iterate · diff
git:20260410.d221136 to git:20260425.fccfd65
172 added, 58 removed. Audit A to A.
---
name: iterate
- description: "Autonomous improvement loop - modify, measure, keep or discard, repeat. Inspired by Karpathy's autoresearch. Triggers on: iterate, improve autonomously, run overnight, keep improving, autoresearch, improvement loop, iterate until done, autonomous iteration."
+ description: "Autonomous improvement loop - modify, measure, keep or discard, repeat. Inspired by Karpathy's autoresearch. Triggers on: iterate, improve autonomously, run overnight, keep improving, autoresearch, improvement loop, iterate until done, autonomous iteration, batch experiments."
license: MIT
allowed-tools: "Read Write Edit Glob Grep Bash Agent TaskCreate TaskUpdate TaskList"
metadata:
author: claude-mods
---
# Iterate - Autonomous Improvement Loop
- Inspired by [Karpathy's autoresearch](https://github.com/karpathy/autoresearch): constrain scope, clarify success with one mechanical metric, loop autonomously. The agent modifies code, measures the result, keeps improvements, discards regressions, and repeats - indefinitely or for N iterations.
+ Inspired by [Karpathy's autoresearch](https://github.com/karpathy/autoresearch): constrain scope, clarify success with one mechanical metric, loop autonomously. The agent modifies code, measures the result, keeps improvements, discards regressions, and repeats - until any stop condition fires or the user interrupts.
The power is in the constraint. One metric. One scope. One loop. Git as memory.
## Preflight
Before the loop starts, do the work that makes the loop effective. Don't skip steps - this discipline is what separates a productive overnight run from a flailing one.
### 1. Collect Config
- Five inputs. If provided inline, extract and proceed. If any are missing, ask once using `AskUserQuestion` with all missing fields batched together.
+ If provided inline, extract and proceed. If required fields are missing, ask once using `AskUserQuestion` with all missing fields batched together.
| Field | Required | What it is | Example |
|-------|----------|------------|---------|
| **Goal** | Yes | What you're improving, in plain language | "Increase test coverage to 90%" |
| **Scope** | Yes | File globs the agent may modify | `src/**/*.ts` |
| **Verify** | Yes | Shell command that outputs the metric (a number) | `npm test -- --coverage \| grep "All files"` |
| **Direction** | Yes | Is higher or lower better? | `higher` / `lower` |
| **Guard** | No | Command that must always pass (prevents regressions) | `npm run typecheck` |
+ | **Batch** | No | Changes per iteration. >1 enables bisect-on-regression. Default `1`. | `3` |
+ | **Iterations** | No | Hard cap on iteration count. | `30` |
+ | **Until** | No | Stop when metric crosses this target value. | `90` |
+ | **Stagnation** | No | Stop after N consecutive iterations with no improvement. | `15` |
+ | **Branch** | No | Branch isolation. `current` (default), `auto` (slug from goal), or explicit name. | `auto` |
- **Bounded mode:** If the user includes `Iterations: N`, run exactly N iterations then stop with a summary. Otherwise, loop forever until interrupted.
+ **Stop conditions are OR'd**: any combination of `Iterations`, `Until`, `Stagnation` may be set. The loop stops when any one is satisfied. If none are set, the loop is unbounded - it runs until interrupted.
### 2. Plan
Read all in-scope files. Understand the codebase before touching anything.
- What's the current state? What's already been tried?
- What are the likely improvement vectors? Rank them.
- What are the risks? What could break?
- Form a rough strategy for the first 5-10 iterations.
### 3. Permissions
Check that `allowed-tools` cover what the loop needs. The verify and guard commands must run without permission prompts - a blocked tool at 3am kills the whole run.
- Dry-run the verify command. If it gets blocked, note which `Bash(command:*)` pattern is needed.
- Dry-run the guard command (if set). Same check.
- If permissions are missing, suggest specific wildcard additions for `.claude/settings.local.json` and ask the user to approve before starting. Reference `/setperms` for a full setup.
