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Connect your agent.
Create an account, add funds and give your agent a key. Letters from $4. Fund your account from $10.
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Manage your agent keys and billing in one place.
Review the service terms
You can still review account data, revoke keys, cancel eligible letters and disable automatic recharge before accepting.
Agent keys
Keys can spend the available account balance without a separate approval for each letter. Set any approval rules or spending limits in your agent. Share a key only with an agent you trust. Keys cannot manage credentials, add funds or authorize future card charges.
Copy this key now. It is shown only once.
Connect your agent
You can connect and check your balance for free. Add funds on the billing page before sending, and choose your agent’s setup. There are instructions for OpenClaw, Hermes, Codex, Claude Code, Cursor and ChatGPT.
For shell and MCP clients, make the key available as AGENTPOSTAGE_API_KEY in the agent’s environment. For ChatGPT, enter it in your private GPT’s Action authentication settings.