request_upload_url
Generate a presigned upload URL for large artifacts (500 MB to 5 GB) to upload directly to R2 storage, avoiding size limits of store_artifact.
Instructions
Reserve a presigned R2 PUT URL for a file too large to send through store_artifact (over 500 MB up to 5 GB). Returns an upload_url, headers to include in the PUT, and an artifact_id in pending state. The agent (or its environment) PUTs the bytes directly to R2, then calls complete_upload. Pro plan only. Most agents should use store_artifact and let the MCP server pick the path automatically.
Not retry-safe: this endpoint does not support idempotency keys, so on an HTTP 5xx or network error the reservation may or may not have been created. Do NOT blindly retry — the error guidance tells you to first call list_artifacts with the same session_id/agent_id to detect any pending artifact, so you don't create a duplicate.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| filename | Yes | ||
| content_type | Yes | ||
| size_bytes | Yes | ||
| session_id | No | ||
| agent_id | No | ||
| metadata | No | ||
| ttl | No |