Build with logbook.

Three calls — register the agent (free), log an event ($0.001 USDC), verify any past event (free).

# install the sdk
npm install @logbook/sdk

# in your code
import { Logbook } from '@logbook/sdk';

// 1. one-time: register an identity
const identity = await Logbook.register({ displayName: 'my-agent' });
console.log(identity.did);  // did:logbook:HLMnau36uv...

// 2. log every action ($0.001 USDC via x402)
const logbook = new Logbook(identity);
const event = await logbook.log({
  action: 'swap',
  resource: '0x833589fCD6...USDC',
  metadata: { from: 'ETH', to: 'USDC', amount: '0.5' }
});

// 3. anyone can verify (free, public)
const proof = await Logbook.verify(event.id);
// { valid: true, chainLength: 1 }

For full request/response schemas, error codes, and the canonical signature algorithm, see the README on GitHub.

The official TypeScript SDK ships as @logbook/sdk. It handles canonical message serialization, ed25519 signing, x402 payment retry, and chain head caching.

For the full method-by-method reference (parameters, return types, error codes), see the SDK reference page.

Source: github.com/logbookbase/logbook/tree/main/sdk

Python and Go SDKs are on the roadmap. Until then, calls can be made directly via curl or any HTTP client — see the API reference in the repo.

• Register an agentfree
• Log an event$0.001 USDC
• Verify an eventfree
• Read agent + event historyfree

Writes settle on Base via x402. Bankr agents pay automatically; non-Bankr clients use @x402/fetch or sign the EIP-3009 transfer manually.

Logbook is shipped as a Bankr skill. Any Bankr-hosted agent can install it and start logging without writing code.

bankr skills add github.com/logbookbase/logbook-skill

After install, the agent knows when to log (trades, transfers, token launches, automated decisions) and handles the x402 payment using the agent's own wallet.

Skill source: github.com/logbookbase/logbook-skill. See docs.bankr.bot for the Bankr skill system overview.

Logbook is open source under MIT. Issues, PRs, and questions welcome.