integrate-agentkit

Integrate AgentKit

Use this skill for end-to-end server-side integration work with @worldcoin/agentkit.

Start by clarifying the integration

If the developer has not already answered these, ask before choosing an implementation:

1. Which access mode do they want: free, free-trial, or discount?
2. Which payment network should the protected route use?
3. Do they control the facilitator path, or are they using a hosted facilitator?
4. Do they also need agent registration, or only request-time verification?

Default recommendation

For most production integrations:

• Put paid routes on whichever network the developer's facilitator already supports (commonly World Chain eip155:480 or Base eip155:8453).
• Leave AgentBook lookup alone — createAgentBookVerifier() always resolves against the canonical World Chain deployment. The developer does not need to think about which chain the registry lives on.
• Start with free-trial unless the developer explicitly wants free or discount.
• Only choose discount when you can wire hooks.verifyFailureHook into the facilitator flow you control.

Key pieces

• x402 resource server: the protected HTTP route and 402 challenge flow
• facilitator: verifies and settles payment payloads; required for discount
• AgentKit extension: adds the CAIP-122 challenge and verifies the signed agentkit header
• AgentBook: on-chain registry on World Chain that maps the agent wallet to an anonymous human ID. Lookup is always against World Chain regardless of the payment chain — the caller side is chain-agnostic.
• storage: per-human usage tracking for free-trial and discount
• registration path: separate from request-time verification; use npx @worldcoin/agentkit-cli --llms if the developer also needs registration help

Workflow

1. Read ../../x402/DOCS.md first. It should be the primary integration playbook.
2. Confirm exported APIs in ../../core/src/index.ts and ../../x402/src/index.ts before adding imports.
3. Prefer the hooks-based path:
   • declareAgentkitExtension
   • agentkitResourceServerExtension
   • createAgentkitHooks
   • createAgentBookVerifier
4. If the payment network is World Chain (eip155:480), add a custom ExactEvmScheme().registerMoneyParser(...) for World Chain USDC. Do not assume the server scheme has a working default stablecoin for World Chain.
5. Call createAgentBookVerifier() with no arguments in the common case. Pass rpcUrl or contractAddress only for custom World Chain endpoints or non-canonical deployments.
6. If the mode is free-trial or discount, add persistent AgentKitStorage. InMemoryAgentKitStorage is only for demos.
7. If the mode is discount, wire hooks.verifyFailureHook into the facilitator. Without it, discounted underpayments will fail verification.
8. Verify the whole path end-to-end:
   • 402 response includes the agentkit extension
   • registered agent gets the intended behavior
   • unregistered agent falls back to normal payment
   • replay protection and storage behavior work as expected

Ground rules

• Prefer the hooks-based integration unless the user explicitly needs the low-level flow.
• Use ../../x402/DOCS.md as the primary reference for examples and mode behavior.
• Do not introduce any "pin AgentBook to chain X" language — lookup is always against the canonical World Chain deployment. The payment chain and the AgentBook lookup chain are decoupled on purpose, and callers should never have to think about the lookup chain.
• Do not document World Chain with bare new ExactEvmScheme() only. Include the World Chain money parser.
• Do not choose discount unless the facilitator hook can actually be registered.
• Confirm exports in ../../core/src/index.ts and ../../x402/src/index.ts before adding or documenting imports.

Constants to keep handy

• World Chain payment network: eip155:480
• World Chain AgentBook contract: 0xA23aB2712eA7BBa896930544C7d6636a96b944dA
• World Chain USDC: 0x79A02482A880bCE3F13e09Da970dC34db4CD24d1

Reference files

• Integration docs: ../../x402/DOCS.md
• Core public exports: ../../core/src/index.ts
• x402 public exports: ../../x402/src/index.ts
• Hooks: ../../x402/src/hooks.ts
• AgentBook verifier: ../../core/src/agent-book.ts
• Header parsing and verification: ../../core/src/parse.ts, ../../core/src/validate.ts, ../../core/src/verify.ts