Concord Protocol Package

TypeScript implementation of the Concord protocol core: entries, commits, and ledger containers with canonical hashing rules.

Overview

This package provides:

• Canonical data structures for Concord ledgers
• Deterministic hashing for EntryID and CommitID
• Canonical signing payloads and bytes
• Genesis commit creation
• Commit chain traversal, replay helpers, and validation

Pending entries and application state are intentionally out of scope. User management, access control, encryption policy, and networking are out of scope.

Installation

npm install @ternent/concord-protocol

Quick Start

import {
  createLedger,
  deriveEntryId,
  deriveCommitId,
  getCommitChain,
  getEntrySigningPayload,
} from "@ternent/concord-protocol";

const ledger = await createLedger({ implementation: "concord-js" });

const entry = {
  kind: "concord/user/added",
  timestamp: "2026-01-01T00:00:00Z",
  author: "author-1",
  payload: { id: "user-1" },
  signature: null,
};

const entryId = await deriveEntryId(entry);
const signingPayload = getEntrySigningPayload(entry);

const chain = getCommitChain(ledger);
console.log(entryId, signingPayload, chain);

API Notes

• EntryID excludes the signature field
• CommitID hashes the full commit structure
• Genesis commits are not replayed and contain no entries
• Canonical JSON uses lexicographic key ordering with no whitespace
• Inputs must be plain JSON values (no toJSON, no non-finite numbers)
• Hashing is SHA-256 over UTF-8 bytes with lowercase hex output

Tests

pnpm --filter @ternent/concord-protocol test

Shared vectors live in packages/concord-test-vectors.