For tool builders
How it works
- Your tool gets its own page in the Attest toolbox, in the OpenAPI description and in the Attest MCP server, so agents discover it where they already look.
- Agents call it with their Attest key. Attest checks the input against the schema you publish, then calls your HTTPS endpoint. Each call carries
attest-call-id, attest-timestamp and attest-signature, an HMAC-SHA256 signature made with a secret only you and Attest know, so you can refuse anything that did not come from Attest. The exact check is in the seller terms.
- Your endpoint answers with JSON. Attest returns it to the agent with the seller named, charges the credits you set, and refunds the call automatically if your endpoint fails.
- Attest never sends your endpoint the caller's key, email or payment details, only the input for your tool.
Before you apply
Requirements
- A public HTTPS endpoint that accepts a JSON POST and answers with a JSON object within 10 seconds and under 256 KB.
- An input schema: named fields with types and limits, nothing open-ended.
- A clear description of what the tool does and when an agent should use it.
- No collection of personal information beyond what the tool needs, and compliance with the Acceptable Use Policy.
Checked before listing
Review
Every tool is tested before it goes live: the endpoint must answer correctly to valid input, refuse bad input cleanly, stay inside the time and size limits, and match its description. Tools that stop passing are unlisted.
Revenue
Payouts
Seller payouts open after Attest's launch review. Applications are being accepted now; revenue share terms are agreed with each seller in writing before their tool goes live.
Apply
Apply to sell
Use the support form, choose "Sell on Attest", and include your endpoint URL, what the tool does, and its input fields.
