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Get Started Free →Scans an existing codebase and generates project-specific skills that capture inferred conventions such as naming, file organization, framework usage, data access, error handling, and testing style. Writes into the project's chosen skill directory (e.g., `.claude/skills/`, `.agents/skills/`, or a custom path). Use when the user asks to "extract skills from the codebase", "create project skills", "infer project conventions as skills", "codify patterns as skills", or "mine the repo for best practi
.claude/skills/tobihagemann-create-project-skills/SKILL.md| Test case | Without → With | Effect | Δ tokens | Δ turns |
|---|---|---|---|---|
| case-07 | ✗→✓ | ▲ Improved | 62% | 0% |
| case-08 | ✗→✓ | ▲ Improved | 44% | 0% |
| case-12 | ✗→✓ | ▲ Improved | 60% | 0% |
| case-13 | ✗→✓ | ▲ Improved | 50% | 0% |
| case-17 | ✗→✓ | ▲ Improved | 79% | 0% |
Generates one skill per detected convention area in the project's skill directory so future Claude or Codex sessions auto-load them when working in the repo.
At the start, use update_plan to track each phase, restating any remaining steps of a parent workflow alongside them:
$create-skill skillIf $ARGUMENTS specifies paths, scope the scan to those paths; otherwise scan the whole repository.
Build the extraction context:
package.json, Cargo.toml, pyproject.toml, go.mod, Package.swift, pom.xml, Gemfile, and others appropriate to the stack).AGENTS.override.md when one is present, otherwise AGENTS.md, including nested ones) and any .cursor/rules or .cursorrules. Note the conventions already documented there. The generated skills must not duplicate them..agents/skills/, .claude/skills/, and a top-level skills/ directory (match case-insensitively so Skills/ or similar non-standard casing is detected too). Resolve symlinks so co-linked paths are treated as one logical location.request_user_input to confirm where generated skills should live. Offer up to 3 options: the most likely target directory first, the next-most-likely if there is one, and a free-form path option. Note any symlink alias in the option description. If no Codex skill directory is detected, default the first option to ~/.agents/skills. The user can specify a custom path such as a project-specific directory via the free-form option.## section heading from the body. These signals feed rename-conflict detection in Step 3.Output a short text summary of detected stack, top-level layout, chosen target directory, and existing skills before moving on.
When that summary shows no source code to extract conventions from, stop here rather than dispatching Step 2. Executable code in any language qualifies, including scripts no manifest declares, so judge from the directory map rather than the detected stack. Documentation, instruction files, and configuration alone do not: extraction run over prose returns that prose's assertions as observed conventions, and Step 3 scores them with no code sites to test them against.
State that as text first — what the survey found, and that conventions extracted from it would have nothing to verify against. Then use request_user_input to offer:
On the first option, run the $create-skill skill directly on that knowledge and skip the remaining steps. On either of the first two, call update_plan with the extraction phases removed so they no longer read as pending work.
Read references/pattern-extractor.md to see the full taxonomy of pattern categories. Decide which categories apply to the detected stack (e.g., drop "Styling and UI" for a backend service, drop "State management" for a static-analysis tool).
Issue one extraction spawn_agent call per applicable category, all in one batch, then collect their results with wait_agent. Do not issue one and await its result before issuing the rest. Each sub-agent inherits the parent model. State the total count explicitly before emitting the batch. Every sub-agent's prompt must direct it to treat the shared working tree and its git index as read-only and to extract by reading and reasoning. HEAD stays where it is: read other refs with git show <ref>:<path> rather than git checkout or git switch. Each agent's prompt must:
AGENTS.md so duplicates are skippedAggregate findings from all agents. For each finding, score three axes:
Group the surviving findings by topic into candidate skills. Each candidate typically covers one category, but related categories may merge if the patterns are tightly coupled. Split a candidate into two skills if its patterns cover clearly distinct sub-topics.
For each candidate skill, produce:
name (kebab-case, narrow to the topic, e.g., swift-naming, react-state, api-clients)file:line)If rename-conflict detection is ambiguous from the Step 1 signals alone, read the existing skill's SKILL.md body and compare convention statements before finalizing the Status tag.
Output the full proposal as text first, not inside request_user_input. For each candidate skill, show:
After all candidates are listed, use request_user_input to confirm the proposal with these options: "Approve all", "Make edits", "Cancel". If the user selects "Make edits", continue in conversation so the user can specify which candidates to drop, merge, or rename before returning here.
For each Rename conflict candidate, use a separate request_user_input asking whether to update the existing skill, create the new one alongside it, or skip. Since creating alongside always establishes a second skill covering the same conventions, present a Get a second opinion option in place of skip, keeping the question at three options. It runs the $consult-claude skill for which resolution leaves the skill set coherent. Then resolve the conflict with that answer in hand, re-asking when the choice stays the user's. A freeform answer that declines the candidate skips it.
$create-skill SkillBuild the batch from approved candidates only. Do not include anything not explicitly approved in Step 4.
Output all approved candidates (both New and Update status) as text in a single batch. For each candidate, list the Status tag, proposed name, description, target path <target-skill-directory>/<name>/SKILL.md, and the 3–8 convention statements organized under ## <Section> headings with inline evidence citations (file_path:line). These convention statements define the target state the final SKILL.md should match, regardless of whether the skill is being created or updated.
