Anvat / Demo

Test your codebase with Opus 4.8.

Paste any code below and run it through Claude Opus 4.8 — the model that found the 2026 Zcash ZK proof bug. Security audit, refactor, test generation, or just an explanation. Streams live in your browser using your own Anvat API key.

Your Anvat API key

Stored in localStorage on this device only. Never sent to Anvat's servers from this page — it goes directly from your browser to api.anvat.app over HTTPS.

Don't have an Anvat key yet? Sign up free — $2 credit, no card required.

1. Pick a task

Security audit

Spec-vs-implementation diff audit — same pattern that found the Zcash bug.

Explain code

Walk through what the code does, structure first, then per-section.

Suggest refactor

Concrete refactor proposals — what to change, why, with sample diffs.

Generate tests

Produces a test suite covering happy paths + edge cases + adversarial inputs.

2. Paste your code

626 / 12,000 chars

Billed at Anvat's Opus 4.8 rate: $10.50 / $52.50 per MTok (30% off list).

Demo source: open in DevTools to see the actual request. No telemetry, no server-side proxy — your key goes browser → api.anvat.app directly.

How this works

1. You paste an Anvat API key — saved to your localStorage, never sent to Anvat's marketing servers.
2. You pick a task and paste your code.
3. Your browser opens an HTTPS stream to api.anvat.app directly.
4. Opus 4.8 streams back. You see actual token cost.
5. Cancel anytime — the in-flight request is aborted cleanly.

What this demo doesn't do

• No anonymous tier. We don't front a free Anvat key for this — too easy to abuse.
• No multi-file context. This demo passes one code blob. Production audits work better with Claude Code or Cursor, which can read your whole repo.
• No history saved server-side. Open DevTools to confirm — every request is browser → api.anvat.app, nothing routed through this marketing site.
• Demo capped at 12,000 chars input to keep one run predictable. For real audits, use the same pattern via the Anvat API with no cap.

Use the same pattern in production

The system prompts in this demo are the exact templates we use internally for the spec-vs-implementation audit pattern. Copy them into your own Anvat / Claude Code setup and the workflow scales beyond this one-blob demo.

Read the Zcash walkthrough →Watch the video walkthrough Security research setup