Frequently asked questions
Short answers for agents and developers calling pay-per-call APIs. Each operation is POST-only with a fixed USDC price on Base, paid with the x402 exact scheme. An unpaid POST returns 402 payment terms before the body is validated. A request that carries payment-signature is not yet charged: settlement happens only after a successful (2xx) result. HTTP 4xx/5xx are not charged. Coverage bodies with status complete, partial, or failed all return HTTP 200 and are charged at the full listed price. Settled 2xx responses include a payment-response header; 4xx/5xx do not. For the full payment walkthrough see How it works; for product lists see the API catalog and use cases.
What is BRAINIAC.software?
BRAINIAC.software publishes pay-per-call APIs for AI agents and software workflows: sanctions screening, compliance checks, security reviews, Base chain intelligence, and more. There is no account and no API key. Each operation has a fixed USDC price on Base and is paid with x402.
Do I need an API key?
No. An unpaid POST returns HTTP 402 with x402 payment terms. After you pay the exact USDC amount on Base, retry the same request with a payment-signature header and an Idempotency-Key.
What is x402 payment?
x402 is an HTTP payment protocol. BRAINIAC uses the exact scheme with USDC on Base (network eip155:8453, asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913). Compare payTo, asset, and network with the pins on /api/v1/catalog and /.well-known/x402 — not only with what a single 402 response says about itself.
When is a call charged?
Carrying a payment-signature is not a charge. Settlement happens only after a successful HTTP 2xx result. Settled 2xx responses include a payment-response header. HTTP 4xx and 5xx are not charged and do not include payment-response. Coverage responses with status complete, partial, or failed return HTTP 200 and are charged at the full listed price. Exception: a facilitator 502 after payment-signature is SETTLEMENT_UNKNOWN — the authorization may already be settled on Base; check USDC authorizationState(payer, nonce) before re-signing.
What does a post-signature 402 or 503 say about my previous payment?
Those responses release the Idempotency-Key and include a prior-payment-attempt header with the authorization nonce and settled false or unknown. They do not include payment-response. If settled is unknown, or you received SETTLEMENT_UNKNOWN (502), read USDC authorizationState(payer, nonce) on Base before creating a new signature — re-signing a nonce that is already used can mean a second charge on another attempt.
How do I call a sanctions screening or compliance API?
Open the OFAC & UK Sanctions Screening product under Compliance in the API catalog, or start from the sanctions screening use-case page. Each operation documents its request body, USDC price, and sources. Outputs are prechecks for human review, not official determinations.
What MCP servers do you offer?
Streamable HTTP MCP servers wrap the same pay-per-call APIs for Claude, Cursor, and other MCP clients. Listing tools is free. Calling a paid tool uses the same x402 payment as the POST API. See the MCP servers page for catalog URLs and Cursor config.
What does status partial or failed mean?
Security and coverage responses may include status complete, partial, or failed plus missing_items. HTTP 200 with any of those statuses is charged at the full listed price. timeout and rate_limited often warrant one retry after a delay with a new Idempotency-Key; upstream_down only after the upstream recovers; not_supported never for that check.
Can I look up a previous result without paying again?
Yes. Successful coverage responses include result_id. GET /api/v1/results/{result_id} returns the stored JSON without re-running checks. It is free, expires after about 24 hours, and returns 404 RESULT_NOT_FOUND when unknown or expired — not a 402.
Which APIs should I start with?
Browse the API catalog by theme (Compliance, Security, Crypto / Base, Operations, and more), or read the agent use-cases hub for sanctions screening, x402 payments, MCP, token security, and construction reporting entry points with links into each product.
Who do I contact for support?
Email support@brainiac.software. Include the service name, operation path, HTTP status, and Idempotency-Key (not the payment signature). See Contact Us for what to send and what to omit.
Still stuck? Contact Us or browse MCP servers.