Facts you can actually trust.
Every claim cross-checked against sources on different websites, cited, dated, and confidence-scored before it goes live. Ask anything.
Sources on different websites can still trace to one study. See limits.
Featured facts
The Antikythera Mechanism used precisely cut, independently rotating gears in a system known as epicyclic gearing, a technology not otherwise known to exist in the West for another 1,500 years.
Archaeologists in Zambia found the world's oldest known wooden structure: two interlocking logs connected by a notch, dating to about 476,000 years ago.
Scientists revived a roundworm that had been frozen in permafrost for 46,000 years.
The marble tablet found in a New Orleans backyard was a gravestone for a Roman sailor.
A seaside town dealt with a giant whale carcass by using dynamite, which caused blubber dents on nearby cars.
The immortal jellyfish, Turritopsis dohrnii, can revert from adulthood back to its polyp stage when threatened by danger or starvation.
Abo Elementary School in Artesia, New Mexico was the first public school in the United States constructed entirely underground.
Saturn's moon Titan has lakes and rivers of liquid methane and ethane, making it the only body in our solar system besides Earth with stable surface liquids.
The wood frog can survive being frozen solid during winter, with up to 70% of its body water turning to ice, then thaw and resume normal activity.
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How DeepInquiry differs
Most AI-trust tools evaluate your data or your model's output and hand back a probability. That's useful. It's also not the same thing as knowing what's true. DeepInquiry sits one layer deeper: a verified fact corpus that AI systems can actually cite.
AI evaluation tools
Score model output
Statistical confidence on whether an AI answer seems correct. Runs on your data. Delivered inside a dashboard.
DeepInquiry
A verified fact corpus, served by API
Every claim cross-checked against sources on different websites, cited, dated, and tier-scored before it goes live. You get facts, not probabilities.
- We own the corpus.More than 2,700 facts and growing, each with scored source groups, set-aside of known Wikipedia mirrors and aggregators, and gold/silver/bronze verification tiers — not a service that runs on top of your data.
- Never a single website.Every published fact is backed by at least two sources on different websites, and the engine groups sources from one mapped parent company. Wikipedia, its mirrors and content aggregators are set aside when a source of another kind exists; a fact whose only sources are of those kinds is kept but cannot reach gold. Published facts have at least two source groups on different websites.
- Auditable, not opaque.Every fact response returns its sources in groups, a 0-1 score for how much the groups differ in website or mapped parent company and in kind of source (field name independence_score, a historical name), the group count, and the verification tier. Governance teams get the provenance trail they actually need.
- Built for RAG, agents, and grounded UIs.A natural upstream source of truth for any grounded AI workflow: verified facts in, higher-quality outputs out.
Others score the AI. DeepInquiry is the ground truth AI can cite.
Cryptographically verifiable
Every fact returned by the DeepInquiry API carries a CiteSig™ attestation — an Ed25519 signature over the claim, its sources, and the time it was issued. Verifiers do not need to trust DeepInquiry: they check the signature against our published signer identity and get a mathematical yes/no.
- Signer identity is public.Fetch /api/v1/citesig/signer to get the DeepInquiry DID. Cache it, hard-code it, publish it. No auth required.
- The signature travels with the claim.Every fact response includes a
citesigobject withclaim,signer,sources,issued_at, andsig. Store it, forward it, verify it later. - Tampering is detected.Change any character of the claim or any source URL and the signature fails to verify. Even we can’t rewrite a signed fact after the fact — that’s the point.
- An open protocol, not a lock-in.CiteSig is an open standard with reference implementations in JavaScript and Python. Anyone can build a verifier; anyone can become a signer.
Signed, verifiable facts in your product
One API call, one confidence score, one set of citations, one cryptographic signature. Free tier includes 500 requests/month.
curl https://api.deepinquiry.ai/api/v1/facts/random \
-H "x-api-key: $DI_KEY"
# every fact response now includes a citesig
# signature block — verify with @citesig/core