# A2A · Integra

> A2A delivers the ATR hash and a link to the ATR with the task; the payment for the task carries the ATR hash in its own pairing.

URL: https://integraledger.com/protocols/a2a

Protocol

## A2A

Agent2Agent protocol

A2A delivers the ATR hash and a link to the ATR with the task; the payment for the task carries the ATR hash in its own pairing. [Source: lcp docs: agentic checkouts⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/guides/checkouts.md)

A2A, the Agent2Agent protocol, was developed by Google and donated to the Linux Foundation. [Source: a2a-protocol.org⁠ (opens in a new tab)](https://a2a-protocol.org/latest/) Integra is not affiliated; we read their published interfaces.

**Sources (1)**

[lcp docs: agentic checkouts⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/guides/checkouts.md)

[The protocol’s own site⁠ (opens in a new tab)](https://a2a-protocol.org) [The standard’s illustration of this protocol (LCP §C.8)⁠ (opens in a new tab)](https://github.com/legal-context-protocol/legal-context-protocol/blob/c8df26d/spec/legal-context-protocol-v1.md#c8-a2a-agent-to-agent-protocol)

### What it is

A2A is an open protocol for communication between AI agents. [Source: LCP §C.8⁠ (opens in a new tab)](https://github.com/legal-context-protocol/legal-context-protocol/blob/c8df26d/spec/legal-context-protocol-v1.md#c8-a2a-agent-to-agent-protocol)

**Sources (1)**

[LCP §C.8⁠ (opens in a new tab)](https://github.com/legal-context-protocol/legal-context-protocol/blob/c8df26d/spec/legal-context-protocol-v1.md#c8-a2a-agent-to-agent-protocol)

### Where the ATR hash rides

The ATR hash and a link to the ATR travel with the task; the payment for the task carries the ATR hash as that payment method does.

#### The standard

A2A signs nothing per transaction, so it has no place for the ATR hash in a payment. It can deliver the ATR hash and the link with the task: the package defines an A2A extension that places them in the Task’s `metadata`. [Source: lcp docs: agentic checkouts⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/guides/checkouts.md)

The payment made for the task uses its own pairing, whose record states what it proves. [Source: lcp docs: agentic checkouts⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/guides/checkouts.md)

The extension’s URI is `https://lcp.integraledger.com/a2a/legal-context/v1`. An Agent Card declares it; a client activates it in the `A2A-Extensions` header, and should check the agent echoed it back, because an agent that does not support it simply ignores it. [Source: lcp docs: agentic checkouts⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/guides/checkouts.md) · [Source: LCP §C.8⁠ (opens in a new tab)](https://github.com/legal-context-protocol/legal-context-protocol/blob/c8df26d/spec/legal-context-protocol-v1.md#c8-a2a-agent-to-agent-protocol)

### What a payment through it proves

This protocol carries no payment pairing in the package: it delivers the ATR hash and a link to the ATR.

**Sources (1)**

[lcp docs: pairings reference⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/reference/pairings.md)

The live demonstrations are not running on this site at the moment.