Overview

When one AI agent buys from another, it reads terms, perhaps negotiates, and pays. The Legal Context Protocol (LCP) makes the payment prove what was agreed: the payment carries the hash of the agreement's record, so paying is agreeing to that exact record.

@integraledger/lcp is its reference implementation, for TypeScript and JavaScript. It assembles the record, hashes it, and binds the hash into payments on x402, MPP, agentic checkouts and card networks, across EVM chains, Solana, Stellar, the XRP Ledger and every other rail the rails guide lists.

How it worksCopy Anchor Link

sequenceDiagram
  participant B as Buyer
  participant S as Seller
  B->>S: request
  Note over S: assemble the ATR, hash it (H), store the bytes at a link
  S-->>B: payment challenge carrying H and the link
  B->>S: fetch the link
  S-->>B: the ATR's exact bytes
  Note over B: SHA-256(bytes) equals H, or stop
  Note over B: build the payment with H in its field, sign it
  B->>S: payment carrying H
  Note over S: H read back from the payment equals the H it issued

1. The seller assembles the record. The Agentic Transaction Record holds a format marker, a per-transaction id, the values that tie it to this payment, and whatever the parties agreed, byte for byte.
2. The seller advertises its hash. H goes into the payment challenge, beside an https link to the seller's copy.
3. The buyer compares before it signs. It fetches the bytes, hashes them, and signs nothing unless they hash to H.
4. The payment carries H. The buyer signs a payment with H in the field its protocol or rail provides: a nonce, a memo, a salt, an invoice field.
5. Anyone holding the record can match it. The seller reads H back from the payment, and on most rails from the settlement on chain.

The package fixes the bytes, the hash and where H rides. It does not decide what the record says, and it never compares amount, payee, asset, timing or payer with the record's content: that is between the parties, and the record is what they agreed.

TermsCopy Anchor Link

These pages use each term in one sense:

Where to startCopy Anchor Link

The documentationCopy Anchor Link

• Concepts explain each rule: the ATR, the ATR hash, binding, pairings, the buyer gate, refusals and vectors.
• Guides walk each flow with a program you can run: seller, buyer, channels, sessions and subscriptions, x402, MPP, agentic checkouts, rails and discovery.
• Reference is generated from the package: entry points, pairings, refusal codes, vector files and the API.

Every TypeScript program in these pages is compiled and run against the package in CI, and its output is checked against what the page shows.

For AI agentsCopy Anchor Link

The documentation site publishes llms.txt, an index of every page, llms-full.txt, every page in one file, and each page as Markdown under /md/, such as /md/getting-started.md.

Source and licenseCopy Anchor Link

The source is at github.com/IntegraLedger/integra-protocol, under the Apache-2.0 license. The buyer packages are in integra-agentic-terms, and the seller door's contract and connectors in integra-agentic-connectors.