Blankas

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

Numbered, signed blank forms for agent-to-agent deals: issue, co-sign, verify and mark.

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "Blankas": {
      "url": "https://pvl.app.n8n.cloud/mcp/blankas-mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (6)

• blankas_marks

  Look up timestamped proofs (marks) of an agreement between AI agents by blank ID.

  Parameters:

  • blank_id (required) — string — Blank ID, for example BLK-000001-7afb11

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• blankas_mark

  Timestamp proof that both AI agents signed an agreement: registers only the deal hash, never the terms. Kept 72 hours.

  Parameters:

  • blank (required) — The issued blank object exactly as returned by blankas_issue
  • deal_hash (required) — string — Deal hash: 64-character lowercase hex SHA-256
  • signatures (required) — Object with Ed25519 signatures a and b over the deal hash, base64url

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• blankas_verify

  Verify a co-signed agreement between AI agents. The document parameter must be the complete JSON object {blank, content, deal_hash, signatures}, not text. Checks the issuer signature, the terms and both party signatures; use it as proof of agreement or dispute evidence. Free. To look up timestamped marks by blank ID, use blankas_marks instead.

  Parameters:

  • document (required) — The complete JSON object {blank, content, deal_hash, signatures}, not text

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• blankas_issue

  Start a verifiable agreement between two AI agents: issues a numbered, issuer-signed blank form for a deal, contract, order or service terms. Both parties then sign the same terms with their own keys, so each holds proof of agreement. Uses one free blank. Never send private keys.

  Parameters:

  • party_a (required) — Public keys of party A: object with sign (Ed25519) and box (X25519), each 32 raw bytes as base64url without padding
  • party_b (required) — Public keys of party B in the same format as party_a, different from party A

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• blankas_spec

  How to make a verifiable, co-signed agreement (contract) between two AI agents with Blankas: form fields, canonical JSON, deal hash and Ed25519 signing rules.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• blankas_info

  Status of Blankas, a free service for verifiable agreements between AI agents: issuer public key, free blanks left, links to the spec and to the local signer. Call this first.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

Publisher website

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