TAP Protocol

Trusted Agent Protocol (TAP) — cryptographic identity verification for AI agents with Ed25519/ECDSA signatures, attestations, and trust scoring.

Supported Algorithms

Algorithm	Use Case
`Ed25519`	Fast signatures, agent identity
`ECDSA-P256`	Web compatibility, hardware security
`secp256k1`	Ethereum compatibility

Agent Identity

Each agent has a cryptographic identity registered with Sardis:

{
  "agent_id": "agent_abc123",
  "public_key": "0x04...",
  "algorithm": "Ed25519",
  "attestations": [
    {
      "issuer": "sardis.sh",
      "type": "verified_agent",
      "issued_at": "2026-01-01T00:00:00Z"
    }
  ]
}

Verification

from sardis import SardisClient

async with SardisClient(api_key="sk_...") as client:
    # Verify agent identity
    result = await client.tap.verify_identity(
        agent_id="agent_abc123",
        signature="0x...",
        message="payment_request_123",
    )

    if result.verified:
        print(f"Agent verified: {result.attestations}")
    else:
        print(f"Verification failed: {result.reason}")

Attestation Types

verified_agent — Basic identity verification
kyc_verified — KYC/AML compliance
merchant — Verified merchant status
trusted_platform — Platform-level trust

TAP attestations are checked automatically by the Sardis policy engine during AP2 mandate chain verification and A2A inter-agent communication.

TAP Protocol

Supported Algorithms

Agent Identity

Verification

Attestation Types

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