diff --git a/get-shit-done/references/plan-format.md b/get-shit-done/references/plan-format.md
index 91d058344..fd4127987 100644
--- a/get-shit-done/references/plan-format.md
+++ b/get-shit-done/references/plan-format.md
@@ -243,6 +243,43 @@ Use for: Technology selection, architecture decisions, design choices, feature p
 See `./checkpoints.md` for comprehensive checkpoint guidance.
 </task_types>
 
+<tdd_annotation>
+Tasks can include `tdd="true"` attribute when TDD improves quality:
+
+**Structure:**
+```xml
+<task type="auto" tdd="true">
+  <name>Task N: [Name]</name>
+  <files>[paths]</files>
+  <test-first>[What test to write first - the failing assertion]</test-first>
+  <action>[Implementation to make test pass]</action>
+  <verify>[Tests pass, behavior works]</verify>
+  <done>[Criteria]</done>
+</task>
+```
+
+**When to add tdd="true":**
+- Business logic with defined inputs/outputs
+- API endpoints with request/response contracts
+- Data transformations and parsing
+- Validation rules
+- Algorithms with testable behavior
+
+**When NOT to add tdd="true":**
+- UI layout and styling
+- Configuration changes
+- Glue code connecting existing components
+- One-off scripts
+
+**Execution flow (when tdd="true"):**
+1. Claude writes failing test from `<test-first>`
+2. Claude implements from `<action>` until test passes
+3. Claude refactors if needed (tests still pass)
+4. Claude commits atomic change
+
+See `./tdd.md` for comprehensive TDD guidance.
+</tdd_annotation>
+
 <context_references>
 Use @file references to load context for the prompt:
 
@@ -347,6 +384,26 @@ Claude: "How? What type? What library? Where?"
 Claude can implement this immediately.
 </just_right>
 
