prun¶
Fan out independent task units to Codex and Sonnet workers while the Opus session coordinates. Workers spend their separate quotas in throwaway clones, and Opus plus the user remain the final integration gate.
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 subagents under a deterministic script, with structured output, judge panels, and resume. A Workflow run counts against the Anthropic plan's usage and rate limits, and its agents use the session model unless the script routes a stage to a different Claude model.
prun has a different quota shape. A Codex unit is dispatched by a shell call to codex exec,
so the worker run uses the separate Codex/OpenAI account. A Sonnet unit and the coordinating
session both draw the current Claude account's quota, so reserve Sonnet for units that need the
Claude session's own tools. The coordinating session also spends a small Anthropic amount while it
decomposes, dispatches, reads results, and integrates.
The two relate in two ways, both with the current session as the orchestrator:
- Substitute (quota). When the Anthropic pool is too constrained to run a Workflow, use prun with Codex-only units, or keep any Sonnet units small and targeted. This shifts the heavy fan-out to Codex while leaving only the coordinator and any chosen Sonnet work in the Anthropic pool.
- Complement (diversity). When a Workflow is affordable and you want cross-vendor perspectives, run a Claude panel through the Workflow and a Codex panel through prun. Use the same structured contract and the same question on both sides, then cross-check. Agreement across vendors is usually a stronger signal than agreement inside one model family, because shared model lineage and tools can share blind spots. Invoke them together in one natural-language request; no special mode is needed. Reserve this for high-stakes work (a review, an audit, a hard design call), since it spends both pools and the coordinator must merge two result sets.
When to use¶
Use prun when the task splits into independent units that can run at once (different
modules, separate research questions, parallel analyses). Units may be heterogeneous, and there
can be many of them: a dozen or twenty in parallel is normal when the task warrants it.
Do not use prun when the task is one sequential unit, or units depend on each other's output,
or a unit's result cannot be checked without redoing it.
Executors¶
| Executor | Quota | Notes |
|---|---|---|
Codex (codex exec) |
Separately authenticated Codex/OpenAI account; abundant | Prioritized default. Frontier model (gpt-5.6 tier), strong on hard reasoning and code, and the worker run spends no Claude-plan quota. Run many in parallel. |
| Sonnet subagent | Current Claude account; check Settings > Usage for the applicable limits or credits | Reserved, not a default. Runs in the Claude session, so it alone can reach session-internal tools (MCP / email / Artifacts) that Codex cannot. |
| Claude session (this session) | Current Claude account; check Settings > Usage for the applicable limits or credits | Coordinator and integrator only, on whatever model is selected. Never a unit. |
Rule: units never run on the coordinator (the Claude session itself). The orchestrator picks the executor per unit, with a strong default toward Codex:
- Codex is the default for almost every unit (code, research, analysis, web fetch). Its quota is separate and abundant and its frontier model (gpt-5.6 tier) is capability-competitive with the top Claude models, so there is rarely a reason to prefer another worker. Start here.
- Sonnet is the reserved exception, chosen only when a unit needs a tool the Claude session has but
the isolated Codex worker does not. Codex is an external process, so route to Sonnet when a unit
needs a session-internal MCP / email connector (Gmail, Calendar, Drive, Slack), the Artifact tool,
or a cross-vendor web-search verification where you want a Claude-side
WebSearchresult to cross-check the Codex one. A normal Sonnet subagent inherits the session's available tools but starts with fresh, isolated context (it does not see the conversation history), so put any needed state in its unit prompt; if a task truly needs the full live conversation, keep it in the coordinator (an explicit fork inherits that context but also the coordinator's model, so it is not a Sonnet worker). The orchestrator decides per unit; when in doubt, use Codex. Sonnet draws Claude-side quota, so keep these units targeted. - The Claude session stays the coordinator, never a unit. A single small session-tool task the coordinator can do inline; reach for Sonnet when you need to run many such units in parallel.
Concurrency¶
The orchestrator decides the unit count autonomously. Partition the task by dependency structure (split only along genuinely independent boundaries) and balanced workload (roughly equal-sized units, each worth a full worker run). High autonomy is the intent: do not target a fixed number, and do not cap artificially. A dozen-plus in parallel is fine when the task genuinely decomposes that way.
Two soft bounds, not hard rules: local CPU/RAM (heavy Codex workers contend past roughly a handful at once, and the excess just queues) and Codex quota headroom. The usual real ceiling is integration bandwidth, since the orchestrator must read and reconcile every result, so prefer fewer well-scoped units over many tiny ones. Over-splitting into trivial units wastes worker startup and tends to produce thin results.
