task-implementor.md
June 25, 2026 Β· View on GitHub
The Task Implementor custom agent transforms planning files into working code. It executes plans task by task, tracks all changes, and supports stop controls for review between phases.
When to Use Task Implementor
Use Task Implementor after completing planning when you need:
- β‘ Precise execution following the plan exactly
- π Change tracking documenting all modifications
- βΈοΈ Stop controls for review between phases
- β Verification that success criteria are met
What Task Implementor Does
- Reads the plan phase by phase, task by task
- Loads only needed details using line ranges
- Implements code following workspace conventions
- Tracks changes in a changes log
- Verifies success criteria before marking complete
- Pauses at stop points for your review
Note
Why the constraint matters: Task Implementor has one job: execute the plan using patterns documented in research. No time wasted rediscovering conventions, no "creative" decisions that break existing patterns. Just verified facts applied methodically.
Output Artifacts
Task Implementor creates working code and a changes log:
.copilot-tracking/
βββ changes/
βββ {{YYYY-MM-DD}}-<topic>-changes.md # Log of all changes made
Plus all the actual code files created or modified during implementation.
How to Use Task Implementor
Step 1: Clear Context and Open the Plan
π΄ Start with /clear or a new chat after Task Planner completes.
After clearing, open your plan file (.copilot-tracking/plans/<topic>-plan.instructions.md) in the editor before invoking Task Implementor. This ensures the agent can locate and follow the plan without relying on chat history.
Tip
Context management is an engineering practice, not a ritual. Clearing context removes accumulated tokens that cause the model to ignore its instructions. See Context Engineering for the full explanation.
Step 2: Select the Custom Agent
- Open GitHub Copilot Chat (
Ctrl+Alt+I) - Click the agent picker dropdown
- Select Task Implementor
Step 3: Reference Your Plan
Use /task-implement or /rpi-implement to start execution. The prompt automatically locates the plan and switches to Task Implementor. Alternatively, provide the path to your plan file directly.
Step 4: Set Stop Controls
Choose your review cadence:
phaseStop=true(default): Pause after each phasetaskStop=true: Pause after each task- Both false: Run to completion
Step 5: Review and Continue
At each stop point:
- Review the changes made
- Verify code compiles and lints
- Approve or request adjustments
- Continue to next phase/task
Example Prompt
/task-implement
Or reference a specific generated prompt:
/implement-blob-storage
Understanding Stop Controls
Phase Stop (Default: true)
Pauses after completing all tasks in a phase:
Phase 1: [x] Task 1.1, [x] Task 1.2 β STOP for review
Phase 2: [ ] Task 2.1, [ ] Task 2.2
Task Stop (Default: false)
Pauses after each individual task:
Phase 1: [x] Task 1.1 β STOP
[ ] Task 1.2
Tips for Better Implementation
β Do:
- Review changes at each stop point
- Run linters and validators
- Check that success criteria are met
- Ask for adjustments before continuing
β Don't:
- Skip reviewing changes
- Ignore failing tests or lints
- Rush through all phases without checking
The Changes Log
Task Implementor maintains a changes log with sections:
## Changes
### Added
* src/storage/blob_client.py - Azure Blob Storage client class
### Modified
* src/pipeline/config.py - Added blob storage configuration
### Removed
* (none this implementation)
At Completion
When all phases are complete, Task Implementor provides:
- Summary of all changes from the changes log
- Links to planning files for reference
- Recommendation to proceed to review
Common Pitfalls
| Pitfall | Solution |
|---|---|
| Plan not found | Complete Task Planner first |
| Skipping reviews | Use phaseStop=true for important changes |
| Not running validations | Check lint/test after each phase |
| Context issues | Use /clear before starting; see Context Engineering |
Next Steps
After Task Implementor completes:
- Clear context using
/clearor starting a new chat - Review using
/task-reviewto switch to Task Reviewer - Address findings from the review before committing
- Commit your changes with a descriptive message
- Clean up planning files if no longer needed
Tip
Use the β Review handoff button when available to transition directly to Task Reviewer with context.
For your next task, you can start the RPI workflow again with Task Researcher.
π€ Crafted with precision by β¨Copilot following brilliant human instruction, then carefully refined by our team of discerning human reviewers.