INIT=$(gsd-sdk query init.phase-op "${PHASE_ARG}")
if [[ "$INIT" == @file:* ]]; then INIT=$(cat "${INIT#@file:}"); fi
Parse from init JSON: phase_found, phase_dir, phase_number, phase_name, padded_phase.
If phase not found, exit with error: "Phase {PHASE_ARG} not found."
Required artifacts:
${PHASE_DIR}/*-PLAN.md— all plan files for the phase${PHASE_DIR}/*-SUMMARY.md— all summary files for the phase
If PLAN.md or SUMMARY.md files are not found or missing, exit with error: "Required artifacts missing. PLAN.md and SUMMARY.md are required for learning extraction."
Optional artifacts (read if available, skip if not found):
${PHASE_DIR}/*-VERIFICATION.md— verification results${PHASE_DIR}/*-UAT.md— user acceptance test results.planning/STATE.md— project state with decisions and blockers
Track which optional artifacts are missing for the missing_artifacts frontmatter field.
1. Decisions
Technical and architectural decisions made during the phase. Look for:
- Explicit decisions documented in PLAN.md or SUMMARY.md
- Technology choices and their rationale
- Trade-offs that were evaluated
- Design decisions recorded in STATE.md
Each decision entry must include:
- What was decided
- Why it was decided (rationale)
- Source: attribution to the artifact where the decision was found (e.g., "Source: 03-01-PLAN.md")
2. Lessons
Things learned during execution that were not known beforehand. Look for:
- Unexpected complexity in SUMMARY.md
- Issues discovered during verification in VERIFICATION.md
- Failed approaches documented in SUMMARY.md
- UAT feedback that revealed gaps
Each lesson entry must include:
- What was learned
- Context for the lesson
- Source: attribution to the originating artifact
3. Patterns
Reusable patterns, approaches, or techniques discovered. Look for:
- Successful implementation patterns in SUMMARY.md
- Testing patterns from VERIFICATION.md or UAT.md
- Workflow patterns that worked well
- Code organization patterns from PLAN.md
Each pattern entry must include:
- Pattern name/description
- When to use it
- Source: attribution to the originating artifact
4. Surprises
Unexpected findings, behaviors, or outcomes. Look for:
- Things that took longer or shorter than estimated
- Unexpected dependencies or interactions
- Edge cases not anticipated in planning
- Performance or behavior that differed from expectations
Each surprise entry must include:
- What was surprising
- Impact of the surprise
- Source: attribution to the originating artifact
Detection: Check whether a tool named capture_thought is available in the current session. Do not assume any specific MCP server is connected.
If available, call once per extracted learning:
capture_thought({
category: "decision" | "lesson" | "pattern" | "surprise",
phase: PHASE_NUMBER,
content: LEARNING_TEXT,
source: ARTIFACT_NAME
})
If not available (no MCP server in the session exposes this tool, or the runtime does not support it), skip the step silently and continue. The workflow must not fail or warn — this is expected behavior for users who do not run a knowledge-base MCP.
Output path: ${PHASE_DIR}/${PADDED_PHASE}-LEARNINGS.md
The file must have YAML frontmatter with these fields:
---
phase: {PHASE_NUMBER}
phase_name: "{PHASE_NAME}"
project: "{PROJECT_NAME}"
generated: "{ISO_DATE}"
counts:
decisions: {N}
lessons: {N}
patterns: {N}
surprises: {N}
missing_artifacts:
- "{ARTIFACT_NAME}"
---
Individual items may carry an optional graduated: annotation (added by graduation.md when a cluster is promoted):
**Graduated:** {target-file}:{ISO_DATE}
This annotation is appended after the item's existing fields and prevents the item from being re-surfaced in future graduation scans. Do not add this field during extraction — it is written only by the graduation workflow.
The body follows this structure:
# Phase {PHASE_NUMBER} Learnings: {PHASE_NAME}
## Decisions
### {Decision Title}
{What was decided}
**Rationale:** {Why}
**Source:** {artifact file}
---
## Lessons
### {Lesson Title}
{What was learned}
**Context:** {context}
**Source:** {artifact file}
---
## Patterns
### {Pattern Name}
{Description}
**When to use:** {applicability}
**Source:** {artifact file}
---
## Surprises
### {Surprise Title}
{What was surprising}
**Impact:** {impact description}
**Source:** {artifact file}
gsd-sdk query state.update "Last Activity" "$(date +%Y-%m-%d)"
Learnings Extracted: Phase {X} — {Name}
Decisions: {N} Lessons: {N} Patterns: {N} Surprises: {N} Total: {N}
Output: {PHASE_DIR}/{PADDED_PHASE}-LEARNINGS.md
Missing artifacts: {list or "none"}
Next steps:
- Review extracted learnings for accuracy
- /gsd-progress — see overall project state
- /gsd-execute-phase {next} — continue to next phase
</step>
</process>
<success_criteria>
- [ ] Phase artifacts located and read successfully
- [ ] All 4 categories extracted: decisions, lessons, patterns, surprises
- [ ] Each extracted item has source attribution
- [ ] LEARNINGS.md written with correct YAML frontmatter
- [ ] Missing optional artifacts tracked in frontmatter
- [ ] capture_thought integration attempted if tool available
- [ ] STATE.md updated with extraction activity
- [ ] User receives summary report
</success_criteria>
<critical_rules>
- PLAN.md and SUMMARY.md are required — exit with clear error if missing
- VERIFICATION.md, UAT.md, and STATE.md are optional — extract from them if present, skip gracefully if not found
- Every extracted learning must have source attribution back to the originating artifact
- Running extract-learnings twice on the same phase must overwrite (replace) the previous LEARNINGS.md, not append
- Do not fabricate learnings — only extract what is explicitly documented in artifacts
- If capture_thought is unavailable, the workflow must not fail — graceful degradation to file-only output
- LEARNINGS.md frontmatter must include counts for all 4 categories and list any missing_artifacts
</critical_rules>