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BlocksTools & Utilities
Jev Output Verifier
Jev Output Verifier
Write an answer, then show it only if Jev is at least 90% sure it actually answers the question. If not, rewrite once.
Use this when you want your own code to hold the confidence floor a draft answer must clear before display, with at most one retry on a miss.
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Problems solved
Technical challenges this implementation handles out of the box.
- Gate a generated draft with one boolean probability
- Regenerate once when the draft misses the ship floor
- Keep the verify threshold in application code
Use cases
Products and workflows this pattern is designed to support.
- Answer verification before showing a draft
- One-retry regeneration floors
- Teaching Jev boolean probabilities on generated text
Compare with
Similar patterns, and when each one is the better fit.
Jev Loop BreakerUse this when an agent looks up facts step by step and you want the stop threshold in your own code, not left to the model to decide.
Jev Best-of-N JudgeUse this when you already have several candidate replies to one prompt and need one chosen, or none at all if the pick is too close to call.
Jev Composite ScorecardUse this when one blended rubric hides which factor failed and you want atomic Jev scores merged into a single weighted score in your app.
Jev Infinite FAQUse this when FAQ visitors ask in their own words and you want to open the matching canned answer or add a grounded answer as a new row.
Setup
Requirements, wiring steps, and what this pattern adds to your project.
Getting started
Pick how you want to pull this pattern in. Then wire env vars and routes the same way.
- 1
Download → Next.js app
Use Download → Next.js app in the preview toolbar. You get a zip scaffold (Pro downloads rewrite preview `/view/.../api/*` paths to `/api/*` automatically).
- 2
Extract the zip and install dependencies
Unzip the archive, then run `pnpm install` (or npm / yarn) in the project folder.
- 3
Fill .env.local
The download includes .env.local placeholders when needed. Add real values for: AI_GATEWAY_API_KEY.
- 4
Customize the agent and tool files
Adapt prompts, tools, and stop conditions in the generated project for your product.
- 5
Run the app and open the pattern route
Run `pnpm dev`, open the setup/checklist page if present, then navigate to the generated pattern route and verify responses.
Environment variables
AI_GATEWAY_API_KEYGet key
Capabilities
AI SDK APIs
experimental_evaluategenerateTextgatewayProviders
Jev
External services
gatewayvercel-ai-gatewayUpstash
Files added
12 files
app/page.tsxapp/layout.tsxapp/api/verify/route.tscomponents/output-verifier-demo.tsxcomponents/typesafe-ai.tsxcomponents/probability-bar.tsxhooks/use-output-verifier.tslib/verify-policy.tslib/verify-questions.tslib/rate-limit.tslib/request-utils.tsREADME.md
Dependencies
7 total
npm packages
5UpstashAISDKlucide-reactNext.jsReact
Registry components
buttontextarea
Critical files
3 files
lib/verify-policy.tsPure decideVerify policy: ship only when P(ok) >= 0.90, otherwise regenerate once. Keep the threshold in application code. Unit-test with Experimental_EvaluationMockModelV4 — do not call Jev or the generator from tests.
lib/verify-questions.tsBoolean meetsCriteria question on { question, draft }. True means a concrete answer with no hedging that hides a missing fact.
verify/route.tsRate-limited generateText plus experimental_evaluate through AI Gateway. Regenerates at most once, with the failed draft and P(ok) in the second prompt. zeroDataRetention is on.
Requirements
- Complexity
- Beginner
- Setup time
- ~5 minutes
- Node
- 24+
- Memory
- 256MB
Upstash Redis for deployed demo rate limiting
