Looking for the overview — what this API returns, what it costs, and a call you can run without a key? See the Source Verification API page →
Utilities & AI

Source Verification API & Scraper

The Agent Source API verifies and resolves sources for AI agents as clean JSON.

6 actionsLive JSON1,000 free credits$0.67–$1.50 / 1,000 creditsMCP-ready
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🤖 Using an AI assistant? Copy this link into ChatGPT / Claude / Cursor — it reads every endpoint and parameter instantly and tells you if this API fits your use case.

The primary source_url endpoint resolves a URL (final URL, domain, accessibility, status, redirect chain), and you can find an official_source, verify a claim, look up and compare pricing, and list providers. It is built for AI agents that must cite, verify and trust the sources they use. One ReefAPI key, one shared credit pool, the standard envelope.

Reference

The curated provider whitelist, measured provider by provider

official_source and the pricing actions answer only for a fixed whitelist, which the providers action returns in full. All eight resolve official URLs, but structured pricing rows are a separate question, and the parse surface behind each provider determines whether you get rows at all. The pricing column below is what a live call returned on 2026-08-26, not what the capability flag claims.

Provider keyOfficial URLspricing_lookup measured 2026-08-26Parse surface
anthropicYes, 6 need types13 model rowshtml_proximity
geminiYes, 6 need typesRows returned, with the same model name repeating once per price tierhtml_table
openrouterYes, 6 need typesRows returned, with output rates that are not a fixed multiple of input, e.g. 0.16 in and 0.47 outjson_api
openaiYes, 6 need typespricing_available false, count 0html_proximity
xaiYes, 6 need typespricing_available false, count 0html_proximity
aws, gcp, azureYes, 6 need typespricing_available false by design, with normalization_notes explaining that model prices live in sprawling compute-SKU pagesunstructured

The six need_type values are pricing, docs, changelog, status, legal and model_card, plus 'all' to get every URL at once. Aliases are generous: 'claude', 'opus' and 'gpt-5' all resolve to their provider key. An entity outside the whitelist is not an error, it returns ok:true with matched:false, official_url null and a suggestion listing the supported keys.

Live example

Real request and response JSON

Captured from the indexed primary action, source_url, on .

Captured request
{
  "method": "POST",
  "url": "https://api.reefapi.com/agent-source/v1/source_url",
  "headers": {
    "x-api-key": "$REEF_KEY",
    "content-type": "application/json"
  },
  "body": {
    "url": "https://openai.com/api/pricing/",
    "official_for": "openai"
  }
}
Captured response
{
  "ok": true,
  "meta": {
    "api": "agent-source",
    "endpoint": "source_url",
    "mode": "live",
    "latency_ms": 4246.7,
    "record_count": 1,
    "bytes": 0,
    "cache_hit": false
  },
  "data": {
    "url": "https://openai.com/api/pricing/",
    "final_url": "https://openai.com/api/pricing/",
    "final_domain": "openai.com",
    "accessible": true,
    "status_code": 403,
    "blocked": false,
    "redirect": {
      "chain": [
        {
          "url": "https://openai.com/api/pricing/",
          "status": 403
        }
      ],
      "hops": 0,
      "redirected": false,
      "loop": false
    },
    "metadata": {
      "title": "Business Pricing | OpenAI",
      "site_name": "OpenAI",
      "description": "Discover OpenAI pricing for ChatGPT Business and APIs, with GPT token costs, enterprise features, developer plans, and AI tools.",
      "lang": "en-US",
      "canonical": "https://openai.com/business/pricing/",
      "author": null,
      "published_at": null,
      "updated_at": null,
      "og_type": "website",
      "json_ld_types": [],
      "favicon": "/favicon.ico?favicon.0w1tl_z9koc07.ico",
      "meta_robots": "index, follow"
    },
    "render_mode": "bare-dc",
    "official": {
      "provider": "openai",
      "is_official": true,
      "reason": "final domain is in the provider's official-domain set"
    },
    "freshness": {
      "updated_at": null,
      "published_at": null,
      "archive": {
        "available": true,
        "closest": "[redacted-phone]T14:56:02Z",
        "snapshot_url": "http://web.archive.org/web/[redacted-phone]/https://openai.com/api/pricing/",
        "age_days": 32
      },
      "staleness": "archived_recently"
    },
    "subcalls": [
      {
        "api": "url-resolver",
        "action": "resolve",
        "status": "ok",
        "latency_ms": 290.4
      },
      {
        "api": "web-extract",
        "action": "scrape",
        "status": "fail:TARGET_BLOCKED",
        "latency_ms": 1110.6
      },
      {
        "api": "ext:page",
        "action": "fetch",
        "status": "ok",
        "latency_ms": 1305.3
      }
    ]
  }
}
Actions

