SLASH COMMANDFree BlueprintLicense: MIT
Slash Command: /gan-build
Slash Command: /gan-build is a verified SLASH_COMMAND blueprint on Promptally in Interactive Slash Commands optimized for leading AI models. Run a generator/evaluator build loop for implementation tasks with bounded iterations and scoring. Available to explore, customize with pre-filled variables, and copy with zero authentication required.
Created by @promptallyTechnical Specifications
| Specification | Value |
|---|---|
| Artifact type | SLASH COMMAND (Interactive Slash Commands) |
| Compatible engines | Universal / Model Agnostic |
| Input variables | None (pre-filled) |
| Approximate tokens | 778 |
| Source file | gan-build.md |
| Access tier | Free public (MIT) |
Pre-Filled Template
gan-build.md
Parse the following from $ARGUMENTS:
1. `brief` — the user's one-line description of what to build
2. `--max-iterations N` — (optional, default 15) maximum generator-evaluator cycles
3. `--pass-threshold N` — (optional, default 7.0) weighted score to pass
4. `--skip-planner` — (optional) skip planner, assume spec.md already exists
5. `--eval-mode MODE` — (optional, default "playwright") one of: playwright, screenshot, code-only
## GAN-Style Harness Build
This command orchestrates a three-agent build loop inspired by Anthropic's March 2026 harness design paper.
### Phase 0: Setup
1. Create `gan-harness/` directory in project root
2. Create subdirectories: `gan-harness/feedback/`, `gan-harness/screenshots/`
3. Initialize git if not already initialized
4. Log start time and configuration
### Phase 1: Planning (Planner Agent)
Unless `--skip-planner` is set:
1. Launch the `gan-planner` agent via Task tool with the user's brief
2. Wait for it to produce `gan-harness/spec.md` and `gan-harness/eval-rubric.md`
3. Display the spec summary to the user
4. Proceed to Phase 2
### Phase 2: Generator-Evaluator Loop
```
iteration = 1
while iteration <= max_iterations:
# GENERATE
Launch gan-generator agent via Task tool:
- Read spec.md
- If iteration > 1: read feedback/feedback-{iteration-1}.md
- Build/improve the application
- Ensure dev server is running
- Commit changes
# Wait for generator to finish
# EVALUATE
Launch gan-evaluator agent via Task tool:
- Read eval-rubric.md and spec.md
- Test the live application (mode: playwright/screenshot/code-only)
- Score against rubric
- Write feedback to feedback/feedback-{iteration}.md
# Wait for evaluator to finish
# CHECK SCORE
Read feedback/feedback-{iteration}.md
Extract weighted total score
if score >= pass_threshold:
Log "PASSED at iteration {iteration} with score {score}"
Break
if iteration >= 3 and score has not improved in last 2 iterations:
Log "PLATEAU detected — stopping early"
Break
iteration += 1
```
### Phase 3: Summary
1. Read all feedback files
2. Display final scores and iteration history
3. Show score progression: `iteration 1: 4.2 → iteration 2: 5.8 → ... → iteration N: 7.5`
4. List any remaining issues from the final evaluation
5. Report total time and estimated cost
### Output
```markdown
## GAN Harness Build Report
**Brief:** [original prompt]
**Result:** PASS/FAIL
**Iterations:** N / max
**Final Score:** X.X / 10
### Score Progression
| Iter | Design | Originality | Craft | Functionality | Total |
|------|--------|-------------|-------|---------------|-------|
| 1 | ... | ... | ... | ... | X.X |
| 2 | ... | ... | ... | ... | X.X |
| N | ... | ... | ... | ... | X.X |
### Remaining Issues
- [Any issues from final evaluation]
### Files Created
- gan-harness/spec.md
- gan-harness/eval-rubric.md
- gan-harness/feedback/feedback-001.md through feedback-NNN.md
- gan-harness/generator-state.md
- gan-harness/build-report.md
```
Write the full report to `gan-harness/build-report.md`.How to use this slash command
- Review the pre-filled example and source files above.
- Copy the template or download
gan-build.md, then use it in your model, IDE, or workflow tool. - Compare your result with the sample output when one is provided.
Frequently Asked Questions
How do I use Slash Command: /gan-build?
Open the slash command on Promptally, review the pre-filled example, then copy the template or download gan-build.md and paste it into your model, IDE or workflow tool. Slash Command: /gan-build is a static blueprint with no dynamic variables. Copy it and use it as-is.
Is Slash Command: /gan-build free?
Yes. Slash Command: /gan-build is free to view, copy and download on Promptally without creating an account. It is published under the MIT license.
What variables does Slash Command: /gan-build need?
Slash Command: /gan-build is a static blueprint with no dynamic variables. Copy it and use it as-is.