What they did
Mao and Mirhoseini introduce DeLM, a decentralized multi-agent system for large language model reasoning. Instead of a central orchestrator assigning subtasks and merging results, DeLM uses a shared verified context and a task queue. Agents asynchronously claim subtasks, read the accumulated context, perform local reasoning, and write back compact verified updates. The authors evaluated DeLM on two benchmarks: SWE-bench Verified (software-engineering test-time scaling) and LongBench-v2 Multi-Doc QA (long-context reasoning). They compared against several baselines, including centralized multi-agent systems and single-agent approaches.
Key findings
- On SWE-bench Verified, DeLM achieved the best performance across Avg.@1, Pass@2, and Pass@4, with gains of up to 10.5 percentage points over the strongest baseline.
- DeLM reduced cost per task by roughly 50% compared to baselines on SWE-bench Verified.
- On LongBench-v2 Multi-Doc QA, DeLM achieved the highest average accuracy across four frontier model families, improving over the strongest baseline by up to 5.7 percentage points.
Why it matters
Decentralized coordination through a shared context eliminates the communication and integration bottleneck of centralized multi-agent systems. This work demonstrates that scaling test-time reasoning with multiple agents can be both more efficient and more effective without a central controller, potentially enabling larger and more complex multi-agent deployments.
Caveats
The paper evaluates DeLM on specific benchmarks (SWE-bench and LongBench), so generality across other domains remains unverified. The shared context relies on a verification mechanism to ensure correctness; the overhead and robustness of this mechanism are not fully characterized. The cost savings assume a particular pricing model and may vary with different LLM providers.