- ### 4. Tasks
+ ### 4. Branch Setup
+ The `Branch` field controls where iteration commits land.
+
+ | Value | Behavior |
+ |-------|----------|
+ | `current` (default) | Stay on the current branch. Commits land directly. |
+ | `auto` | Create `iterate/<slug-from-goal>` from current HEAD and switch to it. |
+ | `<explicit-name>` | Create branch with that exact name and switch to it. |
+
+ **Slug derivation** (for `auto`): lowercase the Goal, replace non-alphanumeric runs with `-`, trim leading/trailing dashes, truncate to 40 chars. "Increase test coverage to 90%" → `iterate/increase-test-coverage-to-90`.
+
+ **Collision**: if the branch already exists, suffix `-2`, `-3`, etc.
+
+ **Confirm before switching**: print the chosen branch name and source branch. Do not silently create a branch the user didn't ask for.
+
+ **Cleanup**: never auto-delete the branch. The user decides whether to merge, open a PR, or `git branch -D` it. The skill's job ends at "branch exists with results."
+
+ ### 5. Tasks
+
Create a TaskList to track progress across iterations. This provides structure the user can check without reading the full results log.
```
TaskCreate: "Establish baseline" (status: in_progress)
TaskCreate: "Iteration loop - [goal]" (status: pending)
TaskCreate: "Final summary and cleanup" (status: pending)
```
Update task status as the loop progresses. Mark the iteration task as `in_progress` when the loop starts, `completed` when it ends.
- ### 5. Tests and Verification
+ ### 6. Tests and Verification
Before the first iteration, make sure verification actually works:
- Run the verify command on the current state. If it fails or produces no parseable number, fix this first.
- Run the guard command (if set). If it fails on the current state, the codebase has pre-existing issues - flag to the user.
- If tests don't exist yet for the scope, consider writing them as iteration 0. Good tests make the loop more effective.
- ### 6. Baseline
+ ### 7. Baseline
Record the starting point:
1. Run verify command, extract the metric - this is iteration 0
2. Create `results.tsv` with the header and baseline row
- 3. Update the baseline task to `completed`
- 4. Confirm setup to the user, then begin the loop
+ 3. Tag the baseline: `git tag iterate/best` (will float forward as the metric improves)
+ 4. Update the baseline task to `completed`
+ 5. Confirm setup to the user, then begin the loop
```
- Goal: Increase test coverage to 90%
- Scope: src/**/*.ts
- Verify: npm test -- --coverage | grep "All files"
- Direction: higher
- Guard: npm run typecheck
- Baseline: 72.3%
- Mode: unbounded
- Tasks: 3 created
- Permissions: verified (all commands pre-approved)
+ Goal: Increase test coverage to 90%
+ Scope: src/**/*.ts
+ Verify: npm test -- --coverage | grep "All files"
+ Direction: higher
+ Guard: npm run typecheck
+ Branch: iterate/increase-test-coverage-to-90 (created from main)
+ Batch: 3
+ Stop: Iterations 50 OR Until ≥ 90.0 OR Stagnation 15
+ Baseline: 72.3
+ Permissions: verified
Starting iteration loop.
```
## The Loop
```
- LOOP (forever, or N times):
+ LOOP (until any stop condition met):
1. REVIEW git log --oneline -10 + read results.tsv tail
Know what worked, what failed, what's untried.
- 2. IDEATE Pick ONE change. Write a one-sentence description
- BEFORE touching any code. Consult git history -
+ 2. IDEATE Pick UP TO `Batch` independent changes. Each must stand on
+ its own and be applicable independently. Write a one-sentence
+ description per change BEFORE touching code. Consult git history -
don't repeat discarded approaches.
- 3. MODIFY Make ONE atomic change to in-scope files only.
- Small, focused, explainable.
+ 3. MODIFY+COMMIT
+ For each change in the batch (in order):
+ a. Apply the change to in-scope files only.
+ b. git add <specific files> (never git add -A)
+ c. git commit -m "experiment: <one-line description>"
+ Each change is its own commit. Non-negotiable - bisection
+ depends on it.
