency and retries](https://docs.system-one.dev/en/docs/api/idempotency) - [API errors](https://docs.system-one.dev/en/docs/api/errors) - [TypeScript SDK](https://system-one.dev/en/sdk) - [API reference](https://system-one.dev/en/api) - [Models](https://system-one.dev/en/models) - [Model catalog](https://docs.system-one.dev/en/docs/models) - [Authentication](https://system-one.dev/en/auth.md) - [Pricing](https://system-one.dev/en/pricing) - [Credit billing](https://docs.system-one.dev/en/docs/billing) - [OpenAPI specification](https://system-one.dev/openapi.json) - [Agent integration guide](https://system-one.dev/en/skill.md) - [System One for Coding Agents: Cursor, Claude Code, Codex](https://docs.system-one.dev/en/docs/coding-agents) - [Installable coding-agent skill](https://system-one.dev/skills/system-one/SKILL.md) - [About](https://system-one.dev/en/about) - [Contact](https://system-one.dev/en/contact) - [Playground samples](https://system-one.dev/en/demo) - [Blog](https://system-one.dev/en/blog) -

{ "openapi": "3.1.1", "jsonSchemaDialect": "https://json-schema.org/draft/2020-12/schema", "info": { "title": "System One API", "version": "typesafe-2026-09-18", "description": "Unified interface for System One models. GET /v1/models is public. POST /v1/systemone requires a platform Bearer key and accepts decision questions or extraction fields. Native TypeSafe, Cloudflare Workers AI and OpenRouter modes have the explicitly documented differences below. Platform billing and tra