prun

# prun (parallel run) ## Overview `prun` fans a task out into independent units that run in parallel on separate-quota or in-session workers, while the Claude session only coordinates. Workers are **Codex** (`codex exec`, a separate abundant account, frontier model) and **Sonnet** subagents (inside the Claude session). **Codex is the prioritized default**: its quota is separate from the Claude plan and its current model (gpt-5.6 tier) is strong on hard reasoning and code, so most units go to Codex. **Sonnet is reserved** for units that need something the Claude session uniquely provides (see the Executors rule). The coordinator decomposes the task, dispatches the units, gathers their results, reviews their diffs, and integrates. It never runs a unit itself. The orchestrator picks the executor per unit; when in doubt, Codex. A Codex unit runs through the separately authenticated Codex/OpenAI account, so the worker run does not draw on the Claude plan at all. A Sonnet unit and the Claude coordinator both consume the current Claude account's quota; the exact split across models and weekly buckets depends on the plan and on active promotions and shifts over time, so check Settings > Usage before relying on any model-specific split. Codex is the default because its worker run is outside the Claude plan; keep Sonnet units targeted because they draw Claude-side quota. ## Relationship to the native Workflow tool The native Workflow tool fans a task out across **Claude** subagent...