+<tdd_example>
+TDD task example:
+
+```xml
+<task type="auto" tdd="true">
+  <name>Task 2: Create email validation utility</name>
+  <files>src/lib/validation.ts, src/lib/validation.test.ts</files>
+  <test-first>
+    Test: isValidEmail returns true for valid emails, false for invalid
+    Cases: "user@example.com" → true, "invalid" → false, "" → false, "user@" → false
+  </test-first>
+  <action>Implement isValidEmail using regex pattern. Handle edge cases: empty string, missing @, missing domain.</action>
+  <verify>npm test -- validation.test.ts passes all cases</verify>
+  <done>Email validation works for all edge cases, tests document behavior</done>
+</task>
+```
+
+Claude executes this with RED → GREEN → REFACTOR cycle, producing atomic commits.
+</tdd_example>
+
 <too_detailed>
 Writing the actual code in the plan. Trust Claude to implement from clear instructions.
 </too_detailed>
diff --git a/get-shit-done/references/tdd.md b/get-shit-done/references/tdd.md
new file mode 100644
index 000000000..b913656a8
--- /dev/null
+++ b/get-shit-done/references/tdd.md
@@ -0,0 +1,168 @@
+<overview>
+TDD is about design quality, not coverage metrics. The red-green-refactor cycle forces you to think about behavior before implementation, producing cleaner interfaces and more testable code.
+
+**Principle:** If you can describe the behavior as `expect(fn(input)).toBe(output)` before writing `fn`, TDD improves the result.
+</overview>
+
+<detection>
+## When TDD Improves Quality
+
+**TDD candidates (add `tdd="true"`, include `<test-first>`):**
+- Business logic with defined inputs/outputs
+- API endpoints with request/response contracts
+- Data transformations, parsing, formatting
+- Validation rules and constraints
+- Algorithms with testable behavior
+- State machines and workflows
+- Utility functions with clear specifications
+
+**Skip TDD (standard `type="auto"`):**
+- UI layout, styling, visual components
+- Configuration changes
+- Glue code connecting existing components
+- One-off scripts and migrations
+- Simple CRUD with no business logic
+- Exploratory prototyping
+
+**Heuristic:** Can you write `expect(fn(input)).toBe(output)` before writing `fn`?
+→ Yes: TDD will help
+→ No: Implement first, add tests after if needed
+</detection>
+
+<execution_flow>
+## Red-Green-Refactor Cycle
+
+**RED - Write failing test:**
+1. Create test file following project conventions
+2. Write test describing expected behavior (from `<test-first>` element)
+3. Run test - it MUST fail
+4. If test passes: feature exists or test is wrong. Investigate.
+5. Commit: `test: add failing test for [feature]`
+
+**GREEN - Implement to pass:**
+1. Write minimal code to make test pass
+2. No cleverness, no optimization - just make it work
+3. Run test - it MUST pass
+4. Commit: `feat: implement [feature]`
+
+**REFACTOR (if needed):**
+1. Clean up implementation if obvious improvements exist
+2. Run tests - MUST still pass
+3. Only commit if changes made: `refactor: clean up [feature]`
+
+**Atomic commits:** Each TDD task produces 2-3 commits following this pattern.
+</execution_flow>
+
+<test_quality>
+## Good Tests vs Bad Tests
+
+**Test behavior, not implementation:**
+- Good: "returns formatted date string"
+- Bad: "calls formatDate helper with correct params"
+- Tests should survive refactors
+
+**One concept per test:**
+- Good: Separate tests for valid input, empty input, malformed input
+- Bad: Single test checking all edge cases with multiple assertions
+
+**Descriptive names:**
+- Good: "should reject empty email", "returns null for invalid ID"
+- Bad: "test1", "handles error", "works correctly"
+
+**No implementation details:**
+- Good: Test public API, observable behavior
+- Bad: Mock internals, test private methods, assert on internal state
+</test_quality>
+
+<framework_setup>
+## Test Framework Setup (If None Exists)
+
+When a TDD task exists but no test framework is configured:
+
+**1. Detect project type:**
+```bash
+# JavaScript/TypeScript
+if [ -f package.json ]; then echo "node"; fi
+
+# Python
+if [ -f requirements.txt ] || [ -f pyproject.toml ]; then echo "python"; fi
+
+# Go
+if [ -f go.mod ]; then echo "go"; fi
+
+# Rust
+if [ -f Cargo.toml ]; then echo "rust"; fi
+```
+
+**2. Install minimal framework:**
+| Project | Framework | Install |
+|---------|-----------|---------|
+| Node.js | Jest | `npm install -D jest @types/jest ts-jest` |
+| Node.js (Vite) | Vitest | `npm install -D vitest` |
+| Python | pytest | `pip install pytest` |
+| Go | testing | Built-in |
+| Rust | cargo test | Built-in |
+
+**3. Create config if needed:**
+- Jest: `jest.config.js` with ts-jest preset
+- Vitest: `vitest.config.ts` with test globals
+- pytest: `pytest.ini` or `pyproject.toml` section
+
+**4. Verify setup:**
+```bash
+# Run empty test suite - should pass with 0 tests
+npm test  # Node
+pytest    # Python
+go test ./...  # Go
+cargo test    # Rust
+```
+
+**5. Create first test file:**
+Follow project conventions for test location:
+- `*.test.ts` / `*.spec.ts` next to source
+- `__tests__/` directory
+- `tests/` directory at root
+</framework_setup>
+
+<error_handling>
+## Error Handling
+
+**Test doesn't fail in RED phase:**
+- Feature may already exist - investigate
+- Test may be wrong (not testing what you think)
+- Fix before proceeding
+
+**Test doesn't pass in GREEN phase:**
+- Debug implementation
+- Don't skip to next task
+- Keep iterating until green
+
+**Tests fail in REFACTOR phase:**
+- Undo refactor
+- Commit was premature
+- Refactor in smaller steps
+
+**Unrelated tests break:**
+- Stop and investigate
+- May indicate coupling issue
+- Fix before proceeding
+</error_handling>
+
+<commit_pattern>
+## Commit Pattern for TDD Tasks
+
+Each TDD task produces atomic commits:
+
+```
+test: add failing test for email validation
+
+feat: implement email validation
+
+refactor: extract regex to constant (optional)
+```
+
+This pattern:
+- Creates clean git history
+- Each commit is independently revertable
+- Shows TDD discipline in commit log
+</commit_pattern>
diff --git a/get-shit-done/workflows/execute-phase.md b/get-shit-done/workflows/execute-phase.md
index 2bb0d8100..83e46f8c7 100644
--- a/get-shit-done/workflows/execute-phase.md
+++ b/get-shit-done/workflows/execute-phase.md
@@ -439,6 +439,10 @@ Execute each task in the prompt. **Deviations are normal** - handle them automat
 
    **If `type="auto"`:**
 
+   **Before executing:** Check if task has `tdd="true"` attribute:
+   - If yes: Follow TDD execution flow (see `<tdd_execution>`) - RED → GREEN → REFACTOR cycle with multiple atomic commits
+   - If no: Standard implementation with single commit
+
    - Work toward task completion
    - **If CLI/API returns authentication error:** Handle as authentication gate (see below)
    - **When you discover additional work not in plan:** Apply deviation rules (see below) automatically
@@ -810,6 +814,54 @@ Logged to .planning/ISSUES.md for future consideration:
 
