> ## Documentation Index > Fetch the complete documentation index at: https://docs.varg.ai/llms.txt > Use this file to discover all available pages before exploring further. # Apply presets to a request body > Merges one or more presets into a request body you intend to send to a generation endpoint and returns the finished payload. The tool is inferred from `payload.model`. Presets that cannot be applied (unknown, no mapping for the model's tool, or dropped by the model's schema) are reported in `rejected` instead of failing the call. Returns `200` when at least one preset applied and `422` when none did; the `422` body then still has the `payload`/`applied`/`rejected` shape. A `422` with an `error` envelope means the model in `payload.model` is unknown. Auth is optional. ## OpenAPI ````yaml /openapi.yaml post /presets/apply openapi: 3.1.0 info: title: varg API version: 2.0.0 description: | Unified REST API for AI media generation at `api.varg.ai/v2`. One API key, ~80 models across 8 providers, async jobs, stable output URLs on `s3.varg.ai`, files with lineage, and transparent credit billing (1 credit = 1 cent = $0.01). **The async job pattern:** every generation request returns `202 Accepted` with a job object (`status: queued`). Poll `GET /jobs/{id}` until the job reaches a terminal status (`completed`, `failed`, or `cancelled`), then read `output.outputs[0].url`. Alternatively, set `options.webhook_url` in the request to receive an HMAC-signed callback when the job finishes. servers: - url: https://api.varg.ai/v2 security: - bearerAuth: [] tags: - name: Generation description: >- Create generation jobs (image, video, speech, music, transcription, ffmpeg, render, pipeline) - name: Tools description: Discover tools, their schemas, and call any tool generically - name: Jobs description: Poll and manage job lifecycle - name: Files description: Upload, import, probe, and manage files - name: Folders description: Group files into folders and file generated output automatically - name: Lineage description: Resolve which job produced a file - name: Presets description: Browse and apply reusable parameter values — voices, styles - name: Templates description: Browse, publish, use and render community templates - name: Pricing description: Estimate costs and browse the price catalog - name: Billing description: Balance, usage, and transaction history - name: Analytics description: >- Spend, runs and files over time — summaries, time series, breakdowns, activity - name: Account description: Identity and API key management paths: /presets/apply: post: tags: - Presets summary: Apply presets to a request body description: > Merges one or more presets into a request body you intend to send to a generation endpoint and returns the finished payload. The tool is inferred from `payload.model`. Presets that cannot be applied (unknown, no mapping for the model's tool, or dropped by the model's schema) are reported in `rejected` instead of failing the call. Returns `200` when at least one preset applied and `422` when none did; the `422` body then still has the `payload`/`applied`/`rejected` shape. A `422` with an `error` envelope means the model in `payload.model` is unknown. Auth is optional. operationId: applyPresets requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/PresetApplyRequest' example: payload: model: eleven_multilingual_v2 text: Hello world presets: - preset_5f4dcc3b5aa7 responses: '200': description: At least one preset was applied content: application/json: schema: $ref: '#/components/schemas/PresetApplyResponse' examples: applied: value: payload: model: eleven_multilingual_v2 text: Hello world voice: preset_5f4dcc3b5aa7 applied: - preset_5f4dcc3b5aa7 rejected: [] '400': description: >- Body is not a JSON object, `payload` is missing or not an object, `payload.model` is missing, or `presets` is empty content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '422': description: | Nothing was applied. The body is a `PresetApplyResponse` (with a non-empty `rejected` list), or an `ErrorResponse` with code `unknown_model` when `payload.model` is not in the catalogue. content: application/json: schema: oneOf: - $ref: '#/components/schemas/PresetApplyResponse' - $ref: '#/components/schemas/ErrorResponse' security: - {} - bearerAuth: [] components: schemas: PresetApplyRequest: type: object required: - payload - presets properties: payload: type: object additionalProperties: true description: >- The request body you intend to send to a generation endpoint. `model` is required; the tool is inferred from it. presets: type: array minItems: 1 items: type: string description: >- Preset ids to merge, applied in order. Non-string entries are ignored. PresetApplyResponse: type: object required: - payload - applied - rejected properties: payload: type: object additionalProperties: true description: The merged request body, ready to send to the generation endpoint. applied: type: array items: type: string description: Ids of the presets that were merged. rejected: type: array items: $ref: '#/components/schemas/PresetRejection' ErrorResponse: type: object properties: error: type: object properties: code: type: string example: model_not_found message: type: string example: 'Unknown model: flux-shnell' details: {} PresetRejection: type: object required: - id - reason - message properties: id: type: string reason: type: string enum: - unknown_preset - incompatible - catalogue_error - not_accepted_by_model description: > `unknown_preset`: id not in the catalogue. `incompatible`: no mapping for the model's tool. `catalogue_error`: the preset's mapping data is broken. `not_accepted_by_model`: the model's schema would silently drop the value. message: type: string available_tools: type: array items: type: string description: Present for `incompatible`; the tools this preset can be applied to. securitySchemes: bearerAuth: type: http scheme: bearer description: | varg API key (`varg_...`). Get one at [app.varg.ai](https://app.varg.ai) or run `bunx vargai login`. App sessions may alternatively send a Supabase JWT. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.