What the Source Verification API does

ActionDescriptionConcrete use caseKey params
source_urlInspect a public URL for source-reliability: reachability, canonical + full redirect chain, title/publisher/published+updated dates, language, official-likelihood, and a stale/archived (wayback) signal.Ops teams call source_url to get inspect a public URL for source-reliability.url, check_archive, official_for
official_sourceResolve the OFFICIAL URL a curated provider publishes for a given need (pricing/docs/changelog/status/legal/model_card) + why it is official (domain match + domain age via whois). Curated whitelist only.Developer tools call official_source to resolve the OFFICIAL URL a curated provider publishes for a given need (pricing/docs/changelo….entity, need_type, verify
verify_claimCheck whether one or more public source URLs support a factual claim — returns supported, contradicted, not_found, or unclear, along with the matching evidence snippet and a confidence level. Uses exact quote and number matching against the live page content. A source-evidence checker, not a general truth oracle.Validation workflows call verify_claim to check whether one or more public source URLs support a factual claim.claim, url, urls
pricing_lookupCurrent developer/LLM pricing for a curated provider, parsed live from the provider's own pricing page/API. Each row: model, input/output per-1M-token USD, source_url, last_seen_at, unit, currency, normalization_notes.Data-quality teams call pricing_lookup to get current developer/LLM pricing for a curated provider, parsed live from the provider's own pri….provider, model, limit
pricing_compareCompare current pricing across several curated providers (optionally filtered to a model substring) → normalized per-1M-token USD, cheapest-first, each traceable to its source_url + last_seen_at.Ops teams call pricing_compare to compare current pricing across several curated providers (optionally filtered to a model subs….providers, model
providersList the curated provider whitelist + each provider's capabilities (which need_types and structured pricing are supported) and parse-surface metadata. The honest denominator for official_source / pricing.Developer tools call providers to list the curated provider whitelist + each provider's capabilities (which need_types and stru….provider
Code samples

Call source_url from your stack

curl -X POST https://api.reefapi.com/agent-source/v1/source_url \
  -H "x-api-key: $REEF_KEY" \
  -H "content-type: application/json" \
  -d '{"url":"https://openai.com/api/pricing/","official_for":"openai"}'
MCP one-liner
Ask your MCP-connected assistant: call reefapi.agent-source.source_url with {"url":"https://openai.com/api/pricing/","official_for":"openai"}.
Use cases

Who uses this API and why

  • AI agents call verify_claim to check a statement against an official source.
  • Agents use source_url to resolve and validate a canonical link before citing it.
  • Pricing agents use pricing_lookup and pricing_compare to ground cost claims.
FAQ

Questions developers ask before integrating

Does a 'supported' verdict from verify_claim mean the claim is true?

No. It means the phrase and the number both appear on that page, close together. Two measured calls against the same Anthropic pricing page prove the limit: 'Claude Opus 4.1 input is $15 per million tokens' returned supported at confidence 0.9, and 'Claude Opus 4.1 output is $30 per million tokens' also returned supported at 0.9, because $30 sits in the same price row even though it is not the output rate. The payload says it plainly in its own note: this is a source-evidence check, not a truth oracle. Always read the evidence snippets, which show exactly which text was matched.