What a unit may do, and the one rule¶
A unit may read or write code, run commands, and fetch the web, with full access. The single
hard rule: a worker never commits, pushes, or runs destructive git (commit, push,
branch/tag mutation, reset --hard, clean). Everything else is allowed. The final gate is
the Claude session integrating the results and the user deciding; workers never touch the real repo history.
This is enforced structurally, not by trust:
- Read-only / research units run from a per-unit scratch cwd, so accidental writes stay out of
the repo.
dispatch-taskdoes this by default. - Code-writing units run inside a throwaway local clone of the repo with its remote removed:
The worker edits freely in the clone. An accidental
git clone --local -c core.longpaths=true <repo> <clone-dir> # longpaths: Windows MAX_PATH safety git -C <clone-dir> remote remove origingit pushhas no remote to reach (GitHub / Overleaf stay untouched); an accidentalgit commitonly lands in the throwaway clone. The coordinator readsgit -C <clone-dir> diff, integrates the wanted changes into the real tree, and the user approves the actual commit. That is the only gate.
No credential scrubbing or sandbox wall: the user writes the prompts, the clone has no path to the real remotes, and the Claude session plus the user are the integration gate. That is the whole safety model.
Flow¶
- Gate: confirm the task splits into independent, checkable units. Else use a single worker.
- Decompose: write one prompt per unit. State the task; for a code-writing unit, that the working dir is a throwaway clone to edit freely but not commit or push; that the unit writes a result summary to its result file (a fresh path, in one write).
- Assign: default the unit to Codex; pick Sonnet only for the reserved cases (session-internal MCP / email / Artifacts, or cross-vendor web verification). Also pick read-only (scratch) or code-writing (clone) mode. For a web-heavy unit, "Web access" below covers which executor fits.
- Dispatch in parallel:
- Codex unit: run
scripts/dispatch-task.{sh,ps1}in the background (Bash tool,run_in_background=true). For a code-writing unit, pass the clone dir viaPRUN_SCRATCH_CWD. - Sonnet unit: spawn a background Agent subagent with
model: sonnet. It inherits the session's available tools, including MCP and connector tools; if you set atoolsallowlist, include every connector, Artifact, file, shell, and web tool the unit needs. The subagent starts with fresh context, so put any needed state in its prompt. For code-writing it works in a clone too, under Claude'sguard.py, which already gates commit/push. - Monitor (do not go idle): launch
scripts/monitor.{sh,ps1} <state-dir> ...in the background (run_in_background=true) and wait on its completion. It wakes you on the first actionable event: all done, any unit stalled (tail no-growth forPRUN_STALL_THRESHOLD, default 10 min), or any unit failed (FALLBACKresult or dead dispatch), printing a per-unit digest. On a stall, surface it to the user with a likely cause (capacity or concurrency pressure; suggest lowering the worker count or re-dispatching) rather than waiting silently; act, then re-launch the monitor on the still-running units until all are done.monitoronly observes; the unit's owndispatch-taskreaps a worker idle pastPRUN_STALL_THRESHOLDat the same threshold, so a persistent stall surfaces as aFALLBACKto re-dispatch rather than a leaked zombie. (gather.{sh,ps1}remains for the plain wait-for-all case.) - Reconcile, then integrate: before integrating, reconcile the ledger: every dispatched unit
must have a non-empty result. If any is missing or empty, do not integrate the partial set;
recover the worker's output from its
<state-dir>/tail(dispatch-task also salvages the tail into the result file automatically under aFALLBACKheader), then re-dispatch or flag the user if it is unusable. Then the coordinator reads each result plus each clone'sgit diff, merges the wanted changes into the real tree, runs verification, and asks the user before any commit.
Resolve scripts via this order, first hit wins: skills/prun/scripts/, then
.claude/skills/prun/scripts/, then .agent-config/repo/skills/prun/scripts/.
dispatch-task usage (Codex)¶
- Emits exactly one stdout line
STATE-DIR <abs-path>; codex stdout+stderr land in<state-dir>/tail. - If the worker exits without writing a non-empty result file, dispatch-task salvages its captured
<state-dir>/tailinto the result file under aFALLBACKheader, so a failed result-write never makes the unit silently vanish at gather. Treat aFALLBACKresult as "review or re-dispatch." - Self-heals a hung worker: if the tail stops growing for
PRUN_STALL_THRESHOLDseconds (default600; the same idle signalmonitorreports) or the run exceedsCODEX_DISPATCH_TIMEOUTseconds (default0= hard cap off, so the idle signal stays primary and an actively streaming long run is not killed), dispatch-task kills the worker's whole process tree, exits124, and writes theFALLBACKabove namingidle-stallorhard-timeout. A non-empty result the worker already wrote is preserved, never clobbered. On Windows the watch+kill runs in the siblingreap-watch.ps1(an AMSI-safe split of launch from watch+kill; the.shdoes it inline). - Runs codex from a per-unit working dir: a scratch dir by default (read-only units), or the path in
PRUN_SCRATCH_CWD(point this at a throwaway clone for code-writing units). - Env:
CODEX_DISPATCH_SANDBOX(defaultdanger-full-access),CODEX_DISPATCH_REASONING(defaultxhigh),CODEX_DISPATCH_ISOLATE_MCP=offto drop MCP isolation,PRUN_SCRATCH_CWDto set the cwd,PRUN_STALL_THRESHOLD(default600) for the idle-reap threshold,CODEX_DISPATCH_TIMEOUT(default0= disabled) for an optional hard wall-clock cap.
