Chutes E2EE Browser Test

Small browser-native E2EE test client for Chutes. The UI is TypeScript/Vite; the protocol crypto lives in Rust/WASM.

See SECURITY.md for the browser trust model, deployment checks, and hardening notes.

Requires Node 24. Source WASM compilation also needs a stable Rust toolchain with wasm32-unknown-unknown.

Run

npm install
npm run wasm
npm run dev

Open the Vite URL, paste a Chutes API key, choose a model, and send a prompt. The key is kept in the input only; it is not stored in localStorage/sessionStorage or committed anywhere.

Performance

The app only uses speedups that preserve the E2EE protocol boundary:

• index.html preconnects to https://api.chutes.ai and https://llm.chutes.ai, with dns-prefetch fallback, so cold DNS/TCP/TLS setup can start before the first API call.
• WASM initializes on page load, before the user sends a prompt.
• Model selection drives E2EE discovery. The app warms only the selected model's chute_id.
• Warmed instance public keys and one-time nonces stay in memory, are scoped to SHA-256(apiKey) + chute_id, and expire according to Chutes' discovery TTL.
• Each nonce is consumed once. After a successful invoke, the app quietly warms the next nonce for that same key/model pair.
• Streaming responses are decrypted incrementally: each complete encrypted SSE line is authenticated and decrypted as soon as it arrives, then appended to the UI.

Security And E2EE

This is a browser client, so the browser is trusted for its own plaintext. Within that boundary, the app keeps the E2EE flow strict:

• API keys are never written to localStorage, sessionStorage, cookies, URLs, or logs.
• Fetches use credentials: "omit".
• Prompt encryption happens only after Send. The app does not pre-encrypt prompts or cache plaintext request bodies.
• Every request gets a fresh response keypair from WASM. Response keys and encrypted request buffers are zeroed after use where JavaScript/WASM exposes writable buffers.
• Nonces are model-specific, key-specific, one-time values. If Chutes rejects a nonce, the app drops the warmed data for that key/model pair and retries once with fresh discovery.
• Precompiled WASM is a portability and deployment choice, not a secrecy boundary. DevTools can inspect WASM, and plaintext necessarily exists in browser memory while being entered or displayed.
• Production uses a restrictive CSP, Trusted Types, no-referrer, nosniff, frame denial, and a narrow permissions policy. See SECURITY.md.

WASM Mode

By default, npm run wasm compiles the Rust crypto source with wasm-pack. For deploy or browser-only testing, set E2EE_PRECOMPILED_WASM=1 to use the checked-in artifacts in src/wasm/ instead:

E2EE_PRECOMPILED_WASM=1 npm run build

The helper script is also available directly:

npm run wasm:precompiled
npm run build:precompiled

CI tests precompiled mode from a clean checkout before rebuilding from Rust source. The Rust toolchain is pinned in rust-toolchain.toml; source builds can still produce different WASM bytes across host triples, so deployment uses the committed precompiled artifact.

This flag only controls whether the build re-compiles Rust or ships the checked-in WASM. It is not a browser secrecy boundary: DevTools can download and disassemble WASM, and the browser still owns the runtime, plaintext inputs, API key, and decrypted outputs.

Check

cargo test --manifest-path wasm/Cargo.toml
cargo clippy --manifest-path wasm/Cargo.toml --all-targets -- -D warnings
npm run check:precompiled
npm run build:precompiled
npm run check
npm run build
npm audit --audit-level=high

CI runs the same deterministic checks on every push and pull request. A live Chutes smoke test runs on pushes and manual workflow runs when the CHUTES_TEST_API_KEY GitHub secret is configured. Use a scoped, low-quota key for that secret.

This app needs Chutes CORS to allow https://chutes-e2ee-test.onrender.com on:

• GET /e2e/instances/*
• POST /e2e/invoke
• request headers: Authorization, Content-Type, X-Chute-Id, X-Instance-Id, X-E2E-Nonce, X-E2E-Stream, X-E2E-Path

render.yaml deploys this as the chutes-e2ee-test static site and sets the production security headers.