How reliable is output_per_1m_usd?

It depends on the parse surface, and the response tells you which one was used. On providers parsed with html_proximity, normalization_notes states that input is the first price found and output is inferred from a 1.5x-to-8x band, which can pick the wrong column on a page that lists cache and batch tiers side by side. Every row also carries prices_found_usd with all the nearby rates, so on a measured Opus 4.1 row you can see the full set 15, 18.75, 30, 1.5 and 75. Bill from prices_found_usd and source_url, not from the single output number.

Why does the same model appear several times in pricing rows?

Because a provider's pricing table lists one row per tier, and the parser keeps them all rather than picking a winner. A measured comparison filtered to 'flash' returned gemini-3.1-flash repeatedly, at four different input rates: 0.125, 0.25, 0.45 and 1.5 per million tokens, which are the context and modality tiers listed on that page. cheapest_input and cheapest_output pick the lowest row, so they will report the cheapest tier of a model and not its standard rate. De-duplicate on model plus price before you show anything to a user.

What happens when I ask about a provider that is not on the list?

You get an honest empty answer rather than a guess. A measured official_source call for 'some-random-startup-xyz' returned ok:true with provider null, matched false, official_url null, an empty all_sources object and a suggestion listing the eight supported keys. The disclaimer in the payload states that finding the official source for any entity on the internet is deliberately not claimed, and that the whitelist only grows with maintainer sign-off.

official_source says reachable:false but the page opens in my browser. Which is right?

The page is fine. verify:true on official_source runs a lightweight reachability probe that can report false on hosts that answer redirects unusually. A measured source_url call on the very same URL, https://openai.com/api/pricing/, returned accessible true with status_code 200 after two hops. When reachability matters, use source_url, which gives you the full redirect chain with a status code per hop.

Why did source_url return a different URL than the one I sent?

It follows the redirect chain to the end, including any locale rewrite the site performs on your request. The measured chain from https://openai.com/api/pricing/ was 308 to https://openai.com/business/pricing/#api, then 302 to https://openai.com/tr-TR/business/pricing/, which returned 200. Read final_url and final_domain rather than the URL you sent, and note that official.is_official is decided on the final domain, which is why that redirected page still scored true for openai.

The freshness block says staleness 'unknown'. What should I read instead?

It means the page published neither a date nor a usable archive snapshot. In a measured call, metadata.published_at, updated_at, title and canonical were all null, archive.available was false, and staleness fell back to 'unknown'. Modern marketing pages frequently ship no dateable metadata at all. When you need a timestamp on a price, use last_seen_at from pricing_lookup, which records when the page was actually read, rather than trying to infer the page's own age.

How do I get an official URL for AWS, GCP or Azure pricing?

Use official_source, which resolves them normally, and skip pricing_lookup for those three. A measured pricing_lookup on aws returned ok:true with pricing_available false, an empty models array, and normalization_notes explaining that model pricing there lives inside compute-SKU pages with no stable structured slice, so it is out of scope. The official pricing URL still comes back, along with why_official showing the domain match, its age in days and the registrar.

What is the Source Verification API?

Source Verification API is a ReefAPI endpoint group for source verification It returns live JSON through POST requests under /agent-source/v1.

Is the Source Verification API free to try?

Yes. ReefAPI starts with 1,000 free credits, no card required. Source Verification calls use the same shared credit balance as every other ReefAPI engine.

Do I need a Source Verification login or account?

No login to Source Verification is needed for the API response. You call ReefAPI with your x-api-key header, and the playground can run live examples before you create a production key.

How fresh is the Source Verification data?

The page example is captured from a live source_url call, and production requests fetch live data through ReefAPI rather than a static sample.

How many credits does the Source Verification API use?

Source Verification actions currently cost 1-3 credits per successful call. Failed or blocked calls are free, and all APIs draw from one credit pool.

