ViewSpec is the compiler between your agents and your UI. Agents commit to meaning — nodes, bindings, motifs. ViewSpec owns the renderer output: deterministic, with no model call at render. HTML and React compile locally; the hosted API adds SwiftUI and Flutter.
An IntentBundle is a semantic contract, not a template. The compiler turns it into an interface the same way every time — and can prove what it did.
Same intent, same bytes, same hash — on every machine, every run. No model in the render path, so output never drifts.
One bundle emits html‑tailwind and React locally; the paid API delivers four targets with hashes, provenance, and diagnostics.
Every element carries its lineage. Trace any pixel to the binding and raw data — and prove the artifact phones home to nobody.
An agent describes a group of things. You decide whether it’s a table, a dashboard, or a gallery. Flip it — same four bindings, three renderings.
Pick an aesthetic profile. The compiler re‑derives density, emphasis, rhythm, and grid from a single token — a lookup, not a redesign. This whole page re‑themes with it.
Turn on Inspect (top‑right, or press i) and every element on the page shows the IR address it came from. Click, tap, or hover a chip below to trace one all the way back to the data.
Agent-native app compiler
Agents commit to meaning — nodes, bindings, motifs. ViewSpec compiles the UI, the state reducer, replay checks, and shell proof. Deterministic, and no runtime LLM.
| State IR | interactive_state_v0 writes state_reducer.ts and reduceViewSpecState. |
|---|---|
| Aesthetic Profiles | Eight compiled projections from one semantic graph. |
| Proof Pipeline | state_replay_assertions plus viewspec prove-app --with-shell. |
| Semantic Correction | Source-bound previews and applied receipts keep changes traceable. |
| Portable Surfaces | html-tailwind and React locally; four integrity-checked targets through the paid API. |
| describe | Author IntentBundle or AppBundle JSON. |
|---|---|
| validate | viewspec validate-intent fails closed on drift. |
| prove | viewspec prove --intent compiles, checks, and renders the exact artifact. |
| Free | Local SDK. Unlimited compiles, proofs, and surfaces. |
|---|---|
| Pro | 149/mo. Hosted compiler API, 10k calls per day. |
| Enterprise | Custom volume, organization sharing, and support. |
Two claims most tools ask you to take on faith. Here they’re computed on the page you’re reading.
The provenance hash is sha256 over the canonical IntentBundle. Recompute it — identical bytes, identical digest, every time.
ViewSpec’s check gate certifies an artifact makes zero cross‑origin requests before it ships. This page holds itself to the same bar — measured live:
All 10 fixed cases passed product quality on first compile with 0 critical issues, rendered at mobile, tablet, and desktop with accessibility, DOM, log, and screenshot evidence, and completed 10/10 verified semantic corrections with 10 applied receipts. Explore the retained evidence · Eight-gate result · Scorecard · Correction proof. Fixed-corpus evidence is not certification of arbitrary briefs or host apps.
Two opt-in integrations by chenglou bind declared source inventories to independently checked generated behavior in react-tailwind-app proofs.
@chenglou/freerange@0.0.1 binds every eligible state-operation occurrence to the emitted state contract, exact generated helpers, 100% function analysis, and runtime call sites.
viewspec prove-app --app viewspec.app.json --target react-tailwind-app --install --freerange --json
It does not analyze CSS, prove rendered geometry, certify arbitrary math, or certify arbitrary host apps.
@chenglou/pretext@0.0.8 preserves native DOM semantics, independently inventories every eligible text surface per route and viewport, and checks native-DOM versus Pretext line count and overflow with named Arial, sans-serif.
viewspec prove-app --app viewspec.app.json --target react-tailwind-app --install --pretext --json
It is not general typography proof, canvas-rendering proof, pixel-perfect visual regression, accessibility certification, or arbitrary-host certification.
Compose the proofs: viewspec prove-app --app viewspec.app.json --target react-tailwind-app --install --freerange --pretext --json runs both independently reported analyses and does not broaden either guarantee. Dedicated hosted E2E is configured to cover healthy proofs plus division, bounds, font, wrapping, and overflow mutation rejection on relevant changes, weekly, and by manual dispatch; this does not claim that a hosted run has completed.
The free SDK stays offline and deterministic. Hosted plans add shared compilation capacity, organization controls, and support around the same proof pipeline.
Build, compile, and prove ViewSpec artifacts locally without an account.
Hosted compile API for production agent workflows and shared team demos.
Scale ViewSpec across internal agent products with support and controls.
Pricing is intentionally simple: the compiler remains useful locally, while hosted capacity adds API volume, richer derivation, custom motifs, portable artifacts, receipts, and support.
No account, no network, no LLM key. Install the SDK, write intent, prove the output.