dx-pattern-extract

name: dx-pattern-extract description: Scan completed tickets for recurring patterns and promote to cross-ticket knowledge. Run periodically or after completing several tickets. Creates .ai/graph/nodes/patterns/ entries. when_to_use: "Use when scanning completed tickets for recurring patterns. Trigger on 'extract patterns', 'promote patterns', 'find recurring patterns', 'update cross-ticket knowledge', or 'run pattern extraction'." argument-hint: "[--dry-run (preview without writing)]" model: haiku effort: low allowed-tools: ["read", "search", "write"]

You scan all completed spec directories for recurring decisions and approaches, then promote patterns that appear in 3+ tickets to .ai/graph/nodes/patterns/ for cross-ticket knowledge reuse.

1. Scan Decision Sources

Collect decisions from two sources — structured YAML (preferred) and markdown fallback.

1a. Decision Nodes (primary source)

Scan for structured decision YAML files:

find .ai/graph/nodes/decisions/ -name "*.yaml" -type f 2>/dev/null

Read shared/decision-schema.md for the schema definition. For each decision YAML file, extract:

• ticket — the work item ID
• chosen — what was chosen
• tags — for grouping by similarity
• files — for matching by file overlap
• alternatives — the rejected options (useful for understanding the pattern's scope)
• status — skip decisions with status: superseded or status: rejected

1b. Implement.md fallback (for pre-Phase 4 tickets)

Find all spec directories with completed work:

find .ai/specs/ -name "implement.md" -type f 2>/dev/null

For each implement.md found, check if decision YAML files already exist for that ticket (by matching the ticket ID from the spec directory name against .ai/graph/nodes/decisions/<ticket>-*.yaml). If YAML files exist, skip the markdown scan for that ticket — the YAML is the authoritative source.

For tickets without decision YAML files, read from implement.md:

• The ## Key Decisions section (if present) — these are explicit design choices with alternatives
• The ## Approach section — the overall strategy
• The ## Steps section — scan step titles and file references for recurring patterns

Also read research.md from the same directory (if present):

• The ## Existing Implementation Check section — which existing code was reused
• The ## Key Findings section — important discoveries

Skip spec directories that have no implement.md or where all steps are still pending (ticket not yet worked on).

2. Identify Recurring Patterns

Group the extracted decisions and approaches by similarity. Two decisions are "the same pattern" when they share:

• Same architectural choice — e.g., "extend existing component" appears in multiple tickets
• Same file/class pattern — e.g., multiple tickets modify the same utility or follow the same model class pattern
• Same technology approach — e.g., multiple tickets use the same library, config pattern, or API pattern

Matching heuristics:

• Decisions that share tags values (from YAML) or reference the same files or directories
• Decisions with the same chosen approach (from YAML) or "Chosen" text (from markdown), even if wording differs
• Decisions with overlapping files lists (from YAML) — strong signal of the same pattern
• Steps that follow the same sequence (e.g., "modify model → update dialog → update template")
• Reused utilities or services that appear in 3+ tickets' Key Findings

Minimum threshold: A pattern must appear in 3 or more tickets to be promoted. Fewer occurrences may be coincidence.

3. Check Existing Patterns

Read all existing pattern files:

find .ai/graph/nodes/patterns/ -name "*.yaml" -type f 2>/dev/null

For each existing pattern:

• Check if new tickets should be added to its tickets: list
• Update updated: timestamp if new evidence found
• Do NOT create duplicates — merge into existing patterns

4. Write Pattern Nodes

Read shared/pattern-schema.md for the YAML schema.

Create the directory if it doesn't exist:

mkdir -p .ai/graph/nodes/patterns

For each newly identified pattern (3+ tickets, not already captured):

1. Generate a kebab-case topic slug from the pattern title
2. Write .ai/graph/nodes/patterns/<topic>.yaml following the schema exactly
3. Set confidence: medium, trust_tier: long-term
4. Include all tickets that contributed to the pattern

For existing patterns with new ticket evidence:

1. Read the existing YAML
2. Add new ticket entries to tickets:
3. Update updated: timestamp
4. If tickets count reaches 5+, consider upgrading confidence to high

Dry Run Mode

If --dry-run is passed as argument:

• Print what patterns would be created/updated
• Do NOT write any files
• Useful for previewing before committing to the graph

5. Present Summary

## Pattern Extraction Complete

**Specs scanned:** <count>
**Patterns found:** <count new> new, <count updated> updated

### New Patterns
| Pattern | Tickets | Tags |
|---------|---------|------|
| <title> | <count> | <tags> |

### Updated Patterns
| Pattern | New Tickets Added | Total |
|---------|------------------|-------|
| <title> | +<count> | <total> |

### Below Threshold (2 tickets — watching)
| Candidate | Tickets | Notes |
|-----------|---------|-------|
| <description> | <count> | Needs 1 more occurrence |

### Next steps:
- Patterns are now available for `/dx-plan` to reference
- Run `/dx-plan <id>` — it will check patterns automatically
- Review patterns in `.ai/graph/nodes/patterns/` for accuracy

Examples

First extraction (bootstrapping)

/dx-pattern-extract

Scans 12 completed specs, finds 3 patterns with 3+ ticket occurrences each. Creates .ai/graph/nodes/patterns/ with 3 YAML files. Reports 2 candidates below threshold.

Dry run preview

/dx-pattern-extract --dry-run

Same analysis but only prints what would be created. No files written.

Incremental update

/dx-pattern-extract

After completing 5 more tickets, re-run. Finds 1 new pattern, updates 2 existing patterns with new ticket evidence. Reports updated totals.

Rules

• 3-ticket minimum — never promote a pattern with fewer than 3 occurrences
• No speculation — only extract patterns from actual completed work, not hypothetical approaches
• Merge, don't duplicate — if a pattern already exists, add ticket evidence to it
• Concrete, not abstract — patterns must reference specific files, classes, or config keys. "Use existing utilities" is too vague; "Extend validateField() in src/core/scripts/libs/forms.js" is concrete.
• Tags for matching — include enough tags that dx-plan can find relevant patterns by keyword matching against research.md
• Preserve provenance — each ticket entry records HOW that ticket used the pattern, not just that it did
• Idempotent — running twice produces the same result (no duplicate patterns or ticket entries)