> ## Documentation Index > Fetch the complete documentation index at: https://docs.kynva.ai/llms.txt > Use this file to discover all available pages before exploring further. # Create image (sync) > Generate an image synchronously. Waits for render to complete and returns the image URL. Use ?strict=true to fail on invalid modifications. ## OpenAPI ````yaml /openapi.yaml post /api/v1/images/sync openapi: 3.0.0 info: title: Kynva Public API description: > # Kynva Public API v4.0 The stateless contract API: everything flows through `POST /api/v1/facade/generate` with a `RenderForgeRequestV1` body. ## Entry Points ### Sync preview ``` POST /generate { operation: "preview" } → 200 with rendered outputs ``` ### Async render ``` POST /generate { operation: "render" } → 202 + job → poll GET /render-jobs/{id} or subscribe to webhooks ``` ### Signed image URLs (the OG-image primitive) ``` POST /api/v1/generate/sign → signed GET URLs → 302 to immutable rendered PNGs ``` ## Core Principle Deterministic by construction: the same request, engine version, and seed produce byte-identical output. ## API Versioning Include `X-API-Version: 2026-01-01` in all requests. ## Authentication Include `Authorization: Bearer ` in all requests (signed image GET URLs authenticate by signature instead). ## Idempotency Include `Idempotency-Key: ` for all POST/PATCH mutations. ## Rate Limiting Tiered limits per endpoint category (see documentation). version: 4.0.0 contact: name: Kynva Support url: https://github.com/fredadun/renderforge license: name: MIT url: https://opensource.org/licenses/MIT servers: - url: https://api.kynva.ai description: Production - url: https://renderforge-production-838f.up.railway.app description: Production (direct, until api.kynva.ai DNS lands) - url: http://localhost:3000 description: Development security: - bearerAuth: [] tags: - name: Brands description: Brand management - name: BrandKits description: Brand kit version management - name: Assets description: Asset upload and management - name: Drafts description: Draft creation and workflow - name: Decisions description: Decision records and explainability - name: Render Jobs description: Async render job management - name: Webhooks description: Webhook configuration and DLQ - name: Render Now description: Single-call convenience endpoint - name: Templates (Advanced) description: Template selection and listing - name: Validation (Advanced) description: Stateless validation - name: Compile (Advanced) description: Stateless compilation - name: Licenses (Advanced) description: License checking - name: Spec Render (Advanced) description: Direct spec preview/render - name: Reference description: Reference data (export profiles, API versions) - name: System description: Health checks and system info - name: Images description: Generate images from templates - name: Templates description: Manage reusable templates - name: Health description: Service health and status paths: /api/v1/images/sync: post: tags: - Images summary: Create image (sync) description: >- Generate an image synchronously. Waits for render to complete and returns the image URL. Use ?strict=true to fail on invalid modifications. parameters: - schema: type: boolean default: false in: query name: strict required: false description: Fail on invalid modification properties instead of using fallbacks - schema: type: boolean default: true in: query name: cache required: false description: Use render cache (set to false to force re-render) requestBody: content: application/json: schema: type: object required: - templateId properties: templateId: type: string description: ID of the template to render modifications: type: array description: >- Array of layer modifications (see docs/MODIFICATIONS.md for full list) items: type: object additionalProperties: true properties: name: type: string description: Layer name to modify text: type: string description: New text content src: type: string description: New image URL color: type: string description: New color (hex) hide: type: boolean description: Hide the layer textEffect: type: string description: >- Text effect: clean, shadowed, shadow-soft, shadow-hard, glow, glow-strong, outline, outline-thick, neon, emboss gradientFill: type: object description: >- Gradient text fill: { colors: [...], direction: horizontal|vertical|diagonal } gradient: type: object description: >- Background gradient: { colors: [...], direction: top-bottom|diagonal|radial|... } texture: type: string description: 'Texture overlay: grain, paper, noise, canvas, film' format: type: string enum: - png - jpg - webp default: webp description: Output format scale: type: number minimum: 1 maximum: 3 default: 2 description: Resolution multiplier metadata: type: object description: Custom metadata brandId: type: string description: Brand ID for consistency validation (optional) stylePreset: type: string description: >- Style preset ID to apply (e.g., "retro-80s", "cinematic-teal-orange") variables: type: object description: >- Variables for conditional logic and text interpolation (e.g., { "price": 150, "status": "active" }) additionalProperties: true required: true responses: '200': description: Image generated successfully content: application/json: schema: description: Image generated successfully type: object properties: success: type: boolean data: type: object properties: id: type: string status: type: string enum: - completed imageUrl: type: string description: Public URL of the rendered image width: type: number height: type: number format: type: string renderTime: type: number description: Render time in milliseconds cached: type: boolean description: Whether the result was served from cache stylePreset: type: string description: Style preset that was applied (if any) warnings: type: array description: >- Warnings about unsupported or invalid modification properties items: type: object properties: property: type: string value: {} message: type: string fallback: {} brandValidation: type: object description: Brand validation result (if brandId was provided) properties: valid: type: boolean brandName: type: string violations: type: array summary: type: object components: securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: API Key description: >- Your Kynva API key (kyn_live_xxx or kyn_test_xxx; legacy rf_ keys remain valid) ````