Run Models

Docs

• Reference: https://replicate.com/docs/llms.txt
• OpenAPI schema: https://api.replicate.com/openapi.json
• MCP server: https://mcp.replicate.com
• Per-model docs: https://replicate.com/{owner}/{model}/llms.txt
• Set Accept: text/markdown when requesting docs pages for Markdown responses.

Workflow

1. Choose the right model - Search with the API or ask the user.
2. Get model metadata - Fetch input and output schema via API.
3. Create prediction - POST to /v1/predictions.
4. Poll for results - GET prediction until status is "succeeded".
5. Return output - Usually URLs to generated content.

Three ways to get output

1. Create a prediction, store its id from the response, and poll until completion.
2. Set a Prefer: wait header when creating a prediction for a blocking synchronous response. Only recommended for very fast models. Max 60 seconds.
3. Set an HTTPS webhook URL when creating a prediction, and Replicate will POST to that URL when the prediction completes.

Guidelines

• Use the POST /v1/predictions endpoint, as it supports both official and community models.
• Every model has its own OpenAPI schema. Always fetch and check model schemas to make sure you're setting valid inputs. Even popular models change their schemas.
• Validate input parameters against schema constraints (minimum, maximum, enum values). Don't generate values that violate them.
• When unsure about a parameter value, use the model's default example or omit the optional parameter.
• Don't set optional inputs unless you have a reason to. Stick to the required inputs and let the model's defaults do the work.
• Use HTTPS URLs for file inputs whenever possible. You can also send base64-encoded files, but they should be avoided.
• Fire off multiple predictions concurrently. Don't wait for one to finish before starting the next.
• Output file URLs expire after 1 hour, so back them up if you need to keep them, using a service like Cloudflare R2.
• Webhooks are a good mechanism for receiving and storing prediction output.

Predictions

• A prediction goes through these states: starting -> processing -> succeeded / failed / canceled.
• Official models use owner/name format. Community models require owner/name:version_id.
• The POST /v1/predictions endpoint handles both.

Webhooks

• Set webhook to an HTTPS URL when creating a prediction. Replicate POSTs the full prediction object when it completes.
• Filter events with webhook_events_filter: start, output, logs, completed.
• Validate webhook signatures using the Webhook-ID, Webhook-Timestamp, and Webhook-Signature headers. Get the signing secret from GET /v1/webhooks/default/secret.

Prediction lifetime

• Set lifetime to auto-cancel predictions that run too long (e.g. 30s, 5m, 1h). Measured from creation time.

Streaming

• Language models that support streaming include a stream URL in the response. Use SSE to receive incremental output.

File handling

• Prefer HTTPS URLs for file inputs. Output URLs from one prediction can be passed directly as file inputs to the next model.
• Output file URLs expire after 1 hour. Download and store them immediately if you need to keep them.

Multi-model workflows

• Chain models by passing output URLs as file inputs to the next model.
• Start all independent predictions in parallel, then collect results.
• Output URLs are valid for 1 hour, which is enough for pipeline steps.