One

One, built by One Systems, Inc., is an agent infrastructure platform that gives AI agents authenticated access to over 500 platforms and 102,000+ tools through a single CLI and SDK. The company raised $4M to build what it describes as "the trust layer for AI agents," handling OAuth flows, token refresh, rate limiting, and multi-tenant credential isolation so developers don't have to wire up each API themselves. One is compatible with every major AI agent framework including Claude Code, OpenAI Codex, Cursor, GitHub Copilot, Windsurf, Cline, Gemini, and more.

What It Is

One is an integration runtime that sits between AI agents and the APIs they need to take real-world actions. Rather than requiring developers to read API docs, implement OAuth, handle rate limiting, and write platform-specific code for each integration, One provides a single interface — the One CLI — that exposes all 500+ platforms through four commands: list, search, knowledge, and execute. The platform also includes managed auth (One Auth), a multi-step workflow engine (One Flow), an agent deployment layer (One Agents), and a "Bridge" product that turns any API into an MCP server by pasting a docs URL.

Core Products and Architecture

One ships six primitives under one platform:

• One CLI — A single command-line interface to find, inspect, and execute actions across 500+ platforms. Auth is handled automatically; rate limits and errors are managed transparently.
• One Auth (AuthKit) — Managed OAuth 2.0, OAuth 1.0a, API key, and Basic Auth lifecycle management with automatic token refresh, multi-tenant credential isolation, SSO, SCIM, and granular access policies.
• One Agents — Deploy AI agents to Slack, WhatsApp, and Telegram with built-in skills, event-driven webhooks, scheduled cron tasks, and fleet management.
• One Flow — Chain multi-step actions across apps, pass data between steps, handle errors, and pause/resume workflows.
• One Bridge — Paste an API docs URL; Bridge discovers endpoints, maps auth, optimizes context windows, and generates a production-ready MCP server.
• One Knowledge — An open-source API knowledge base with structured, human-verified schemas for every tool across 500+ platforms, including parameters, auth flows, response schemas, and examples.

Context Efficiency and Token Architecture

One addresses a core problem in agentic AI: loading tool schemas into the LLM context window. The homepage illustrates that connecting to eight major platforms (HubSpot, GitHub, Zendesk, Jira, Stripe, Linear, Slack, Gmail) would require approximately 810,900 tokens of tool schemas in the prompt before a task even starts. With One, the agent sees only four commands (~3,000 tokens), and full action schemas are loaded on demand via one actions knowledge. This lazy-loading architecture keeps context windows lean regardless of how many platforms are connected.

Open Source Knowledge Base

The One Knowledge repository on GitHub (withoneai/knowledge) is described by the company as "the world's largest API knowledge base, built for agents." It contains structured knowledge for 102,000+ tools across 691 platforms, including metadata, authentication flows, action definitions, parameters, enforcement rules, response schemas, and real request/response examples. The repository is available under the One Knowledge Commons License v1.0 (OKCL-1.0), which permits free use with attribution but restricts use in competing integration knowledge bases and requires commercial licensing for integration infrastructure companies above $1M annual revenue. The SDK, CLI, and MCP tools are separately available on GitHub under the withoneai organization.

Agent Compatibility and Deployment

One's homepage states it works with every major AI agent, listing Claude Code, OpenClaw, Codex, Cursor, GitHub Copilot, Windsurf, AMP, Antigravity, Cline, Droid, Gemini, Goose, Kilo, Kiro CLI, OpenCode, Roo, Trae, Warp Agent CLI, and Muse Code. The platform is framework-agnostic and works with OpenAI, Anthropic, LangChain, CrewAI, Vercel AI SDK, or custom code. The company publishes open-source use-case repos covering operations (on-call review with Datadog + Linear), sales ops (renewal risk radar with HubSpot + Gmail), go-to-market (lead research with Exa + Claude), finance (AR collections with QuickBooks + Gmail), and more.

Update: $4M Seed and Open-Source Knowledge Launch

One Systems, Inc. announced a $4M raise to build the trust layer for AI agents, disclosed on the homepage banner. Concurrently, the company open-sourced its full API knowledge base at withone.ai/knowledge, describing it as "the world's largest app knowledge base." The GitHub repository was created in March 2026 and last updated in August 2026, with 251 stars and 35 forks as of the latest data. The platform reports 99.9% uptime and sub-100ms p95 latency, and the company states it is SOC 2 compliant.