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

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.

See docs.bankr.bot for the Bankr skill system overview.

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