API reference
Base URL https://api.unlob.com. Every endpoint is a GET. Authentication is an x-api-key orAuthorization: Bearer header, except where noted.
Verified 5 August 2026·API surface
Search & retrieval
Find passages, widen a result set, and fetch the one document you actually decided to read.
/searchSearchmcp: web_searchThe main query surface: returns metadata-only passage hits — url, host, title, snippet, score and world-model signals — but never the page body.
/similarSimilarmcp: similarMore-like-this: given a passage id, returns its semantic neighbours from the same embedding space the index was built in.
/browseBrowsemcp: browseQuery-free browsing: the most recent or highest-ranked passages, optionally within a single vertical.
/doc/:idGet documentmcp: get_documentFetches the full cleaned text of one passage by id — the only endpoint that returns page content.
Coverage graph
Traverse the relationships the index already computed: corroboration, authority, entity briefs, connecting paths and packed context.
/relatedRelatedmcp: relatedCoverage graph traversal: the connected neighbourhood of a passage, up to k hops — the edges are what to read next.
/corroborateCorroboratemcp: corroborateThe anti-hallucination check: how many distinct hosts independently carry a story, and which ones.
/authoritiesAuthoritiesmcp: authoritiesThe top passages on a topic ranked by graph centrality, so an agent can triage a field before reading into it.
/dossierDossiermcp: dossierA one-hop brief on an entity: where it is mentioned, which hosts cover it, and which entities co-occur with it.
/pathPathmcp: pathThe shortest chain of edges linking two passages — reasoning-path retrieval, or connect-the-dots.
/assemble_contextAssemble contextmcp: assemble_contextGraphRAG as a single call: a corroborated, story-deduplicated, trust-ranked context pack fitted to a token budget, with a reason attached to every passage.
Discovery & operations
Capability discovery, coverage transparency, account state and the probes your infrastructure expects.
/why_notWhy notmcp: why_notCoverage transparency: explains whether a URL is present in the index, was removed and why, or was never admitted.
/describeDescribeNo authA self-describing capability catalog: the filter grammar and every controlled vocabulary, so an agent can discover the query surface instead of guessing it.
/accountAccountYour tenant’s current plan, usage against quota and remaining allowance for this billing period.
/healthzHealthNo authUnauthenticated liveness probe. Returns 200 while the process is up.
/readyzReadinessNo authUnauthenticated readiness probe: 200 once the index is loaded and non-empty, 503 while it is not.
/metricsMetricsNo authPrometheus metrics: per-status request counters, a latency histogram and an in-flight gauge.
Get a key
Everything on this page works on the free tier. 10,000 requests a month, no card required.