 </deviation_documentation>
 
+<tdd_execution>
+## TDD Task Execution
+
+When executing a task with `tdd="true"` attribute:
+
+**1. Check test infrastructure:**
+If no test framework configured:
+- Detect project type from package.json/requirements.txt/etc.
+- Install minimal test framework (Jest, pytest, Go testing, etc.)
+- Create test config file
+- Verify: run empty test suite
+
+**2. RED - Write failing test:**
+- Read `<test-first>` element for test specification
+- Create test file if doesn't exist (follow project conventions)
+- Write test(s) that describe expected behavior
+- Run tests - MUST fail (if passes, test is wrong or feature exists)
+- Commit: "test: add failing test for [feature]"
+
+**3. GREEN - Implement to pass:**
+- Read `<action>` element for implementation guidance
+- Write minimal code to make test pass
+- Run tests - MUST pass
+- Commit: "feat: implement [feature]"
+
+**4. REFACTOR (if needed):**
+- Clean up code if obvious improvements
+- Run tests - MUST still pass
+- Commit only if changes made: "refactor: clean up [feature]"
+
+**Commit pattern for TDD tasks:**
+Each TDD task produces 2-3 atomic commits:
+1. `test: add failing test for X`
+2. `feat: implement X`
+3. `refactor: clean up X` (optional)
+
+**Error handling:**
+- If test doesn't fail in RED phase: Test is wrong or feature already exists. Investigate before proceeding.
+- If test doesn't pass in GREEN phase: Debug implementation, don't skip to next task.
+- If tests fail in REFACTOR phase: Undo refactor, commit was premature.
+
+**Verification:**
+After TDD task completion, ensure:
+- All tests pass
+- Test coverage for the new behavior exists
+- No unrelated tests broken
+</tdd_execution>
+
 <step name="checkpoint_protocol">
 When encountering `type="checkpoint:*"`:
 
diff --git a/get-shit-done/workflows/plan-phase.md b/get-shit-done/workflows/plan-phase.md
index 9ef016d12..a903f3554 100644
--- a/get-shit-done/workflows/plan-phase.md
+++ b/get-shit-done/workflows/plan-phase.md
@@ -19,8 +19,9 @@ Decimal phases enable urgent work insertion without renumbering:
 2. ~/.claude/get-shit-done/references/plan-format.md
 3. ~/.claude/get-shit-done/references/scope-estimation.md
 4. ~/.claude/get-shit-done/references/checkpoints.md
-5. .planning/ROADMAP.md
-6. .planning/PROJECT.md
+5. ~/.claude/get-shit-done/references/tdd.md
+6. .planning/ROADMAP.md
+7. .planning/PROJECT.md
 
 **Load domain expertise from ROADMAP:**
 - Parse ROADMAP.md's `## Domain Expertise` section for paths
@@ -187,7 +188,33 @@ Decompose phase into tasks. Each task needs:
 - **Verify**: How to prove it worked
 - **Done**: Acceptance criteria
 
-**TDD fit:** Can you write `expect(fn(input)).toBe(output)` before writing `fn`? Yes (business logic, APIs, validation) → test-first. No (UI layout, config, glue code) → standard implementation.
+**TDD detection:** For each task, evaluate TDD fit:
+
+TDD candidates (add `tdd="true"` to task, include `<test-first>` element):
+- Business logic with defined inputs/outputs
+- API endpoints with request/response contracts
+- Data transformations, parsing, formatting
+- Validation rules and constraints
+- Algorithms with testable behavior
+- State machines and workflows
+
+Skip TDD (standard `type="auto"` task):
+- UI layout, styling, visual components
+- Configuration changes
+- Glue code connecting existing components
+- One-off scripts and migrations
+- Simple CRUD with no business logic
+
+**Heuristic:** Can you write `expect(fn(input)).toBe(output)` before writing `fn`?
+→ Yes: Add `tdd="true"`, include `<test-first>` describing the failing test
+→ No: Standard task, no TDD annotation
+
+**Test framework:** If project has no test setup and TDD tasks exist, add a setup task first:
+- Detect project type (package.json → Jest, requirements.txt → pytest, etc.)
+- Add minimal test configuration
+- Create example test file to verify setup
+
+See `~/.claude/get-shit-done/references/tdd.md` for complete TDD guidance.
 
 **Checkpoints:** Visual/functional verification → checkpoint:human-verify. Implementation choices → checkpoint:decision. Manual action (email, 2FA) → checkpoint:human-action (rare).
 
@@ -292,6 +319,21 @@ Phase plan created: .planning/phases/XX-name/{phase}-01-PLAN.md
 - "Set up authentication" / "Make it secure" / "Handle edge cases"
 
 If you can't specify Files + Action + Verify + Done, the task is too vague.
+
+**Good TDD task:**
+```xml
+<task type="auto" tdd="true">
+  <name>Create price calculator with discount rules</name>
+  <files>src/lib/pricing.ts, src/lib/pricing.test.ts</files>
+  <test-first>
+    Test: calculatePrice applies discounts correctly
+    Cases: base 100 + 10% off → 90, base 100 + 20% off + $5 coupon → 75
+  </test-first>
+  <action>Implement calculatePrice(base, discountPercent, couponAmount). Apply percentage first, then flat amount.</action>
+  <verify>npm test -- pricing.test.ts passes</verify>
+  <done>Price calculation handles all discount combinations correctly</done>
+</task>
+```
 </task_quality>
 
 <anti_patterns>