- 4. COMMIT git add <specific files> (never git add -A)
- git commit -m "experiment: <description>"
- Commit BEFORE verification. Enables clean rollback.
+ 4. VERIFY Run the verify command after the final commit of the batch.
+ Extract the metric. If guard is set, run it too.
- 5. VERIFY Run the verify command. Extract the metric.
- If guard is set and metric improved, run guard too.
+ 5. DECIDE
+ Improved + guard ok (or no guard)
+ -> KEEP entire batch
+ Regressed / unchanged / guard failed:
+ if Batch == 1 -> REVERT the one commit
+ if Batch > 1 -> BISECT (see below)
+ Crashed (verify or guard non-zero exit, not just regressed)
+ -> attempt fix (max 3 tries), else REVERT entire batch
- 6. DECIDE
- Improved + guard passes (or no guard) -> KEEP
- Improved + guard fails -> REVERT (git revert HEAD --no-edit)
- Same or worse -> REVERT
- Crashed -> attempt fix (max 3 tries), else REVERT
+ 6. LOG Append one row per change to results.tsv.
- 7. LOG Append row to results.tsv
+ 7. SNAPSHOT If the new metric beats the previous best, force-update tag:
+ git tag -f iterate/best
- 8. REPEAT Go to 1. Print a one-line status every 5 iterations.
+ 8. CHECK STOP
+ Iterations cap reached? -> stop, summarize, exit.
+ Until target crossed? -> stop, summarize, exit.
+ Stagnation N reached? -> stop, summarize, exit.
+ Interrupted / fatal error? -> stop, summarize, exit.
+
+ 9. REPEAT Go to 1. Print a one-line status every 5 iterations.
NEVER ask "should I continue?" - just keep going.
- If bounded and iteration N reached, print summary and stop.
```
+ ### Bisection (Batch > 1, regression detected)
+
+ When a batched verify fails, the loop must identify which commit(s) caused the regression - keeping the good ones, dropping the bad ones.
+
+ ```
+ 1. Note C0 = the iteration's start commit (before the batch)
+ Note C1..CN = the batch commits in order
+
+ 2. git reset --hard C0
+
+ 3. For each Ci in order:
+ a. git cherry-pick Ci
+ b. Run verify
+ c. Improved or held + guard ok -> keep (commit stays in history)
+ Regressed or guard failed -> git reset --hard HEAD~1 (drop)
+
+ 4. Log each change's outcome to results.tsv:
+ status=bisect-keep -> commit kept
+ status=bisect-drop -> commit dropped
+ ```
+
+ **Cost**: worst case is N additional verify runs (1 batch + N individual). For `Batch: 3`, max 4 verifies. Worth it when batches are mostly good - i.e., when you're confident in the domain.
+
+ **Rule of thumb**: use `Batch: 1` for exploratory work, `Batch: 3-5` for mechanical fixes (lint, obvious test gaps, dead code), `Batch: 5+` only when you've watched the loop succeed at smaller batches first.
+
### Rollback
- Always use `git revert HEAD --no-edit` (preserves the experiment in history - the agent can learn from it). If revert conflicts, fall back to `git reset --hard HEAD~1`.
+ For single-commit reverts: `git revert HEAD --no-edit` (preserves the experiment in history). If revert conflicts, fall back to `git reset --hard HEAD~1`.
- ### When Stuck (5+ consecutive discards)
+ For batch reverts (full crash): `git reset --hard <iteration-start-commit>` - drops all batch commits cleanly.
+ ### Best Snapshot
+
+ `iterate/best` is a force-updated tag pointing to the highest-metric commit so far. It floats forward whenever a new best is reached.
+
+ - Recovery from any later regression: `git checkout iterate/best`
+ - Inspect what's pinned: `git log iterate/best -1`
+ - The skill never deletes the tag - clear manually with `git tag -d iterate/best`
+
+ The tag is updated *after* the SNAPSHOT step, so it always reflects the best state visible in `results.tsv`.
