@tryengrave/verify

A standalone, offline verifier for Engrave proofs. Give it a proof and a pinned public key; it recomputes the entire chain and tells you true or false — with no network call and no trust in Engrave. Runs in Node, Bun, Deno, Cloudflare Workers, and the browser.

npm install @tryengrave/verify

Why this exists

The whole value of Engrave is that you don't have to trust it. A server that answers "verified": true is just vouching for itself. This package hands verification to you: it re-derives the entry digest, walks both Merkle paths, recomputes the transaction hash, and checks the Ed25519 signature over the tree head — locally.

If this returns true, the event existed, in that order, unaltered. If Engrave ever forked or rewrote history, the math fails here, on your machine.

Usage

import { verifyDualInclusion, verifyExportPack } from "@tryengrave/verify"

// Verify a single entry's dual inclusion proof against a pinned key
const result = verifyDualInclusion(proof, pinnedPublicKey)
if (!result.ok) throw new Error(`failed at ${result.step}: ${result.detail}`)

// Verify a whole evidence pack offline (e.g. an export handed to an auditor)
const pack = verifyExportPack(exportJson, pinnedPublicKey)

API

• verifyDualInclusion(proof, key) — entry → transaction root → signed tree head.
• verifyConsistency(proof) — a later tree is an append-only extension of an earlier one.
• verifyAlhChain(...) — the accumulator-linked-hash chain across transactions.
• verifySth(sth, key) — the Ed25519 signature over a signed tree head.
• verifyExportPack(pack, key) — verify an entire self-contained evidence pack.

Every function returns a Result-style { ok, step, detail } so a failure tells you exactly which check broke.

Part of Engrave — immutable audit evidence, verifiable by anyone. · Docs · MIT