Build an agent that pays for APIs with USDC on Base

The stack, layer by layer

1. 1. Agent framework

   • Lucid Agents Sato Score 71 · High

     Sato Check (v5.0.0, 2026-09-27, declared+traced): Asks for a private key or seed phrase in its setup; not yet run with planted keys.

     bunx @lucid-agents/cli my-agent · install reproduced by Sato Hub 2026-09-21 · Sato Check

   • Arbitrum Vibekit Sato Score 72 · High

     Sato Check (v1.2.2, 2026-09-29, declared+traced): No private-key read found in its setup or published code; not yet run with planted keys.

     npx -y @emberai/agent-node@latest init · install steps self-reported by the project, not reproduced · Sato Check

2. 2. Wallet & keys

   This wallet pays for every request. Set a maximum price per call and a daily budget before it holds real USDC.

   • Bankr Sato Score 87 · High

     Sato Check (v0.3.43, 2026-09-30, declared+traced+observed): Reads your key and signs locally — what a wallet does; a planted key was not observed leaving (during install and start-up in our sandbox; code paths that run later or on a trigger are not covered).

     npm install -g @bankr/cli · install reproduced by Sato Hub 2026-09-21 · Sato Check

   • Trust Wallet Agent Kit (TWAK) Sato Score 87 · High

     Sato Check (v0.20.0, 2026-09-26, declared+traced): No private-key read found in its setup or published code; not yet run with planted keys.

     npm install -g @trustwallet/cli # binary: twak · install reproduced by Sato Hub 2026-09-21 · Sato Check

3. 3. Payments

   • World AgentKit Sato Score 76 · High

     Sato Check (v0.2.1, 2026-09-26, declared+traced): No private-key read found in its setup or published code; not yet run with planted keys.

     npm install @worldcoin/agentkit · install reproduced by Sato Hub 2026-09-21 · Sato Check

   • Bankr Sato Score 87 · High

     Sato Check (v0.3.43, 2026-09-30, declared+traced+observed): Reads your key and signs locally — what a wallet does; a planted key was not observed leaving (during install and start-up in our sandbox; code paths that run later or on a trigger are not covered).

     npm install -g @bankr/cli · install reproduced by Sato Hub 2026-09-21 · Sato Check

4. 4. MCP tooling

   • BlockRun MCP Sato Score 91 · High

     Sato Check (v0.53.1, 2026-09-29, declared+traced): Reads your key and signs locally — what a wallet does; not yet run with planted keys.

     npx -y @blockrun/mcp · install reproduced by Sato Hub 2026-09-21 · Sato Check

   • Coinbase x402 Bazaar (Discovery API + MCP) Sato Score 78 · High

     Sato Check (v1.57.1, 2026-09-30, declared+traced): Reads your key and signs locally — what a wallet does; not yet run with planted keys.

     npm install @coinbase/cdp-sdk · install reproduced by Sato Hub 2026-09-25 · Sato Check

Install steps and checks

Each pick shows the first install line from its deploy spec and whether Sato Hub reproduced that install in a container or only parsed it from the project's docs. The Sato Check link under each pick opens what its code does with a key. For a fuller reading of any pick before you install, connect or pay, run Preflight.

An agent can pull this same stack, with install steps for every pick, in one call:

onchain_agent_build_plan {"goal":"an agent that pays for APIs with USDC using x402","chain":"Base"}

Server: https://satohub.ai/api/mcp, no key.

What this does not cover

• The selling side. This guide is for the agent that pays. A template that charges for an endpoint is the other half of an x402 payment, and it is not what this goal asks for.
• Which APIs to pay. Which endpoints actually answer an x402 payment request is a separate, dated record on the x402 verified page.
• Whether the API is worth paying for. A payment standard says how to pay, not what you get back.

How to read the numbers

• A Sato Score measures how open, active and verifiable a project is. It is not a safety, quality or returns grade.
• A Sato Check line describes what was read and run, with its date and its limits. A missing reading is unknown, not clear.
• Unknown means Sato Hub holds no record. It does not mean something is wrong.
• This is a build guide. It is not trading, investment or legal advice.
• Sato Hub has no token. A token using the Sato name is not ours.

Other build guides

• Build a Base trading agent that swaps USDC for ETH when a price signal fires
• Build a treasury balance monitor for Base addresses that sends alerts
• Build an agent that sends USDC on Solana as a reward when a GitHub pull request is merged