# Oracle by SaltCrate

> Verification + freshness tools for AI agents — clean web extraction, link-liveness, content-change detection, claim-vs-source checks, schema-driven structured extraction, live web search, and recurring change monitoring, exposed as paid MCP tools via Stripe Machine Payments.

MCP endpoint (streamable-http, stateless): `https://oracle.saltcrate.com/mcp`

Plain-HTTP (MPP) endpoints: `POST https://oracle.saltcrate.com/{tool}` for fetch, search,
check_link, check_change, verify, extract, monitor. JSON body, JSON result. An unpaid call
returns `402 Payment Required` with `WWW-Authenticate: Payment` challenges; retry with
`Authorization: Payment <credential>`. Discovery: `https://oracle.saltcrate.com/openapi.json`.

FREE TIER: 200 calls/hour per IP with no key, no signup, no wallet — call any tool except
`extract` directly. Start here; no credential is needed. (On the plain-HTTP routes, add
`X-Oracle-Free: 1`; MCP calls need no header at all.)
Pricing: $0.01/call via Tempo USDC; $0.50/call via card (SPT) on extract and monitor only.
No wallet? Prepaid access pass: $5 for 1,000 calls by card at https://oracle.saltcrate.com/buy — returns an `orc_…` key to send as `Authorization: Bearer`.

## Tools

### fetch
Get clean, readable text from a web page — boilerplate, navigation, and ads stripped — so you can work with the actual content. Returns the text plus title, content-type, HTTP status, and length.

### check_link
Is this URL live right now? Returns HTTP status, the redirect chain, final URL, and round-trip latency in milliseconds.

### check_change
Did this web page change since the last time it was checked? Hash-based change detection. First check reports `new`; later checks report `changed` or `unchanged`.

### verify
Does this source URL support a given claim? Returns a confidence score, matched terms, and the best supporting excerpt. Heuristic term-overlap — not semantic fact-checking.

### extract
Schema-driven structured extraction: fetch a URL and map its content into typed entities that conform to a JSON Schema you provide. Returns schema-conforming JSON (e.g. pricing, company facts, product specs, events). Requires DEEPSEEK_API_KEY.

### search
Live web search. Returns a list of {title, url, snippet} results plus which backend served them (free DuckDuckGo by default, or Brave/Serper when configured).

### monitor
Watch a URL over time — call periodically and pay per check. First call reports `new`; later calls report `changed` or `unchanged`, with changes_since_first_seen, first_seen, and last_checked timestamps for recurring monitoring.