SIGNED·TIMESTAMPED·SOURCE-LINKED·TAMPER-EVIDENT

The signed evidence layer
for what goes in your body.

Ask whether any ingredient claim holds up. One call returns a graded, sourced, signed answer.

Every answer traces to peer-reviewed sources, signed at the moment of the call.

GET probara.dev/api/v1/evidence
REQUEST

  "ingredient": "ashwagandha",
  "outcome":    "sleep",
  "dose_mg":    600,
  "attest":     true
RESPONSE 200 OK

  "grade":       "B",
  "dose_match":  "MATCH",
  "pmids": [32818573, 34559859],
  "studies":     14,
  "verified":    true,
  "attest": 
    "id":    "pbr_ashw_sl_v3",
    "ts":    "2026-07-02T04:00Z",
    "hmac":  "d4f1…a93c"
    
  

Send a claim. Get receipts.

Send an ingredient and the claim you want to stand behind. Probara grades it against the published literature and returns a signed attestation you can show anyone.

01

Send the ingredient × outcome pair

Send the ingredient name, target outcome, and your labelled dose. Authenticate with your API key.

02

Receive a GRADE-rated evidence card

GRADE certainty (A–D), dose-match verdict, study count, N-total, and PMID-cited summaries: all structured JSON.

03

Verify the HMAC attestation

Recompute the HMAC locally. Match means the card is byte-for-byte identical to the server output (tamper-evident by design).

Signed Timestamped Source-linked Tamper-evident

Every grade shows its work.

No black-box score. Each grade opens to the studies behind it: design, sample size, dose match, and the signature that locks it.

Evidence Card GRADE B
Ashwagandha × Sleep
ASHWAGANDHA · 600 mg/day · DOSE MATCH
Studies
14
Effective range
300-700 mg
Certainty
B moderate
Dose match
MATCH
PMID 32818573 RCT Langade 2020 · parallel ✓ verified
PMID 34559859 RCT Cheah 2021 · crossover ✓ verified
PMID 37543151 RCT sleep RCT 2023 · parallel ✓ verified
HMAC-SHA256 pbr_ashw_sl_v3 2026-07-02T04:00:00Z Verify ↗

Claim what you can defend.

The FTC expects competent, reliable evidence behind every health claim. Probara hands you the paper trail before you print the label.

Traceable provenance. Every card names the PMID, corpus version, and query parameters that produced it.

Reproducible. Same ingredient, outcome, and corpus version returns the same card. Your auditor can replay the call.

Tamper-evident HMAC. The signed attestation proves the card is byte-for-byte identical to the server output. Nobody touched it.

Millions of sources, one endpoint.

34M+

PubMed citations indexed in the evidence corpus

SOURCE: NLM / PubMed public catalog. Illustrative of index depth at launch.

Verifiable, not trust-me.

Every attestation is signed, timestamped, and checkable at a public URL. You don't have to trust us. You can verify.

TLS 1.3 + HMAC attestation

All API traffic is TLS 1.3 encrypted. Every evidence card is HMAC-signed and verifiable: recompute with your shared API key to confirm integrity.

AES-256 at rest · TLS 1.3 in transit

Immutable audit trail

Every query logs the corpus version, query parameters, and attestation ID. Your compliance team has a full reconstruction path.

Append-only log · 90-day retention

Versioned corpus, reproducible results

The corpus version is embedded in every card response. Pin a version, replay any query, get the identical card. No moving targets.

Corpus v3 current · changelog public

Ship claims you can stand behind.

Get a key and make your first signed call in under five minutes.

Get your free API key FREE TIER · NO CARD REQUIRED

Free tier

Get your free API key.

10 attested evidence cards per month. No credit card required. Your key arrives by email with a quickstart link.

Where we send your free API key and quickstart link.

Free tier: 10 attested evidence cards per month. No call required. Upgrade anytime at api-pricing.

Research tool. Not legal or regulatory advice.