Can I call Source Verification from an AI assistant or MCP client?

Yes. Connect ReefAPI once through MCP and your assistant can call agent-source actions with the same key, credit pool and JSON envelope used by normal REST requests.

docs / agent-source

Source Verification

Source Verification

base /agent-source/v16 endpoints
post/agent-source/v1/source_url1 credit

Inspect a public URL for source-reliability: reachability, canonical + full redirect chain, title/publisher/published+updated dates, language, official-likelihood, and a stale/archived (wayback) signal.

ParameterAllowed / rangeDescription
urlrequiredPublic source URL to inspect (scheme optional — https:// is added). Private/loopback/metadata hosts are rejected.
check_archive = trueoptionalQuery the Wayback Machine for the latest snapshot (stale/archived signal). Default true.
official_foroptionalIf set, also score whether the final URL is OFFICIAL for this curated provider (domain match).
Try in playground →
post/agent-source/v1/official_source2 credits

Resolve the OFFICIAL URL a curated provider publishes for a given need (pricing/docs/changelog/status/legal/model_card) + why it is official (domain match + domain age via whois). Curated whitelist only.

ParameterAllowed / rangeDescription
entityrequiredProvider/entity name (free text accepted: 'OpenAI', 'claude', 'gemini', 'grok'). Resolved against the curated whitelist — see the `providers` action for the supported set.
need_type = docsoptionalpricing · docs · changelog · status · legal · model_cardWhich official resource you need. Default 'docs'. Use 'all' to return every known official URL for the entity.
verify = falseoptionalAlso live-check the official URL is reachable (adds a url-resolver inner-call + latency).
Try in playground →
post/agent-source/v1/verify_claim3 credits

Check whether one or more public source URLs support a factual claim — returns supported, contradicted, not_found, or unclear, along with the matching evidence snippet and a confidence level. Uses exact quote and number matching against the live page content. A source-evidence checker, not a general truth oracle.

ParameterAllowed / rangeDescription
claimrequiredThe factual claim to check against the source(s). Keep it specific (a number/quote verifies best).
urlrequiredPublic source URL to inspect (scheme optional — https:// is added). Private/loopback/metadata hosts are rejected.
urlsoptionalUp to 5 source URLs (array or comma-list). Combined with `url`; the best-supporting verdict wins.
Try in playground →
post/agent-source/v1/pricing_lookup1 credit

Current developer/LLM pricing for a curated provider, parsed live from the provider's own pricing page/API. Each row: model, input/output per-1M-token USD, source_url, last_seen_at, unit, currency, normalization_notes.

ParameterAllowed / rangeDescription
providerrequiredopenai · anthropic · gemini · xai · openrouter · aws · gcp · azureCurated provider key (or any alias). Structured pricing is available for: openai, anthropic, gemini, xai, openrouter. aws/gcp/azure return official_source but no structured pricing (compute-SKU pages — see normalization_notes).
modeloptionalOptional model-name filter (substring, case-insensitive), e.g. 'gpt-4o', 'opus', 'gemini-2.5-flash', 'grok-4'.
limit = 40optional1–60Max model rows to return.
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post/agent-source/v1/pricing_compare3 credits

Compare current pricing across several curated providers (optionally filtered to a model substring) → normalized per-1M-token USD, cheapest-first, each traceable to its source_url + last_seen_at.

ParameterAllowed / rangeDescription
providersrequiredUp to 6 curated providers (array or comma-list) from: openai, anthropic, gemini, xai, openrouter.
modeloptionalOptional model-name filter (substring, case-insensitive), e.g. 'gpt-4o', 'opus', 'gemini-2.5-flash', 'grok-4'.
Try in playground →
post/agent-source/v1/providersfree

List the curated provider whitelist + each provider's capabilities (which need_types and structured pricing are supported) and parse-surface metadata. The honest denominator for official_source / pricing.

ParameterAllowed / rangeDescription
provideroptionalOptional: return only this provider's detail.
Try in playground →