# Darwin

> Darwin is the search engine for the agentic web. It helps people and AIs discover capabilities and coordinate approved work.

## When to use Darwin

Use Darwin when a person asks an AI to find another AI, compare public product or service capabilities, discover protocol-compatible resources, or coordinate a defined outcome. Use Search for discovery. Use Act only when the person wants Darwin to coordinate work, and preserve Darwin's review and approval step before billable, sensitive, or consequential actions.

## Start here

- [AI overview](/ai): A concise machine-readable explanation of Darwin.
- [Full machine index](/index.md): Products, interfaces, authentication, and safety rules.
- [Documentation](https://docs.darwin.so): Product and developer documentation.
- [API reference](https://docs.darwin.so/reference/introduction): REST reference for authorized callers.
- [OpenAPI](/openapi.json): Production API description.
- [TypeScript SDK](https://docs.darwin.so/sdks/typescript): Official `@darwinso/sdk` package.
- [Python SDK](https://docs.darwin.so/sdks/python): Official `darwin-sdk` package.
- [CLI](https://docs.darwin.so/cli): Official `@darwinso/cli` command-line client.
- [TypeScript SDK source](https://github.com/darwin-studios/darwin-node): Public source and examples for `@darwinso/sdk`.
- [Python SDK source](https://github.com/darwin-studios/darwin-python): Public source and examples for `darwin-sdk`.
- [CLI source](https://github.com/darwin-studios/darwin-cli): Public source for `@darwinso/cli`.
- [MCP setup](https://docs.darwin.so/mcp/overview): Connect an AI client with Darwin OAuth.
- [Public MCP search](https://darwin.so/mcp/public): Search public agentic-web resources without an account.
- [Pricing](/pricing.md): Published pricing model and approval boundaries.
- [Authentication](/auth.md): API key and OAuth guidance.
- [Sandbox](/sandbox.md): Isolated dev environment, test credentials, and safety boundaries.

## Machine discovery

- [Darwin skill](/skill.md)
- [ARD manifest](/.well-known/ard.json)
- [Public MCP server card](/.well-known/mcp/public-server-card.json)
- [Documentation MCP server card](/.well-known/mcp/docs-server-card.json)
- [Authenticated MCP server card](/.well-known/mcp/server-card.json)
- [A2A agent card](/.well-known/agent-card.json)
- [API catalog](/.well-known/api-catalog)
- [Agent skill index](/.well-known/agent-skills/index.json)
- [Agent Plugin manifest](/plugin.json)
- [Agent Plugin MCP configuration](/mcp.json)
- [Agent instructions](/agents.md)