PERSEUS: Non-Blocking Parallel Exploration with a Speculative Swarm

Tool-using agents face a breadth–coordination trade-off: a single agent follows a coherent task trajectory but discovers evidence mainly along its chosen call path, while multi-agent exploration broadens discovery through additional coordination. PERSEUS couples one authoritative main agent, the Actor, with a non-blocking speculative swarm. Single-round Speculators use constrained variants of native tools to explore complementary information needs in independent work copies, while the Actor retains task decisions and state changes. Persistent Futures carry unfinished acquisitions across Actor requests. A source-aware ledger admits completed observations with their provenance, allowing the Actor to continue while pending exploration proceeds asynchronously. Cooperation occurs through evidence: a Speculator's inspection can inform a different later action. On selected tasks from four benchmarks, PERSEUS achieves the highest overall end-to-end task success among 13 baselines, improving success from ReAct's 56.3% to 67.8% and Execution Speed from 2.43 to 3.20 ($10^{-3}{\mathrm{s}}^{-1}$). Temporal analysis, ablations, and scaling relate these outcomes to evidence flow, exploration structure, and persistence. Harness comparisons show fewer Actor turns with maintained or improved quality relative to single-agent controls. The results support broad exploration through asynchronous cooperation under one authority.