Why this list exists

Most API directories sort by category and stop there. This one sorts by job: what an agent is trying to do, the account-based API it would reach for first, and the x402 endpoint that does the same job for a price quoted before payment. Both sides are named. Pick whichever fits the run.

Every price and slug below comes straight from the AgentUtility registry (bankr.x402.json). None of it is a guess.

Image generation

Account-based: OpenAI's Images API, Stability AI's Stable Image API, and Replicate's hosted models all work the same way: create an account, generate a key, store it in the agent's environment, get billed on a schedule even for a single test call.

x402:

  • image-generate, $0.01. Tiers: fast (z-image-turbo, default), creative (chroma), anime (wai-Illustrious), sd35 (venice-sd35). Returns a permanent fal-hosted PNG URL.
  • image-generate-pro, $0.06. Tiers: balanced (flux-2-pro, default), recraft (recraft-v4), seedream (seedream-v4), grok (grok-imagine-image), qwen (qwen-image).
  • image-generate-ultra, $0.22. Tiers: nano-banana (nano-banana-pro, Google Gemini Image 3, default), nano-banana-2, nano-banana-lite, grok-sota.

No account required on the x402 side. The 402 response carries the price before the agent commits to paying it.

Web search

Account-based: Google's Custom Search JSON API (key, daily quota), Tavily, and Exa. Tavily and Exa in particular sell "search with contents" (results plus fetched page text) as a named product, priced per credit against a monthly plan.

x402:

  • search / web-search, $0.01. Ranked Google results via Decodo: title, URL, snippet, domain, recency filter.
  • search-content, $0.05. Same search, plus cleaned page text attached to each of the top results in one call, the composite shape Tavily and Exa charge monthly credits for.

Translation

Account-based: DeepL's API (key, character quota, monthly plan) and Google Cloud Translation (key tied to a billing account).

x402:

  • translate, $0.005. 100+ languages, auto-detect source, ISO codes or language names, preserves Markdown/code/URLs.
  • translate-text, $0.01, for callers who want a plainer response shape.

Pairs into composites too: caption-translate-pack ($0.07) and the tier of domain-specific translate endpoints (contract-translate, invoice-translate, medical-intake-translate, and similar, each $0.01) that format the output for that document type instead of returning raw translated text.

Weather

Account-based: OpenWeatherMap (key, free tier capped then a paid plan) and WeatherAPI.com (key, request quota).

x402:

  • weather, $0.005. Latitude/longitude in, current conditions plus a 1-7 day forecast (temp max/min, precipitation, sunrise/sunset, UV index) and an optional hourly breakdown out. Backed by Open-Meteo.
  • city-weather, $0.01, for callers who only have a city name and don't want to geocode first.

FX / exchange rates

Account-based: exchangerate-api.com and Open Exchange Rates, both key-gated with a monthly call cap on the free tier.

x402:

  • exchange-rates, $0.002. Latest or historical rates sourced from the European Central Bank via the Frankfurter API. 30+ currency pairs, optional base currency (default USD), optional amount conversion, no commercial-use restriction.

This one isn't investment guidance. It's a rate lookup, the same public ECB feed a lot of finance tooling already reads from.

Onchain / crypto data

Account-based: Etherscan's API (key, rate limit per tier) and node providers like Alchemy or Infura (key, request-unit budget).

x402:

  • crypto-tx-explainer, $0.04. Ethereum, Base, Arbitrum, Optimism, or Polygon transaction hash in; receipt, ERC-20/ERC-721 transfers, contract addresses, fees, and a plain-English explanation out.
  • gas-price, $0.02.
  • token-balance, $0.005.

When the account-based API is still the right call

A service that generates thousands of images a day on a negotiated rate, or needs a house-tuned model we don't carry, is better served by a direct vendor contract. Same for search or translation volume big enough that a monthly plan beats per-call pricing on unit cost. x402 doesn't try to out-price a high-volume contract. It removes the account-setup step for the call an agent wasn't going to make twice anyway.

Where x402 wins

An agent that doesn't know ahead of time which provider it'll need. A one-off script that shouldn't have to hold five different vendor keys just to try five different jobs once each. A workflow where the caller wants to see the exact price in the response before it pays, instead of finding out on next month's invoice.

Full catalog: mcp.agentutility.ai for the MCP packages, or x402.agentutility.ai for direct HTTP calls against any endpoint named above.