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Fleet RLM is a Python agent runtime for work that needs reasoning, Python, and files. You ask a question in the terminal, watch the work stream in, and return to the saved Session later. The current implementation is also called Fleet RLM Lite. Fleet RLM combines four pieces:
  • DSPy runs each Turn through a direct, flex, or rlm route.
  • Daytona sandboxes run every line of model-authored Python, outside the Fleet process.
  • PostgreSQL stores durable Session state: Turn history, file content, memories, and Session selections.
  • MLflow records traces and runs evaluation. Fleet uses a local MLflow server by default.
A FastAPI server streams progress over Server-Sent Events (SSE). The terminal client and your own clients use the same HTTP API. Fleet RLM 0.8.0 requires Python 3.11 to 3.13 and supports DSPy 3.4.1 or later, below 3.5.

What you can do

  • See the work as it happens. The terminal shows routing, generated Python, tool activity, child sandboxes, and the final answer in one timeline.
  • Continue a Session. History, workspace files, reviewed memory, and model and mode selections survive a restart. Python variables in the sandbox are not durable.
  • Work with large files. Large inputs stay in workspace files. The model receives paths, metadata, and bounded previews, then explores the data through Python.
  • Delegate independent work. spawn_agent runs a subtask in a fresh child sandbox. spawn_agents runs independent subtasks concurrently within shared limits.
  • Evaluate and optimize. Label traces, score Turns, and compile GEPA candidates with fleet eval and fleet optimize.
  • Drive it from your own client. The same server runs without the terminal and exposes an HTTP and SSE API.

How the pieces fit

The server runs each Turn on a worker thread, executes model-authored Python in Daytona, and streams progress to the client. Fleet commits the Turn to Session history before it reports the Turn as persisted.

Next steps

Quickstart

Install Fleet RLM and run your first live Session.

How Fleet RLM works

Follow a Turn from request to committed result.

Use the terminal

Slash commands for files, Sessions, models, Skills, and traces.

HTTP API

Sessions, Turns, workspace files, and the SSE stream.
Last modified on October 20, 2026