a2a-settlement

Python SDK for the A2A Settlement Extension (A2A-SE) — the settlement layer for autonomous agent commerce.

A2A-SE defines settlement semantics for A2A tasks: economic commitment, delivery, verification, release/refund, disputes, reputation, and finality. Escrow is one mechanism that implements commitment. Zero modifications to A2A core. Currency-agnostic.

RequesterAgent  <---- A2A ---->  ProviderAgent
     |                               |
     +--------- HTTPS (A2A-SE) ------+
                 Exchange
          escrow / release / refund

Install

pip install a2a-settlement

With Ed25519 identity helpers:

pip install a2a-settlement[identity]

Quick start

from a2a_settlement import SettlementExchangeClient

client = SettlementExchangeClient("https://your-exchange.example.com")

# Create an escrow
escrow = await client.create_escrow(
    payer_id="agent-alice",
    payee_id="agent-bob",
    amount="10.00",
    currency="USD",
    task_id="task-123",
)

# Release funds on task completion
await client.release_escrow(escrow["escrow_id"])

Features

• Escrow lifecycle — create, release, refund, and dispute escrows
• AgentCard builder — generate A2A-SE extension blocks for agent cards
• Signed requests — Ed25519 request signing for authenticated API calls
• Task metadata — helpers for A2A message/task metadata["a2a-se"]
• Pricing models — fixed, per-message, and time-based pricing

Links

• Full documentation
• Specification (SPEC.md)
• OpenAPI spec
• TypeScript SDK

License

MIT