Sonnet usage¶
Sonnet is the reserved executor (see Executors), for units needing session-internal tools (MCP /
email connectors, the Artifact tool) or a cross-vendor web verification. Spawn an Agent-tool subagent
with model: sonnet. It inherits the session's available tools but starts with fresh context (it
does not see the conversation), so put any needed state in the unit prompt. Give it the same return
contract and result-file path. For a code-writing unit, point it at a clone dir; commit and push are
also gated by guard.py on the Claude side.
gather usage¶
- Prints
GATHER-START count=N timeout=Ss, thenDONE <abs-path>per file as it lands; exits 0 when all land, exits 2 withTIMEOUT remaining=<k>. - A file is "landed" when it exists, is non-empty, and has been quiet for the stable window (default 10s); no startup-snapshot race.
- Use a fresh result path per unit per run (delete any stale file before dispatch). Have each unit write its result in one operation.
monitor usage¶
- Takes the
STATE-DIRpaths from each dispatch (not result files); reads each unit'stail(growth),result-file(done/fail), anddispatch-pid(liveness). - Prints
MONITOR-START units=N stall-threshold=Ts timeout=Ss, then on the first actionable eventMONITOR-EVENT <all-done|stall|fail|timeout>and oneUNIT <name> <status>line per unit (done/failed(fallback)/failed(dispatch-dead)/stalled(Ns)/growing). - Exit:
0all done,3attention needed (a stall or fail),2hard timeout. - Env:
PRUN_STALL_THRESHOLD(default 600, ten minutes; raise it for long code-writing units),PRUN_MONITOR_POLL(default 15),PRUN_MONITOR_TIMEOUT(default 3600),PRUN_MONITOR_STABLE_WINDOW(default 10). - Run it in the background; after handling a stall or fail, re-launch on the still-running units so a resolved unit is not re-flagged.
Return contract (every unit writes this)¶
# <unit-id> result
Conclusion: <one line>
Files: <files created/modified in the clone, or "none (read-only)">
Open items: <blockers or follow-ups, or "none">
Verification: <what was run/checked/searched, or "none">
<body: the findings, survey, analysis, or change summary>
Ledger¶
Keep a simple run ledger (a file in a scratch area) recording each unit: id, executor, mode, prompt file, state-dir / clone-dir, result file, status (dispatched / done / failed), start/end. Use it to report progress and to relaunch only units whose result is missing or fails validation.
Web access¶
Both executors reach the web by different paths, each with its own strengths, so assign per unit.
Codex runs on the user's local machine, so its requests leave from the user's local network
rather than the cloud fetcher's egress IP, often a residential IP. That can reach some pages a cloud
fetcher gets 403 on, though a hardened site can still block on bot score, fingerprint, or rate. It
also surfaces pages a cloud fetch would miss. Web access comes from --sandbox danger-full-access
(built-in browser path, confirmed under MCP isolation). Codex quota is abundant, so the extra unit is
cheap.
Sonnet units get web from an agentType granting built-in WebSearch and WebFetch. Claude's
WebSearch is strong at broad discovery (finding the right page when the URL is unknown), but
discovery alone is not a session-internal capability, so treat Sonnet here as a reserved path for an
explicitly wanted Claude-side cross-check or for recovery after Codex discovery falls short, not as
the default for discovery.
Routing heuristic (apply the Executors rule; when in doubt, Codex):
- Fetch or discover on one path: use a Codex unit first, whether or not the URL is known. Its
local-network path also reaches some pages a cloud fetch gets
403on. - Codex discovery fell short, or acceptance needs a Claude-side result: add a targeted Sonnet
unit and its
WebSearch. - A high-stakes fact that might be stale or blocked: run Codex first, then add a Sonnet cross-check when the value of a second vendor's view justifies the Claude-side quota.
A Codex web-fetch unit can use curl. Report the HTTP status per URL so a cloud-vs-local block shows
up in the result. In Windows PowerShell, name the binary curl.exe, since a bare curl can resolve
to the Invoke-WebRequest alias instead: