Choose the smallest correct API for the agent’s actual job.
ScriptMasterLabs' buyer guide routes seven common agent jobs to the smallest correct API: known source → extraction, unknown source → research, one market reading → quote, corroboration → verification, provider doubt → trust check, and currency math → European Central Bank reference rates — with a standing rule to inspect current runtime terms before any payment is authorized.
The fastest way to waste agent budget is to buy a broad platform for a narrow task—or to treat a cheap single reading as verified evidence. This guide routes seven common jobs by what the caller actually needs, what can be checked before spend, and what each product deliberately does not claim.
Compare web APIs by job, output and purchase unit
Choose URL-to-Markdown for a known public page, structured extraction for JSON, or web research to discover sources. The free contracts linked below publish current readiness; inspect the execution route’s fresh payment challenge before authorizing spend.
| Job | Product / output | Published unit price | Free contract |
|---|---|---|---|
| Read a known URL | URL-to-Markdown / Markdown | 0.001 USDC per accepted read | Reader contract |
| Extract a known page | Web Extract / structured data | 0.005 USDC per accepted extraction | Extraction contract |
| Find unknown sources | Web Research / search plus source evidence | 0.003 USDC displayed per one-shot | Research contract |
For JavaScript rendering, login-required pages or whole-site crawling, evaluate a browser or crawling platform. These narrow public-page APIs are not substitutes for those capabilities.
Evaluate before you integrate
- Check the contract and supported inputs.
- Use the free preview where available; reject missing or irrelevant evidence.
- Inspect the exact payment challenge and enforce your own budget.
- Verify the returned output and settlement receipt separately.
curl -i 'https://squeezeos-api.onrender.com/api/web/reader-info'
This contract request is free and sends no payment signature. compare URL-to-Markdown options, compare Tavily alternatives for web search, or choose an MCP by capability.
Which API fits when I know the URL and need readable model context?
URL to Markdown API is the narrow choice: one public HTTPS URL in, compact text/markdown out after accepted delivery.
Best when: known source, RAG/context ingestion, no separate scraper account, pay-per-read economics.
Do not choose it when: JavaScript execution, authenticated pages, clicks/forms, whole-site crawling, or advanced browser anti-bot handling is required. Those belong on a browser/rendering platform.
Which API fits when I know the URL but need structured extraction?
Web Scraping API for AI Agents is the structured one-page extraction job. It is distinct from the simpler Markdown reader.
Best when: the agent needs clean structured public-web extraction rather than only Markdown.
Do not choose it as a proxy fleet, private-network fetcher, authenticated browser session or whole-site crawler.
Which API fits when I do not know the source yet?
Web Research API combines live search with safe source extraction so the result is grounded in discoverable sources instead of synthetic URLs.
Best when: the question is “find evidence,” not merely “read this URL.”
If the source is already known, route down to URL-to-Markdown or Web Extract instead of paying for search you do not need.
Which API should I call when I need one stock reading?
Stock Quote API / Quick Quote asks for one US equity ticker and returns the latest available real provider-backed price and volume reading after accepted delivery.
Choose it for: lightweight checks, alerts and agent routing.
It is not a brokerage feed, execution API, or guarantee of exchange-native realtime data.
Which API gives stronger market evidence than a single quote?
Truth Verify / Fact Verification API is for corroboration: available independent provider readings, disagreement metrics and proof metadata.
Choose it when: the downstream action deserves multiple readings rather than one quote.
It verifies ticker market-data evidence. It is not a universal internet fact-checking oracle.
What should I check when I am unsure whether to trust the provider itself?
Provider Trust moves the question up one level: inspect identity, runtime and payment-surface evidence before an unfamiliar provider is allowed into a tool/spend policy.
Choose it before connection or spend when the source/provider is the uncertainty.
Evidence reduces uncertainty; it is not a universal safety certification. Missing evidence stays unknown.
Which API normalizes money values across currencies?
Currency Conversion API / FX Convert uses European Central Bank reference-rate data for deterministic pricing/reporting normalization.
Choose it for: budgets, vendor-price comparison, reporting and machine-commerce normalization.
Reference-rate calculation is not executable bank/broker FX and does not move assets.
How does SML compete differently from conventional APIs?
SML competes differently from conventional APIs: many conventional APIs optimize around accounts, API keys, monthly plans or broad platform bundles, while SML’s narrow x402 jobs optimize around a different machine-commerce workflow: inspect first → receive fresh terms → caller applies spend policy → authorize → verify settlement → accept delivery.
That difference is only useful when the narrow SML job actually fits. A free API, browser-rendering platform, full market-data subscription or general-purpose fact checker can be the better tool when its capabilities match the task better. The routing rule is correctness before capture.
What are the payment and failure terms?
Canonical SqueezeOS paid surfaces currently use x402 v2, Base mainnet eip155:8453, Base USDC and canonical payTo 0xc29185fa176357612f3194735753e520e91adc46. Exact terms must come from the fresh target PAYMENT-REQUIRED challenge.
A 402 challenge is not a purchase. A signature is authorization, not settlement. Where a route declares a no-charge failure boundary, missing real evidence should not be converted into a fabricated paid response.
Where is the machine-readable decision matrix?
Agents can retrieve the same routing logic directly from /.well-known/agent-api-buyers-guide.json, then resolve exact endpoint truth from the linked live contract/OpenAPI.
Related: Agent API evidence hub · Buyer-intent authority · Product-intent authority · Live OpenAPI
Agent API buyer questions
Which API fits a known public URL?
Use URL-to-Markdown for readable text or Web Extract for structured output. Check the free contract before making a paid request.
Which API fits a question without a known source?
Web Research combines search and extraction. A source URL is evidence to inspect, not proof that every claim is correct.
Can I inspect the price without paying?
Yes. An unsigned request can return HTTP 402 payment requirements. A challenge alone does not authorize a payment.
Are these browser automation tools?
No. Use a suitable browser platform for JavaScript rendering, login-required pages or interactions.
Does a published price prove successful delivery?
No. Verify readiness, payment terms, settlement evidence and accepted output as separate stages.
Claim receipts
| Claim | Evidence | Checked |
|---|---|---|
| The API guide distinguishes reading, structured extraction and source discovery. | Machine-readable buyer guide | 2026-10-26 |
Updated 2026-10-26: added a job/output/price comparison and free evaluation steps.