+
+ ### When Stuck (5+ consecutive discards or stagnation watermark)
+
1. Re-read ALL in-scope files from scratch
2. Re-read the original goal
3. Review entire results.tsv for patterns
4. Try combining two previously successful changes
5. Try the opposite of what hasn't been working
6. Try something radical - architectural changes, different algorithms
+ If `Stagnation: N` is set and reached, the loop will stop on its own. The "when stuck" protocol fires earlier (5 discards) as a course correction before the formal stop fires.
+
## Rules
- 1. **One change per iteration.** Atomic. If it breaks, you know exactly why.
+ 1. **One change per commit.** With `Batch: 1`, one change per iteration. With `Batch: N`, N commits per iteration - each independently bisectable. The atomicity invariant lives at the commit, not the iteration.
2. **Mechanical verification only.** No "looks good." The number decides.
3. **Git is memory.** Commit before verify. Revert on failure. Read `git log` before ideating. Failed experiments stay visible in history via revert commits.
4. **Simpler wins.** Equal metric + less code = keep. Tiny improvement + ugly complexity = discard. Removing code for equal results is a win.
- 5. **Never stop.** Unbounded loops run until interrupted. Never ask permission to continue. The user may be asleep.
- 6. **Read before write.** Understand full context before each modification.
- 7. **Scope is sacred.** Only modify files matching the scope globs. Never touch verify/guard targets, test fixtures, or config outside scope.
+ 5. **Never stop early.** Unbounded loops run until interrupted or a stop condition fires. Never ask permission to continue.
+ 6. **Always summarize on exit.** When the loop ends for any reason - bounded completion, target reached, stagnation, interrupt, or fatal error - emit the final summary block before yielding control. The user might be asleep; they'll read it in the morning.
+ 7. **Read before write.** Understand full context before each modification.
+ 8. **Scope is sacred.** Only modify files matching the scope globs. Never touch verify/guard targets, test fixtures, or config outside scope.
## Results Log
Tab-separated file: `results.tsv`
```tsv
iteration commit metric status description
0 a1b2c3d 72.3 baseline initial state
1 b2c3d4e 74.1 keep add edge case tests for auth module
2 - 73.8 discard refactor test helpers (broke coverage)
- 3 c3d4e5f 75.0 keep add missing null checks in user service
+ 3.1 c3d4e5f 74.6 bisect-keep add null check in user service
+ 3.2 - 74.6 bisect-drop rename helper module (regressed)
+ 3.3 d4e5f6a 75.0 bisect-keep add tests for token expiry
4 - 0.0 crash switched to vitest (import errors)
```
- **Status values:** `baseline`, `keep`, `discard`, `crash`
+ **Status values**: `baseline`, `keep`, `discard`, `bisect-keep`, `bisect-drop`, `crash`
+ **Iteration column**: integer for atomic iterations (`Batch: 1`), `<iter>.<change>` decimal for batched iterations (one row per change in the batch).
+
### Progress Output
Every 5 iterations, print a brief status:
```
- Iteration 15: metric 81.2 (baseline 72.3, +8.9) | 6 keeps, 8 discards, 1 crash
+ Iter 15: metric 81.2 (baseline 72.3, +8.9, best 81.2) | 6 keeps, 8 discards, 1 crash | stagnation 0/15
```
- When a bounded loop completes:
+ ### Final Summary (always emitted on exit)
+ Whatever causes the stop - bounded completion, `Until` target, `Stagnation` cap, interrupt, fatal - print this block before yielding control:
+
```
- === Iterate Complete (25/25) ===
- Baseline: 72.3 -> Final: 88.7 (+16.4)
- Keeps: 12 | Discards: 11 | Crashes: 2
- Best iteration: #18 - add integration tests for payment flow (+3.2)
+ === Iterate Complete ===
+ Stopped: target reached (Until ≥ 90.0)
+ Iterations: 23
+ Baseline: 72.3 -> Final 90.4 (+18.1)
+ Best: 90.4 @ iter 22 ("add integration tests for payment flow")
+ Keeps: 14 | Discards: 8 | Crashes: 1
+ Branch: iterate/increase-test-coverage-to-90
+ Tag: iterate/best -> 7f8a9b2
+
+ Next: review the branch, then merge / PR / cherry-pick / discard at your discretion.
