How Kynva works

Kynva is a deterministic design engine. The same input always produces byte-identical pixels. That property — determinism — is what makes the API safe to use in production pipelines, A/B systems, and CI.

The pipeline

Brief  ──►  Compile  ──►  Spec  ──►  Render  ──►  Pixels
 (intent)   (decisions)  (frozen)   (no choices)  (PNG/MP4/...)

Stage	What it does	What it doesn’t do
Brief	Captures user intent — copy, mood, audience, brand.	Doesn’t specify layout, type sizes, or color values.
Compile	Resolves intent against your BrandKit and the design system. Every choice is pinned.	Doesn’t render pixels.
Spec	Frozen JSON contract — colors as hex, fonts as IDs, positions in px.	Has no free variables. Identical Specs render identically.
Render	Pure transformation from Spec to pixels.	Makes no design decisions.

What this means for you

Reproducibility — same input, same output

A Spec is content-addressable. If you keep the Spec, you can re-render the exact pixels months later. There are no model temperature surprises.

Explainability — see every decision

Every compile step writes a decisions log: why this font, why this color, which fallback fired. Audit trails come for free.

Composition — branch and iterate cheaply

Drafts are versioned. Branch a Draft, tweak the brief, recompile. The expensive part (render) is skipped until you preview.

Safety — the compiler enforces brand

Style-lock rules in your BrandKit are enforced at compile time. If a brief asks for a color that violates the lock, the compiler rejects it with STYLE_LOCK_VIOLATION — before any pixels render.

The API surface

One canonical endpoint, two modes:

Sync preview

POST /api/v1/facade/generate   { "operation": "preview" }   → 200 + outputs

The response carries the rendered image URLs. Best when someone is waiting.

Async render

POST /api/v1/facade/generate   { "operation": "render" }    → 202 + job
GET  /api/v1/facade/render-jobs/{job_id}                     → status poll

Consume the job via webhooks, the status poll, or the SSE stream. Best for pipelines and batches — see the async guide.

Signed image URLs — the shortcut

POST /api/v1/generate/sign        → signed URLs (batch ≤100)
GET  /api/v1/generate/{template}  → 302 to the rendered PNG

URLs that render on first fetch and cache forever. Built for OG images and no-code embeds — no Authorization header needed at fetch time.

What you’ll meet across every endpoint

Authentication

Authorization: Bearer kyn_live_... on every request.

Idempotency

Idempotency-Key: <uuid v4> on every POST mutation.

Versioning

X-API-Version: 2026-01-01 pins the response shape.

Rate limits

Tiered per endpoint category, surfaced in headers.

​The pipeline

​What this means for you

​The API surface

​Sync preview

​Async render

​Signed image URLs — the shortcut

​What you’ll meet across every endpoint