How to Use Fastio API for Batch File Operations

Batch file operations involve uploading, downloading, or processing multiple files programmatically via the Fastio API. This is common in agentic workflows where AI agents need to ingest datasets, media libraries, or document collections into shared workspaces.

Fastio workspaces provide the foundation for batch operations. Each workspace supports file organization, inline previews, semantic search, and AI chat over indexed content. Shares extend this for external collaboration.

Key API capabilities include POST https://api.fast.io/current/upload/batch/ for up to 200 files (4MB each, 100MB total), chunked sessions on POST https://api.fast.io/current/upload/ for larger files, file locks for concurrent access control, and activity polling to track batch progress without constant polling of individual files.

Learn more about workspaces

Start with authentication. Create an API key in Settings > Devices & Agents > API Keys, or with POST https://api.fast.io/current/user/auth/key/. Authenticated calls send Authorization: Bearer {api_key} against https://api.fast.io/current/. Keep the trailing slashes. Workspace IDs are 19-digit numeric strings.

For a batch of small files (up to 200 files, 4MB each, 100MB total), post to the batch route:

POST https://api.fast.io/current/upload/batch/
Authorization: Bearer {api_key}
Content-Type: multipart/form-data

Uploads use multipart/form-data. For larger files, create a session with POST https://api.fast.io/current/upload/ (multipart fields name, size, action=create, instance_id={workspace_id}, folder_id=root; omit the chunk field). Then POST https://api.fast.io/current/upload/{id}/chunk/?order=N&size=N with multipart chunk, POST https://api.fast.io/current/upload/{id}/complete/, and GET https://api.fast.io/current/upload/{id}/details/?wait=60 until the session returns status and new_file_id. A single small file that includes the chunk bytes in the create request returns HTTP 201 with result, id, and new_file_id.

Agent integrations can use the MCP upload tool (actions batch, create-session, chunk, finalize) at https://mcp.fast.io/mcp, or https://mcp.fast.io/mcp/key with a Bearer header.

Implement Batch File Operations with Fastio API

Open a workspace, create an API key, and move file batches with POST /current/upload/batch/ or the MCP upload tool. Built for agent workflows that ingest datasets, media, and document collections.

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Parallelize uploads across multiple connections to maximize throughput. Enable intelligence on workspaces for automatic indexing post-upload. This supports semantic search and RAG chat with Ripley (the built-in RAG agent) over your batch files. When you receive HTTP 429 with error code 1671, back off until the x-ve-limit-expires header, then retry. After the batch lands, invite teammates with POST /current/workspace/{workspace_id}/members/{email_or_user_id}/ and share folders through Send, Receive, or Exchange. Workspace intelligence. For optimal performance, test concurrency limits and adjust based on your observed throughput.

Rate limits return HTTP 429 with error code 1671. Back off until the x-ve-limit-expires header, then retry. Other codes include 1605 Invalid Input, 1609 Not Found, 1650 Auth Invalid, 1680 Access Denied, 1685 Feature Limit, and 1654 Internal Error. For a failed chunk, resend POST /current/upload/{id}/chunk/?order=N&size=N with the same order, then POST /current/upload/{id}/complete/ and GET /current/upload/{id}/details/?wait=60. Confirm workspace membership before you write. Implement structured logging so you can correlate failures across a batch.