@tryengrave/client

The official isomorphic SDK for Engrave — record tamper-evident events, wrap agent runs, and verify proofs locally by default. Runs in Node, Bun, Deno, Cloudflare Workers, and the browser.

npm install @tryengrave/client

Quickstart

import { Engrave } from "@tryengrave/client"

const engrave = new Engrave({ apiKey: "ek_live_…" })

// 1 — record an event, get a receipt
const receipt = await engrave.record({ key: "evt/order/1001", value: JSON.stringify({ amount: 250 }) })

// 2 — verify it, in THIS process, with no trust in the server
const result = await engrave.verify(`tx:${receipt.tx_id}/0`)
if (!result.ok) throw new Error(`verification failed at ${result.step}`)

verify() fetches the proof material and recomputes the entry digest, both Merkle paths, the transaction hash, and the Ed25519 signature on your side. Pass { trustServer: true } only if you explicitly want the server's word for it — the default doesn't.

Fork detection

Every response carries the signed tree size and root. The client tracks them and surfaces a fork the moment the server's history diverges from what you've already seen — pin the tenant public key (publicKey option) to make the first read trustless too.

What you can do

• Records & reads — record, get, history, tx, search, state, usage
• Proofs — proofInclusion, proofConsistency, verify, publicKey
• Agent runs — runStart, runSpan, runClose, trace (a hash-linked trace of every step an agent took)
• Evidence — requestExport, downloadExport, erase (crypto-shred a value while its proof survives)
• Keys — createApiKey, listApiKeys

Auto-instrument your model calls

If your agent calls OpenAI or Anthropic directly, wrap the client once — every model call becomes a verifiable inference span (prompt/completion hashes by default, full text with captureContent). Streaming is handled; behaviour is byte-identical and recording never blocks.

import OpenAI from "openai"
import { startRunSession } from "@tryengrave/client"
import { instrumentOpenAI } from "@tryengrave/client/openai"

const run = await startRunSession(engrave, "triage ticket #4471")
const openai = instrumentOpenAI(new OpenAI(), run)     // ← every call engraved
await openai.chat.completions.create({ model: "gpt-4o", messages })
await run.close()

@tryengrave/client/anthropic exports instrumentAnthropic for Claude the same way.

Options

new Engrave({
  apiKey: "ek_live_…",
  baseUrl: "https://api.tryengrave.com", // default
  publicKey: "…hex…",                    // pin the tenant key → trustless first read
})

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