feat: add BasePay action provider — gasless USDC, batch pay, escrow, subscriptions on Base Mainnet

[osr21]

Summary

This PR adds BasePay as a community action provider for AgentKit, giving AI agents five USDC payment primitives on Base Mainnet with no additional dependencies.

Actions added

Action	Description
basepay_send_usdc	Direct USDC transfer (agent pays ETH gas)
basepay_send_usdc_gasless	EIP-3009 relay — no ETH needed by the agent
basepay_batch_pay_usdc	Pay up to 200 recipients atomically
basepay_create_escrow	Time-lock USDC for a beneficiary
basepay_subscribe	On-chain recurring USDC payment

How gasless works

The agent signs an EIP-3009 TransferWithAuthorization typed message (no on-chain tx). The BasePay relay submits it to USDC.transferWithAuthorization(), paying the ETH gas. This means agents can send USDC with zero ETH balance — a critical unlock for autonomous agent wallets.

Verified contracts (Base Mainnet)

Contract	Address
BatchPayV2	0xe40d…c68
EscrowV2	0x1eb2…499
SubscriptionManagerV2	0x1019…421

Usage

import { AgentKit } from "@coinbase/agentkit";
import { basePayActionProvider } from "./action-providers/basepay";

const agentKit = await AgentKit.from({
  walletProvider,
  actionProviders: [basePayActionProvider()],
});

Or via the standalone npm package:

npm install basepay-agentkit @coinbase/agentkit viem zod

import { basePayActionProvider } from "basepay-agentkit";

Self-hosting the relay

The relay is open-source (github.com/osr21/basepay) and requires only a funded EOA (ETH on Base) to operate. Configurable via basePayActionProvider({ relayUrl: "https://your-relay.example.com" }).

No new dependencies

The provider uses only packages already in the AgentKit dependency graph (viem, zod). The relay call uses native fetch.

---

Live dApp: https://base-pay.replit.app
npm package: https://www.npmjs.com/package/basepay-agentkit
Contracts + source: https://github.com/osr21/basepay

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 1 Sum 2

[osr21]

Hi @murrlincoln 👋 — I've just pushed a unit test file (basepayActionProvider.test.ts) to bring the PR in line with the pattern used by other action providers (e.g. basename).

What the tests cover:

• Schema validation for all five action inputs (valid, invalid address, out-of-range values, edge cases)
• sendUsdc — success path + error handling
• batchPayUsdc — approve+batchSend when allowance is zero, approve-skip when sufficient, revert error
• createEscrow — approve+create, unlock-duration label, error path
• subscribe — approve+subscribe, weekly/monthly interval labels, error path
• sendUsdcGasless — EIP-3009 typed-data signing, relay success, missing signTypedData, relay error, relay fetch throw

There's also been active design discussion happening in issue #1141 around the policy hook extension — six external contributors have weighed in with concrete specs. Happy to address any review feedback quickly. Let me know if anything else is needed before merge!

[Cobra-bit-prog]

If the wallet already signs Base USDC for agents — check the payee first:

Can I pay this address? ok · new · warn · sink.
First 5 free. Then $0.10 USDC per look.
Packs lead: 20 looks $0.20 · 100-address $0.15 · stamp ticket $0.05.
Take this ticket or we do not take your USDC.
Agents pay themselves. No inbox.
Pays: Base USDC + Solana USDC.

https://agent-control.net/llms.txt
https://agent-control.net/api/v1/meter/pricing
https://agent-control.net/api/v1/mcp
https://agent-control.net/.well-known/mcp.json