Build on verified commerce
Crinkl verifies real-world spend and produces identity-free spend tokens — cryptographic proofs with no personal data. Query verified commerce data via MCP, submit billing emails via REST, or build your own agent.
crinkl-agent
Open-source reference agent. Scans email for DKIM-signed billing receipts and earns sats over Lightning. Supports Gmail (OAuth) or AgentMail (dedicated inbox, no OAuth). Run standalone with npx crinkl-agent or install as an OpenClaw skill.
15 public tools + 6 agent tools via Streamable HTTP
Read-only commerce intelligence is public. The same MCP server also exposes agent tools for vendor discovery, human-authorized pairing, receipt submission, and earnings.
{
"mcpServers": {
"crinkl": {
"url": "https://mcp.crinkl.xyz/mcp"
}
}
}Public read-only tools
Concise explanation of what Crinkl is and how the protocol works.
All-time cumulative Gross Merchandise Value verified by the protocol.
Signed GMV summary for a specific calendar date (UTC).
Rolling N-day GMV trend summary.
Recent verified spend activity signals from the network.
Resolve a CBSA code to its metro area name.
Aggregated merchant and category distribution across verified spends.
Geographic and category distribution over a trailing window.
Bitcoin settlement statistics for the network.
Merkle inclusion proof that a spend is included in a daily GMV total.
Verify a reward commitment token's cryptographic integrity.
Full end-to-end verification of a spend's inclusion in verified GMV.
Recently issued proof bundles demonstrating end-to-end verifiability.
Ed25519 public key used to sign all attestation tokens.
Current reward policy (sats/receipt rate, category multipliers, reserve).
Agent tools
6 additional MCP tools handle vendor discovery, pairing, receipt submission, and scoped earnings. Pairing always requires a human to approve the 4-character code in the Crinkl PWA.
List currently approved DKIM vendor domains used to seed Gmail searches.
Start pairing by generating a 4-character code. A human must approve it in the Crinkl app before the agent can claim its key.
Poll for the API key after the human approves the pairing code in the app.
Preview DKIM verification of a billing email without creating a spend.
Submit a DKIM-verified billing email to mint a spend token and earn sats.
Return submission count, earned sats, and wallet-level stats for an API key.
Base URL: https://api.crinkl.xyz
Agent endpoints
Submit billing emails and earn sats. Get an API key from app.crinkl.xyz (Profile → Agent Keys) or via the pairing flow. The pair endpoint only creates the short-lived code; a human approves that code inside the PWA. Pass agentmailInbox in the pair request to bind an AgentMail inbox.
List currently approved DKIM vendor domains used to seed Gmail search queries. Unknown domains queue for review on submission.
Start pairing by generating a 4-character code. A human must approve it in the Crinkl app before the agent can claim its key. Optional: pass agentmailInbox to bind an AgentMail inbox.
Fetch pairing metadata (AgentMail inbox, expiry) for the logged-in PWA user before approval.
Poll for API key after the human approves the pairing code in the app.
Submit base64 .eml for DKIM verification + spend creation.
Preview verification without creating a spend.
Your submission count, earned sats, wallet stats.
Retrieve the signed spend attestation token.
Public endpoints
Signed JSON responses. No authentication required.
Signed cumulative GMV token.
Daily GMV summary.
Trailing N-day GMV trend.
Recent spend signals.
Merchant distribution.
CBSA code resolver.
Bitcoin settlement stats.
GMV Merkle inclusion proof.
Verify reward commitment.
Recent composed proofs.
Full end-to-end GMV verification.
Ed25519 public key.
Reward policy.
Active predicates.
12 canonical categories.
CBSA code list.