Cognition introduces SWE-2 Flash coding model at 3 times SWE-2 speed and one-fifth cost

Cognition introduced SWE-2 Flash on 4 November 2026, a fast software-engineering model built on Thinking Machines’ sparse mixture-of-experts base model Inkling-Small (276 billion total parameters, 12 billion active per token). Designed for interactive repository navigation, rapid edits and parallel background subagents, SWE-2 Flash streams roughly 200 tokens per second in Cognition’s Terminal-Bench replay, running 3 times faster than flagship SWE-2 at one-fifth its price.

To lift a 12B-active checkpoint to agentic coding reliability, Cognition added a three-stage mid-training curriculum spanning a few trillion tokens before running audited multi-domain reinforcement learning across shell, code-editing and verification environments. Cognition selected mid-training mixtures by tracking token-efficiency loss ratios rather than raw validation perplexity alone, steering capacity toward multi-step tool trajectories.

Cognition’s interactive score charts are rendered in HTML on its blog rather than as downloadable images: mid-training and RL raise Terminal-Bench 4.0 from 0.9% on Inkling-Small to 20.0% on SWE-2 Flash (ahead of 4.0% for Beam 1.0 and 8.0% for Muse Spark Open, versus 27.3% for full SWE-2), FrontierCode 2.0 from 3.2% to 24.0% and ExploitBench from 11.3% to 34.8%. SWE-2 Flash is free for all users in Devin Desktop and Devin CLI through 30 November 2026; citing its 34.8% ExploitBench score, Cognition withheld open weights and is establishing a vetted access programme for external security researchers and partners without publishing standalone token rates.