Arcee open-sources NAC agent harness; 489 tool calls, 67 passing tests on DeepSeek V4.1 Flash

MaziyarPanahi · x · 2026-09-12

Arcee AI open-sourced NAC (arcee-ai/nac), an agent harness for long-running ambitious tasks. It uses a thread-and-episode architecture: a central orchestrator plans and decomposes work but cannot execute commands or edit files — it only launches threads that return structured episode summaries, keeping long tasks aligned with original intent.

The author stress-tested DeepSeek V4.1 Flash's tool calling with it: 489 tool calls over 56 minutes, 67 passing tests, and a working explorer for real LIGO data. The repo has 238 stars, includes quickstart scripts, and cites inspiration from slate, nanocode, and pi.

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