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+# Workflow Schema Optimization Plan
+
+## Current State (Commit 7660f61)
+
+### What's Implemented
+
+1. **Original schema preserved**: `workflow-v1.0.json` remains source of truth with 291 definitions
+2. **Optimization script**: `script/optimize-workflow-schema.js` prunes unused definitions
+3. **Generated files** (gitignored):
+   - `workflow-v1.0.optimized.json` - 281 definitions (pruned)
+   - `workflow-v1.0.optimized.min.json` - minified version loaded at runtime
+4. **Build pipeline**: `npm run minify-json` chains optimize → minify
+5. **Tests**: `workflow-schema.test.ts` validates schema integrity
+
+### 10 Pruned Definitions
+
+These are unreachable from `workflow-root-strict` entry point:
+
+- `workflow-root` (non-strict variant)
+- `on` (non-strict variant)
+- `on-mapping` (non-strict variant)
+- `job-if-result`
+- `step-if-result`
+- `boolean-needs-context`
+- `number-needs-context`
+- `string-needs-context`
+- `boolean-steps-context`
+- `number-steps-context`
+
+### Size Savings
+
+| Metric | Original | Optimized | Savings |
+|--------|----------|-----------|---------|
+| Definitions | 291 | 281 | 10 removed |
+| Minified | 71,061 B | 69,022 B | 2.9% |
+| Gzipped | 12,318 B | 12,172 B | 1.2% |
+
+## Optimization Strategies Evaluated
+
+### ✅ Pruning Unused Definitions (IMPLEMENTED)
+- Removes definitions not reachable from entry point
+- 1.2% gzip savings
+- Low complexity, no runtime overhead
+
+### ❌ Key Shortening
+- Replace long keys with short codes (e.g., `description` → `d`)
+- 1.5% gzip savings
+- NOT WORTH IT: Adds complexity, minimal benefit after gzip
+
+### ❌ String Interning
+- Deduplicate repeated strings into lookup table
+- Makes gzip WORSE (-0.5%)
+- NOT WORTH IT: Gzip already handles repetition
+
+### ❌ Compact Format (like webhooks)
+- Restructure to array-based format
+- Makes gzip WORSE (-0.4%)
+- NOT WORTH IT: Schema structure doesn't benefit
+
+### ❌ Split Descriptions
+- Separate file for descriptions
+- Adds 791 bytes when both files gzipped
+- NOT WORTH IT: Worse total size
+
+## Future Work
+
+### Update from Server
+The current schema may be missing some definitions from the latest server version. A future PR should:
+1. Fetch latest `workflow-v1.0.json` from dotcom server
+2. Update the source file
+3. Verify tests still pass
+4. Note: Server version had issues last checked (e.g., `coerce-raw`, missing `branches` on merge-group)
+
+### Entry Point
+- Entry point: `workflow-root-strict` (defined in `workflow-constants.ts`)
+- Non-strict `workflow-root` exists but is unused in this codebase
+
+## Files
+
+```
+workflow-parser/
+├── src/
+│   ├── workflow-v1.0.json              # Source of truth (tracked, 291 defs)
+│   ├── workflow-v1.0.optimized.json    # Pruned (gitignored, 281 defs)
+│   ├── workflow-v1.0.optimized.min.json # Minified (gitignored)
+│   └── workflows/
+│       ├── workflow-schema.ts          # Loader (imports optimized.min.json)
+│       └── workflow-schema.test.ts     # Schema integrity tests
+└── script/
+    └── optimize-workflow-schema.js     # Pruning script
+```
+
+## Test Coverage
+
+- `workflow-schema.test.ts`:
+  1. Schema loads from workflow-root-strict
+  2. All referenced definitions are reachable
+  3. Critical definitions exist (jobs, steps, runs-on, etc.)