Skip to main content

​
Why Use an SDK?

The Cred Evaluation API returns a trust score, trust tier, per-gate breakdown, and optional dynamic pricing for any wallet address. You can call it directly with fetch or httpx, but the SDK packages give you:
  • Typed responses — full TypeScript types and Python dataclasses, no parsing raw JSON
  • Framework middleware — one line to gate every route with trust checks
  • Automatic 402/403 handling — challenges and denials built in
  • Trust headers — X-Cred-Trust-Score and X-Cred-Trust-Tier set on every response
  • Dynamic pricing — trust-score-based price multipliers computed server-side

​
Available Packages

TypeScript SDK

Core client for Node.js, Deno, Bun, and edge runtimes. Zero dependencies beyond fetch.

Hono Middleware

Drop-in middleware for Hono. One line to trust-gate your API.

Express Middleware

Express middleware with req.credTrust for downstream handlers.

Next.js Middleware

Next.js edge middleware with route matching.

Python SDK

Async client and FastAPI Depends() integration.

​
How It Works

Every SDK package calls the same backend endpoint: 
POST https://validator.credprotocol.com/v1/evaluate
Authorization: Bearer cred_sk_...
The response includes:
FieldDescription
trust_score0–100 normalized composite score
trust_tiertrusted, verified, limited, untrusted, or blocked
gate_resultsPer-gate pass/fail with scores
confidence0.0–1.0 based on data availability
price_multiplierDynamic pricing multiplier (if enabled)
reputationBehavioral history from ERC-8004 feedback
challengePre-built 402 challenge body (if gates failed)
The middleware packages wrap this into framework-native patterns — Hono c.set(), Express req.credTrust, Next.js response headers, FastAPI Depends().

​
Trust Tiers

TierScoreMeaning
Trusted80–100Full access, lowest pricing. Proven track record.
Verified60–79Standard access, standard pricing.
Limited30–59Restricted access, elevated pricing.
Untrusted1–29Minimal access, maximum pricing.
Blocked0Access denied. Critical gate failure.

​
Policy Templates

Instead of configuring individual gates, use a named policy template:
TemplateGatesBest For
basicHuman check onlyBot filtering, basic API protection
standardHuman + identity verificationGeneral API protection (recommended default)
strictHuman + identity + established walletFinancial services, sensitive data
financialAll gates, tight thresholdsLending, payments, credit
reputationWeighted composite, dynamic pricingTiered access, trust-to-earn
quickHuman check, relaxed thresholdLow-stakes endpoints

​
Getting Your API Key

1

Sign up for a developer account

curl -X POST https://validator.credprotocol.com/v1/platform/signup \
  -H "Content-Type: application/json" \
  -d '{"name": "Your Name", "email": "you@example.com"}'
2

Save your API key

The response includes a cred_sk_... key. Store it securely — it is shown exactly once.
3

Set it as an environment variable

export CRED_API_KEY=cred_sk_your_key_here

​
Next Steps

Pick the package that matches your stack and follow the integration guide: