Provides tools for reading EVM wallet balances on the Ethereum network (and Base), enabling USDC balance snapshots for payment authorization and verification.
Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type @ followed by the MCP server name and your instructions, e.g., "@GPT55 x402 Gateway Check the current quote for the translate-canary route."
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
GPT55 x402 Gateway is the canonical buyer-owned Base USDC entry for this repository.
GPT55 is an x402 GPT API gateway: it provides an OpenAI-compatible GPT-5.6 Luna Standard result for $0.00293 USDC on Base. This is a compatible gateway, not an OpenAI-operated product. Buyers can pay one request from a browser wallet without handing over a private key, or use the quote-first agent fallback client when a wallet UI is unavailable.
The focused search topic is x402 GPT API / GPT API with USDC on Base:
one POST request, one live quote, and one response. The canonical buyer path
and complete integration guide are below.
The EVM Wallet Balance Snapshot remains available as a separate utility alternative; it is not the model product.
Canonical service entry:
Service hub: https://gpt55.558686.xyz/x402/service
Machine-readable catalog: https://gpt55.558686.xyz/x402/service.json
x402 GPT API guide: https://gpt55.558686.xyz/x402/guides/ai-agent-x402-api
Static buyer guide: https://wangletiand.github.io/gpt55-x402-gateway/x402-gpt-api-guide.html
Machine-readable summary: https://wangletiand.github.io/gpt55-x402-gateway/llms.txt
Main model route: POST https://gpt55.558686.xyz/v1/chat/completions/standard
Standard quote: $0.00293 (2930 atomic USDC units) on Base eip155:8453
Browser checkout: https://gpt55.558686.xyz/x402/service?checkout=standard-chat
Wallet alternative: https://gpt55.558686.xyz/x402/service?checkout=evm-wallet-balance
Key Pack upgrade: https://x402-key.558686.xyz/x402/checkout
MCP endpoint: https://gpt55.558686.xyz/mcp
For the exact browser-wallet, Base MCP, agent fallback, receipt, and directory verification sequence, see docs/demand-first-checkout.md.
When validating a buyer-owned wallet or x402 client, start with the deterministic translate settlement canary before buying a model call or a larger pack:
Buyer guide: https://gpt55.558686.xyz/x402/translate-first-purchase
Paid route: POST https://gpt55.558686.xyz/v1/tools/translate
Quote-only command: ROUTE_ID=translate-canary MAX_USDC=0.00293 node first-payment-client.mjs
The client is quote-only by default. It verifies the live amount, Base network, USDC asset, merchant address, and same-request retry contract before an operator explicitly opts into payment. A successful canary is the smallest real payment test; Standard chat is the next step for a useful GPT-5.6 Luna response.
Related MCP server: Blocksize Market Data
The buyer client is quote-only by default. Its local policies pin the exact URL,
HTTP method, amount, Base network, canonical Base USDC contract, and merchant
address for both Wallet and Standard. Remote catalogs are discovery metadata only.
The client does not sign or pay unless the operator explicitly sets
PAY_REAL_X402=1 and provides a wallet key in the operator-controlled process.
Never paste a private key, seed phrase, payment header, API key, or exchange credential into a website, chat, issue, log, or remote service.
git clone https://github.com/wangletiand/gpt55-x402-gateway.git
cd gpt55-x402-gateway
npm install
ROUTE_ID=standard MAX_USDC=0.00293 npm run first-payment:quoteThe command remains quote-only unless real payment is explicitly enabled.
Generated evidence files and .env files are ignored by Git.
The live quote is authoritative immediately before any payment. For an
OpenAI-compatible request, send the same JSON body to
/v1/chat/completions/standard after the x402 client returns a valid paid
retry. The public service hub includes the browser-wallet flow and a link to
the agent fallback client.
npm install
npm test
npm startThe wrapper exposes one local read-only directory tool. It does not proxy MCP tool calls, custody funds, store wallet keys, or execute payments.
This public repository intentionally contains only the maintained runtime wrapper, buyer safety client, tests, and concise documentation. Operational logs, payment evidence, wallet files, credentials, internal channel ledgers, and bulk submission automation are excluded.
For security reports, follow SECURITY.md. Do not include secrets or wallet material in a report.
Licensed under the MIT License.
This server cannot be deployed
Remote MCP for Living Stack offer discovery and buyer-authorized checkout preparation.
Read only x402 catalogue: payability verdicts, prices, drift, host status, signatures. No wallet.
Metered MCP tools: free discovery over MCP; per-call execution settled in USDC via x402 v2.
Discover machine-payable APIs, probe x402 payment terms, and run seller operations. Non-custodial.