This gives $create-skill everything it needs to skip its Step 1 (usage patterns clearly understood) and Step 2 (project skills typically need no additional reusable resources). For Update candidates, $create-skill also skips its Step 3 (initialization) per its own "skill already exists, iteration needed" skip rule and iterates on the existing SKILL.md in Step 4 until it matches the target convention statements.
Run the $create-skill skill once with this batch in context. Its batch-aware review, evaluation, and apply cycle then runs across all touched skills.
After $create-skill completes, output a summary of created and updated skills, grouped by status. If any candidates were dropped or skipped in Step 4, list them so the user knows what was left out.
AGENTS.md. Reference them instead if needed.| Case | Status | Duration (ms) | Turns | Tokens | Tool calls | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Without | With | Δ | Without | With | Δ | Without | With | Δ | Without | With | Δ | ||
case-01 | fail→fail | 2,253 | 36,626 | +1526% | 1 | 1 | 0% | 256 | 2,551 | +896% | 0 | 0 | — |
case-02 | fail→fail | 3,435 | 7,382 | +115% | 1 | 1 | 0% | 474 | 2,820 | +495% | 0 | 0 | — |
case-03 | fail→fail | 3,895 | 7,217 | +85% | 1 | 1 | 0% | 311 | 2,686 | +764% | 0 | 0 | — |
case-04 | pass→fail | 11,760 | 28,207 | +140% | 1 | 1 | 0% | 1,583 | 2,953 | +87% | 0 | 0 | — |
case-05 | fail→fail | 4,352 | 34,059 | +683% | 1 | 1 | 0% | 254 | 2,686 | +957% | 0 | 0 | — |
case-06 | fail→fail | 2,588 | 31,209 | +1106% | 1 | 1 | 0% | 467 | 3,400 | +628% | 0 | 0 | — |
case-07 | fail→pass | 8,984 | 2,501 | -72% | 1 | 1 | 0% | 1,643 | 2,667 | +62% | 0 | 0 | — |
case-08 | fail→pass | 12,199 | 3,175 | -74% | 1 | 1 | 0% | 1,927 | 2,771 | +44% | 0 | 0 | — |
case-09 | pass→pass | 11,091 | 4,863 | -56% | 1 | 1 | 0% | 1,892 | 3,047 | +61% | 0 | 0 | — |
case-10 | pass→pass | 4,211 | 2,607 | -38% | 1 | 1 | 0% | 759 | 2,701 | +256% | 0 | 0 | — |
case-11 | fail→fail | 8,133 | 2,657 | -67% | 1 | 1 | 0% | 1,488 | 2,613 | +76% | 0 | 0 | — |
case-12 | fail→pass | 9,606 | 3,860 | -60% | 1 | 1 | 0% | 1,809 | 2,903 | +60% | 0 | 0 | — |
case-13 | fail→pass | 10,869 | 2,844 | -74% | 1 | 1 | 0% | 1,759 | 2,638 | +50% | 0 | 0 | — |
case-14 | pass→pass | 8,557 | 1,927 | -77% | 1 | 1 | 0% | 1,430 | 2,502 | +75% | 0 | 0 | — |
case-15 | pass→pass | 9,110 | 2,694 | -70% | 1 | 1 | 0% | 1,630 | 2,671 | +64% | 0 | 0 | — |
case-16 | pass→pass | 11,577 | 2,713 | -77% | 1 | 1 | 0% | 2,027 | 2,696 | +33% | 0 | 0 | — |
case-17 | fail→pass | 10,347 | 5,521 | -47% | 1 | 1 | 0% | 1,817 | 3,248 | +79% | 0 | 0 | — |
case-18 | fail→pass | 9,090 | 4,196 | -54% | 1 | 1 | 0% | 1,711 | 3,054 | +78% | 0 | 0 | — |
case-19 | pass→fail | 9,314 | 3,846 | -59% | 1 | 1 | 0% | 1,715 | 2,919 | +70% | 0 | 0 | — |
case-20 | fail→pass | 5,590 | 2,580 | -54% | 1 | 1 | 0% | 942 | 2,681 | +185% | 0 | 0 | — |
case-21 | fail→fail | 9,416 | 2,825 | -70% | 1 | 1 | 0% | 1,570 | 2,752 | +75% | 0 | 0 | — |
case-22 | fail→pass | 9,440 | 5,069 | -46% | 1 | 1 | 0% | 1,634 | 3,194 | +95% | 0 | 0 | — |
DecimalAI ran this skill against gemini-3.6-flash twice over the same eval suite — once with the skill loaded and once without — and compared the two runs case by case. 22 cases were attempted, and 16 counted toward the lift figure. The other 6 produced results that are not comparable between the two arms, so they are excluded from the headline rather than averaged into it. The headline lift of +27 percentage points is the difference between those two pass rates over the 16 comparable cases. 3 cases got worse with the skill loaded, and they are included in that figure.
Without the skill loaded, the model failed this case. With it loaded, the same prompt on the same model passed. This is one improved case from the latest verified run; every case, including any that regressed, is in the table above.
| Model | Method | Date | Lift |
|---|---|---|---|
| gemini-3.6-flash | verified | 8/21/2026 | +18% |
Other measured skills in the registry, with their headline benchmark lift.