diff --git a/get-shit-done/templates/summary.md b/get-shit-done/templates/summary.md
index 1b17475f4..7e7677f27 100644
--- a/get-shit-done/templates/summary.md
+++ b/get-shit-done/templates/summary.md
@@ -7,6 +7,44 @@ Template for `.planning/phases/XX-name/{phase}-{plan}-SUMMARY.md` - phase comple
 ## File Template
 
 ```markdown
+---
+phase: XX-name
+plan: YY
+subsystem: [primary category: auth, payments, ui, api, database, infra, testing, etc.]
+tags: [searchable tech: jwt, stripe, react, postgres, prisma]
+
+# Dependency graph
+requires:
+  - phase: [prior phase this depends on]
+    provides: [what that phase built that this uses]
+provides:
+  - [bullet list of what this phase built/delivered]
+affects: [list of phase names or keywords that will need this context]
+
+# Tech tracking
+tech-stack:
+  added: [libraries/tools added in this phase]
+  patterns: [architectural/code patterns established]
+
+key-files:
+  created: [important files created]
+  modified: [important files modified]
+
+key-decisions:
+  - "Decision 1"
+  - "Decision 2"
+
+patterns-established:
+  - "Pattern 1: description"
+  - "Pattern 2: description"
+
+issues-created: [ISS-XXX, ISS-YYY] # From ISSUES.md if any
+
+# Metrics
+duration: Xmin
+completed: YYYY-MM-DD
+---
+
 # Phase [X]: [Name] Summary
 
 **[Substantive one-liner describing outcome - NOT "phase complete" or "implementation finished"]**
@@ -74,6 +112,24 @@ Logged to .planning/ISSUES.md for future consideration:
 *Completed: [date]*
 ```
 
+<frontmatter_guidance>
+**Purpose:** Enable automatic context assembly via dependency graph. Frontmatter makes summary metadata machine-readable so plan-phase can scan all summaries quickly and select relevant ones based on dependencies.
+
+**Fast scanning:** Frontmatter is first ~25 lines, cheap to scan across all summaries without reading full content.
+
+**Dependency graph:** `requires`/`provides`/`affects` create explicit links between phases, enabling transitive closure for context selection.
+
+**Subsystem:** Primary categorization (auth, payments, ui, api, database, infra, testing) for detecting related phases.
+
+**Tags:** Searchable technical keywords (libraries, frameworks, tools) for tech stack awareness.
+
+**Key-files:** Important files for @context references in PLAN.md.
+
+**Patterns:** Established conventions future phases should maintain.
+
+**Population:** Frontmatter is populated during summary creation in execute-phase.md. See `<step name="create_summary">` for field-by-field guidance.
+</frontmatter_guidance>
+
 <one_liner_rules>
 The one-liner MUST be substantive:
 
@@ -173,6 +229,11 @@ Logged to .planning/ISSUES.md for future consideration:
 - Required output from execute-phase workflow
 - Documents what actually happened vs what was planned
 
+**Frontmatter completion:**
+- MANDATORY: Complete all frontmatter fields during summary creation
+- See <frontmatter_guidance> for field purposes
+- Frontmatter enables automatic context assembly for future planning
+
 **One-liner requirements:**
 - Must be substantive (describe what shipped, not "phase complete")
 - Should tell someone what was accomplished
diff --git a/get-shit-done/workflows/execute-phase.md b/get-shit-done/workflows/execute-phase.md
index 83e46f8c7..2a70b30ed 100644
--- a/get-shit-done/workflows/execute-phase.md
+++ b/get-shit-done/workflows/execute-phase.md
@@ -990,6 +990,41 @@ Use ~/.claude/get-shit-done/templates/summary.md for structure.
 
 **File location:** `.planning/phases/XX-name/{phase}-{plan}-SUMMARY.md`
 
+**Frontmatter population:**
+
+Before writing summary content, populate frontmatter fields from execution context:
+
+1. **Basic identification:**
+   - phase: From PLAN.md frontmatter
+   - plan: From PLAN.md frontmatter
+   - subsystem: Categorize based on phase focus (auth, payments, ui, api, database, infra, testing, etc.)
+   - tags: Extract tech keywords (libraries, frameworks, tools used)
+
+2. **Dependency graph:**
+   - requires: List prior phases this built upon (check PLAN.md context section for referenced prior summaries)
+   - provides: Extract from accomplishments - what was delivered
+   - affects: Infer from phase description/goal what future phases might need this
+
+3. **Tech tracking:**
+   - tech-stack.added: New libraries from package.json changes or requirements
+   - tech-stack.patterns: Architectural patterns established (from decisions/accomplishments)
+
+4. **File tracking:**
+   - key-files.created: From "Files Created/Modified" section
+   - key-files.modified: From "Files Created/Modified" section
+
+5. **Decisions:**
+   - key-decisions: Extract from "Decisions Made" section
+
+6. **Issues:**
+   - issues-created: Check if ISSUES.md was updated during execution
+
+7. **Metrics:**
+   - duration: From $DURATION variable
+   - completed: From $PLAN_END_TIME (date only, format YYYY-MM-DD)
+
+Note: If subsystem/affects are unclear, use best judgment based on phase name and accomplishments. Can be refined later.
+
 **Title format:** `# Phase [X] Plan [Y]: [Name] Summary`
 
 The one-liner must be SUBSTANTIVE: