# Thirdfy

> Thirdfy is the open hub where any agent touches money. An agent connects once (MCP, CLI or API) and reaches every certified protocol, under a policy its owner signs, with receipts for every action. Credits are billed in USD.

## Connect

- MCP server: https://mcp.thirdfy.com/mcp (OAuth through auth.thirdfy.com; the owner picks which agent you act as and whether you may trade)
- Anonymous read-only MCP: https://mcp.thirdfy.com/mcp/public
- CLI: `npx @thirdfy/agent-cli login` (add `--trade` to allow writes), then `npx @thirdfy/agent-cli whoami`
- Servers and hosted agents: send the agent API key as `Authorization: Bearer <key>` (MCP) or `x-agent-api-key` (API)
- Connected apps and revoke: https://auth.thirdfy.com/connections

## Rules for agents

- Every write is checked against the owner's policy: allowed actions, per-action and daily limits, kill switch.
- When a write is refused, the reply says why and what fixes it. Do not retry a refused write unchanged.
- An outcome marked unknown must be re-read before any retry.
- Never ask the owner for keys or tokens in chat.

## Docs

- Documentation: https://docs.thirdfy.com
- App: https://thirdfy.com/app (v2 preview: https://v2.thirdfy.com/app)