Flint: Open-Weight MoE Model for Coding Agents
Flint is Recursive's mixture-of-experts language model for coding agents. It is designed to investigate codebases, fix bugs, implement features, and write tests, and it supports reasoning and multi-turn tool use. Flint was trained from scratch through pretraining, mid-training, supervised fine-tuning, and reinforcement learning.
The model is published at RecursiveSI/flint.
Key Features
- Built for coding agents - Trained on text, code, instruction following, and agentic tasks, aimed at agents that work through a codebase over many steps.
- Small active footprint - About 2.5B of its 39.8B parameters are active per token, so decoding is fast for a model of its total size.
- Reasoning - Thinks before answering; the reasoning is returned separately from the final answer.
- Tool calling - OpenAI-compatible tool calls for multi-turn agent workflows.
- Long context - A 262,144-token context window shared between prompt and output.
Architecture
Flint is a decoder-only mixture-of-experts transformer in which each token is routed to a small set of experts plus an always-active shared expert. Most layers use local sliding-window attention, and only a minority attend to the full context, so long contexts stay cheap in memory.
Benchmarks
In Recursive's release evaluations Flint scores 54.9% on Terminal-Bench 2.1, 89.7% on SWE-bench Pro v2, and 74.2% on SWE-bench Verified. Agentic scores are the average pass@1 over at least five attempts, with Terminal-Bench run through Terminus 2 and SWE-bench through mini-swe-agent.
Use Cases
- Coding agents that read a repository, then edit and test code
- Bug fixing and feature implementation
- Writing tests for existing code
- Tool-using assistants built on OpenAI-compatible function calling
Sampling
The publisher recommends a temperature of 1.0 with top-p 0.95 and top-k 20, and an output budget of at least 32,768 tokens on hard problems, since reasoning counts toward the output limit. Keep returned reasoning content in the conversation history across turns.
