Utilities & AI

Source Verification API API

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

6 actionsLive JSON1,000 free creditsMCP-ready

🤖 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.

Live example

Real request and response JSON

Captured from the indexed primary action, source_url, on Jul 18, 2026, 5:19 PM UTC.

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 API does

Action	Description	Concrete use case	Key params
source_url	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.	Ops teams call source_url to get inspect a public URL for source-reliability.	url, check_archive, official_for
official_source	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.	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_claim	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.	Validation workflows call verify_claim to check whether one or more public source URLs support a factual claim.	claim, url, urls
pricing_lookup	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.	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_compare	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.	Ops teams call pricing_compare to compare current pricing across several curated providers (optionally filtered to a model subs….	providers, model
providers	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.	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"}'

import requests

r = requests.post(
    "https://api.reefapi.com/agent-source/v1/source_url",
    headers={"x-api-key": REEF_KEY},
    json={
  "url": "https://openai.com/api/pricing/",
  "official_for": "openai"
},
)
print(r.json()["data"])

const res = await fetch("https://api.reefapi.com/agent-source/v1/source_url", {
  method: "POST",
  headers: {
    "x-api-key": process.env.REEF_KEY,
    "content-type": "application/json",
  },
  body: JSON.stringify({
  "url": "https://openai.com/api/pricing/",
  "official_for": "openai"
}),
});
const { ok, data, meta, error } = await res.json();

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

What is the Source Verification API API?

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

Is the Source Verification API API free to try?

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

Do I need a Source Verification API login or account?

No login to Source Verification API 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 API 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 API use?

Source Verification API 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 API 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.

Is the Source Verification API API a Source Verification API scraper?

It is the managed alternative to a DIY Source Verification API scraper. Instead of building and maintaining your own scraper — proxies, headless browsers, captcha and constant breakage — you call one ReefAPI endpoint and get the same source verification api back as clean JSON.

Why does my Source Verification API scraper keep getting blocked?

Most Source Verification API scrapers break on anti-bot defenses, rate limits and IP bans that need rotating residential proxies and browser fingerprinting to clear. ReefAPI handles all of that for you — no proxies, no captchas, no maintenance — and returns live JSON. Blocked or failed calls are free.

docs / agent-source

Source Verification API

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.

Parameter		Allowed / range	Description
url	required	—	Public source URL to inspect (scheme optional — https:// is added). Private/loopback/metadata hosts are rejected.
check_archive = true	optional	—	Query the Wayback Machine for the latest snapshot (stale/archived signal). Default true.
official_for	optional	—	If 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.

Parameter		Allowed / range	Description
entity	required	—	Provider/entity name (free text accepted: 'OpenAI', 'claude', 'gemini', 'grok'). Resolved against the curated whitelist — see the `providers` action for the supported set.
need_type = docs	optional	pricing · docs · changelog · status · legal · model_card	Which official resource you need. Default 'docs'. Use 'all' to return every known official URL for the entity.
verify = false	optional	—	Also 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.

Parameter		Allowed / range	Description
claim	required	—	The factual claim to check against the source(s). Keep it specific (a number/quote verifies best).
url	required	—	Public source URL to inspect (scheme optional — https:// is added). Private/loopback/metadata hosts are rejected.
urls	optional	—	Up 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.

Parameter		Allowed / range	Description
provider	required	openai · anthropic · gemini · xai · openrouter · aws · gcp · azure	Curated 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).
model	optional	—	Optional model-name filter (substring, case-insensitive), e.g. 'gpt-4o', 'opus', 'gemini-2.5-flash', 'grok-4'.
limit = 40	optional	1–60	Max model rows to return.

Try in playground →

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.

Parameter		Allowed / range	Description
providers	required	—	Up to 6 curated providers (array or comma-list) from: openai, anthropic, gemini, xai, openrouter.
model	optional	—	Optional 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.

Parameter		Allowed / range	Description
provider	optional	—	Optional: return only this provider's detail.

Try in playground →

Example request · source_url

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"}'

Response shape

{
  "ok": true,
  "data": { /* the result */ },
  "meta": {
    "latency_ms": 240,
    "record_count": 12,
    "completeness_pct": 100
  },
  "error": null
}