What is ATP?
The Agent Trust Protocol (ATP) is a minimal protocol for signed agent interactions. It provides:
- Identity — Cryptographic proof of who an agent is
- Attestations — Sats-weighted vouches from one agent for another
- Receipts — Mutually-signed proof of completed exchanges
Why ATP?
AI agents need identity. They need to prove who they are, build reputation, and establish trust with other agents. Existing solutions are either:
- Centralized — Single points of failure, gatekeepers, permissioned
- Complex — Over-engineered, hard to implement, slow to verify
- Ephemeral — Identities that can disappear or be revoked arbitrarily
ATP is different:
| Property | ATP |
|---|---|
| Storage | Bitcoin inscriptions |
| Authority | None — permissionless |
| Verification | Cryptographic signatures |
| Permanence | Immutable once inscribed |
| Cost | ~$1-20 per identity |
Core Principles
1. Bitcoin-Native
Everything is stored on Bitcoin. No IPFS, no external databases, no dependencies. The blockchain is both the source of truth AND the data layer.
2. Signature is Identity
Your cryptographic key is your identity. Not your wallet, not your username, not your email. Just the key. Anyone can broadcast a transaction; only you can sign with your key.
3. Economically Costly
Creating an identity costs sats (inscription fees). Making attestations costs sats (stake transfer). This economic cost prevents spam and Sybil attacks.
4. Rebuildable
Any explorer database is just a cache. Drop it and rebuild from the blockchain. The chain is the canonical source.
Architecture
┌─────────────────────────────────────────────────────────┐
│ EXPLORER LAYER │
│ Local database (SQLite/Postgres) │
│ REST API for queries │
│ Anyone can run one │
└─────────────────────────────────────────────────────────┘
│
indexes/queries
│
┌─────────────────────────────────────────────────────────┐
│ BITCOIN LAYER │
│ │
│ Inscriptions containing ATP documents: │
│ - Identities │
│ - Attestations │
│ - Receipts │
└─────────────────────────────────────────────────────────┘Two layers. That's it.
Next Steps
- Quick Start — Create your first identity
- Core Concepts — Understand the primitives
- Specification — Full technical details