create_prediction
Generate high-quality images from text prompts using the Flux Schnell model. Customize aspect ratio, output format, and quality for tailored results.
Instructions
Generate an prediction from a text prompt using Flux Schnell model
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| aspect_ratio | No | Aspect ratio for the generated image | 1:1 |
| disable_safety_checker | No | Disable safety checker for generated images. | |
| go_fast | No | Run faster predictions with model optimized for speed (currently fp8 quantized); disable to run in original bf16 | |
| megapixels | No | Approximate number of megapixels for generated image | 1 |
| num_inference_steps | No | Number of denoising steps. 4 is recommended, and lower number of steps produce lower quality outputs, faster. | |
| num_outputs | No | Number of outputs to generate | |
| output_format | No | Format of the output images | webp |
| output_quality | No | Quality when saving the output images, from 0 to 100. 100 is best quality, 0 is lowest quality. Not relevant for .png outputs | |
| prompt | Yes | Prompt for generated image | |
| seed | No | Random seed. Set for reproducible generation |
Implementation Reference
- src/tools/createPrediction.ts:7-30 (handler)The handler function that executes the create_prediction tool: creates a prediction via Replicate API with the given input, polls for completion, and returns the result as text JSON.
export const registerCreatePredictionTool = async ( input: CreatePredictionParams ): Promise<CallToolResult> => { try { const prediction = await replicate.predictions.create({ model: CONFIG.imageModelId, input, }); await replicate.predictions.get(prediction.id); const completed = await pollForCompletion(prediction.id); return { content: [ { type: "text", text: JSON.stringify(completed || "Processing timed out", null, 2), }, ], }; } catch (error) { handleError(error); } }; - src/types/index.ts:3-69 (schema)Input schema using Zod for validating parameters of the create_prediction tool, including prompt, seed, aspect ratio, etc.
export const createPredictionSchema = { prompt: z.string().min(1).describe("Prompt for generated image"), seed: z .number() .int() .optional() .describe("Random seed. Set for reproducible generation"), go_fast: z .boolean() .default(true) .describe( "Run faster predictions with model optimized for speed (currently fp8 quantized); disable to run in original bf16" ), megapixels: z .enum(["1", "0.25"]) .default("1") .describe("Approximate number of megapixels for generated image"), num_outputs: z .number() .int() .min(1) .max(4) .default(1) .describe("Number of outputs to generate"), aspect_ratio: z .enum([ "1:1", "16:9", "21:9", "3:2", "2:3", "4:5", "5:4", "3:4", "4:3", "9:16", "9:21", ]) .default("1:1") .describe("Aspect ratio for the generated image"), output_format: z .enum(["webp", "jpg", "png"]) .default("webp") .describe("Format of the output images"), output_quality: z .number() .int() .min(0) .max(100) .default(80) .describe( "Quality when saving the output images, from 0 to 100. 100 is best quality, 0 is lowest quality. Not relevant for .png outputs" ), num_inference_steps: z .number() .int() .min(1) .max(4) .default(4) .describe( "Number of denoising steps. 4 is recommended, and lower number of steps produce lower quality outputs, faster." ), disable_safety_checker: z .boolean() .default(false) .describe("Disable safety checker for generated images."), }; - src/tools/index.ts:51-56 (registration)Registration of the 'create_prediction' tool on the MCP server, providing name, description, schema, and handler function.
server.tool( "create_prediction", "Generate an prediction from a text prompt using Flux Schnell model", createPredictionSchema, registerCreatePredictionTool );