@waxseal/mcp

WaxSeal MCP Server — give your AI agents a cryptographic identity layer. Verify who someone is, sign documents, and require explicit human approval before any high-risk action runs.

AI agents can now say: "I have a signed human approval before I do this." And you can verify it's real.

What it enables

• Verify any identity — look up a WaxSeal fingerprint on Ethereum, Base, or BNB Chain and confirm who it belongs to, whether it's active, and what wallet owns it

• Sign documents — attach a tamper-evident Ed25519 signature to any text, code, or artifact — verifiable by anyone, forever

• Human-in-the-loop approvals — create a time-limited approval token that proves you authorized a specific AI action; the agent verifies it before executing

• Verify signatures — confirm that a document or message was signed by the holder of a specific on-chain fingerprint

• No central trust — verification goes directly to the on-chain NFT contract; there is no WaxSeal server in the trust chain

Related MCP server: Agent Receipts

6 tools at a glance

Verify-only tools work with zero configuration. Signing tools require WAXSEAL_PRIVATE_KEY_PEM.

Hosted server — no install needed

Use directly in any HTTP-capable MCP client:

https://api.waxseal.id/mcp

The hosted server provides all 6 tools. Signing tools will return a setup error (private keys cannot run server-side by design — they must stay on your device).

Quick start

Claude Desktop

~/Library/Application Support/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "waxseal": {
      "command": "npx",
      "args": ["-y", "@waxseal/mcp"],
      "env": {
        "WAXSEAL_PRIVATE_KEY_PEM": "-----BEGIN PRIVATE KEY-----\n<your key>\n-----END PRIVATE KEY-----"
      }
    }
  }
}

Cursor

.cursor/mcp.json (project) or ~/.cursor/mcp.json (global)

{
  "mcpServers": {
    "waxseal": {
      "command": "npx",
      "args": ["-y", "@waxseal/mcp"],
      "env": {
        "WAXSEAL_PRIVATE_KEY_PEM": "-----BEGIN PRIVATE KEY-----\n<your key>\n-----END PRIVATE KEY-----"
      }
    }
  }
}

Windsurf

~/.codeium/windsurf/mcp_config.json

{
  "mcpServers": {
    "waxseal": {
      "command": "npx",
      "args": ["-y", "@waxseal/mcp"]
    }
  }
}

Don't have a WaxSeal yet? Get one free at waxseal.id/create — Ed25519 keypair generated in-browser, private key never leaves your device.

Tool reference

waxseal.info

Returns a full overview of the WaxSeal trust infrastructure — 11 trust layers, available tiers, and a guide to the other MCP tools. Call this first if your AI client is unfamiliar with WaxSeal.

No input required.

waxseal.identity.verify

Look up any WaxSeal fingerprint. Returns on-chain status, display name, owner wallet, chain, and lifecycle status.

fingerprint  string  64-char hex (0x prefix optional)

{
  "on_chain": true,
  "display_name": "Ada Lovelace",
  "lifecycle_status": "active",
  "chain": "base",
  "owner_wallet": "0x1234...",
  "minted_at": "2025-01-15T10:00:00Z",
  "verification_url": "https://waxseal.id/seal/a1b2c3..."
}

Example: "Look up WaxSeal a3b4c5d6... and tell me who owns it."

waxseal.document.sign

Signs any text or document with your WaxSeal Ed25519 private key. Returns a fingerprint, SHA-256 content hash, and base64 signature verifiable by anyone with waxseal.signature.verify.

Requires WAXSEAL_PRIVATE_KEY_PEM.

content      string   the document or text to sign
description  string?  optional label (informational only)

{
  "fingerprint": "a1b2c3...",
  "content_hash": "sha256hex...",
  "signature": "base64...",
  "signed_at": "2026-06-01T12:00:00Z"
}

Example: "Sign this contract with my WaxSeal key."

waxseal.signature.verify

Verifies an Ed25519 signature against the public key stored on-chain for the given fingerprint. The seal must be active for verification to pass.

content      string  the original document that was signed
fingerprint  string  64-char hex fingerprint of the claimed signer
signature    string  base64 Ed25519 signature

{
  "valid": true,
  "signer": "Ada Lovelace",
  "chain": "Base",
  "message": "Signature is valid. Signed by Ada Lovelace (a1b2c3...)."
}

Example: "Verify this signature from fingerprint a1b2c3... against the document."

waxseal.approval.create

Creates a cryptographically signed approval token proving you explicitly authorized a specific action. The token is time-limited, tamper-evident, and tied to your on-chain identity.

Requires WAXSEAL_PRIVATE_KEY_PEM.

action              string   description of the action being approved
context             string?  optional additional parameters or context
expires_in_minutes  number?  default 10

{
  "approval_token": "base64...",
  "action": "Deploy v2.1.0 to production",
  "expires_at": "2026-06-01T12:10:00Z",
  "instructions": "Pass approval_token to the agent. Agent calls waxseal.approval.verify before executing."
}

Example: "Create an approval for the agent to deploy v2.1.0 to production, valid for 5 minutes."

waxseal.approval.verify

Verifies an approval token before executing a high-risk or irreversible action. Returns valid: true only when the token is cryptographically authentic, unexpired, and the signer has an active on-chain seal.

approval_token        string   token from waxseal.approval.create
expected_fingerprint  string?  require a specific signer (optional)

{
  "valid": true,
  "action": "Deploy v2.1.0 to production",
  "signer": "Ada Lovelace",
  "seconds_remaining": 287,
  "message": "Approval is valid. Authorized by Ada Lovelace. Expires in 287s."
}

Example: "Before you deploy, verify this approval token: [token]"

Human-in-the-loop pattern

The standard problem with autonomous AI agents is that they execute consequential actions — deploys, transfers, deletions — without cryptographic proof that a human actually approved it at that moment.

WaxSeal solves this:

1.  Human → Claude: "Deploy when ready. Here's my approval:"
2.  Human runs:   waxseal.approval.create({ action: "Deploy v2.1.0", expires_in_minutes: 30 })
3.  Claude stores the approval_token
4.  Claude finishes work, then calls: waxseal.approval.verify({ approval_token })
5.  valid: true  →  Claude deploys
    valid: false →  Claude stops and requests a fresh approval

The approval signature is tied to an on-chain WaxSeal identity — unforgeable by the agent, auditable after the fact, and automatically expired.

Environment variables

Security model

• Private keys never leave your machine. The local MCP server reads your key from the environment variable only — it is never transmitted or logged.

• Verification is on-chain. Public keys are read from the WaxSeal NFT contract on Ethereum, Base, or BNB Chain — not from a WaxSeal-controlled database.

• Approval tokens are replay-proof. Each token encodes the action, expiry, and an Ed25519 signature. A tampered or expired token returns valid: false.

• No key, no signing. The hosted server at api.waxseal.id/mcp intentionally cannot sign — private keys must stay on the user's device.

Get your seal

1. Go to waxseal.id/create

2. Generate your Ed25519 keypair in-browser (private key never transmitted)

3. Mint your seal on Base, Ethereum, or BNB Chain

4. Export the private key PEM and set WAXSEAL_PRIVATE_KEY_PEM

Free tier includes identity minting. Developer tier ($49/mo) unlocks AI agent signing, payment routing, and webhook authentication.

Links

MIT License © Wax Seal