+ Recovery from regression: git checkout iterate/best
```
+ The "Stopped" line names the trigger. Common values: `bounded completion`, `target reached`, `stagnation cap`, `user interrupt`, `fatal error`.
+
## Adapting to Any Domain
- The pattern is universal. Change the five inputs, not the loop.
+ The pattern is universal. Change the inputs, not the loop.
| Domain | Goal | Verify | Direction |
|--------|------|--------|-----------|
| Test coverage | Coverage to 90% | `npm test -- --coverage` | higher |
| Bundle size | Below 200KB | `npm run build && stat -f%z dist/main.js` | lower |
| Performance | Faster API response | `npm run bench \| grep p95` | lower |
| ML training | Lower validation loss | `uv run train.py && grep val_bpb run.log` | lower |
| Lint errors | Zero warnings | `npm run lint 2>&1 \| grep -c warning` | lower |
| Lighthouse | Score above 95 | `npx lighthouse --output=json \| jq .score` | higher |
| Code quality | Reduce complexity | `npx complexity-report \| grep average` | lower |
## Guard: Preventing Regressions
The guard is an optional safety net - a command that must always pass regardless of what the main metric does.
- **Verify** answers: "Did the metric improve?"
- **Guard** answers: "Did anything else break?"
- If the metric improves but the guard fails, the change is reverted. The agent should note WHY the guard failed and adapt future attempts accordingly.
+ If the metric improves but the guard fails, the change is reverted (or bisected, in batch mode). The agent should note WHY the guard failed and adapt future attempts accordingly.
Common guards: `npm test`, `tsc --noEmit`, `cargo check`, `pytest`, `go vet`
## Usage Examples
- ### Inline config (all fields provided)
+ ### Inline config — full overnight run with target
```
/iterate
Goal: Increase test coverage from 72% to 90%
Scope: src/**/*.ts, src/**/*.test.ts
Verify: npm test -- --coverage | grep "All files" | awk '{print $10}'
Direction: higher
Guard: tsc --noEmit
- Iterations: 30
+ Until: 90
+ Stagnation: 15
+ Batch: 3
+ Branch: auto
```
- ### Minimal (triggers interactive setup)
+ Runs until coverage hits 90% OR 15 consecutive iterations show no improvement, whichever first. 3 changes per iteration, bisected on regression. Lands on its own branch.
+ ### Bounded throughput run — mechanical fixes
+
```
/iterate
+ Goal: Reduce lint warnings to zero
+ Scope: src/**/*.ts
+ Verify: npm run lint 2>&1 | grep -c warning
+ Direction: lower
+ Until: 0
+ Iterations: 50
+ Batch: 5
+ ```
+
+ High-confidence mechanical fixes - batch aggressively. Stops at zero warnings or 50 iterations. Stays on current branch.
+
+ ### Minimal — interactive setup
+
+ ```
+ /iterate
Goal: Make the API faster
```
- Agent scans codebase for tooling, suggests scope/verify/direction, asks once, then goes.
+ Agent scans codebase, suggests scope/verify/direction, asks once, then goes. Defaults: `Batch: 1`, `Branch: current`, unbounded.
- ### Unbounded overnight run
+ ### Unbounded overnight, atomic, isolated branch
```
/iterate
Goal: Reduce bundle size below 150KB
Scope: src/**/*.ts, webpack.config.js
Verify: npm run build 2>&1 | grep "main.js" | awk '{print $2}'
Direction: lower
+ Branch: auto
```
- Agent runs indefinitely. User interrupts in the morning. Results are in `results.tsv` and git history.
+ Runs indefinitely on `iterate/reduce-bundle-size-below-150kb`. User interrupts in the morning, reads the summary, decides whether to merge.