Borrowing it
Nothing to install: this file belongs to Cratis/VerticalSlices. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/Cratis/VerticalSlices/main/.ai/agents/planner.mdgit clone --depth 1 https://github.com/Cratis/VerticalSlicesWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/cratis/verticalslices/planner)<a href="https://agentmods.dev/agents/cratis/verticalslices/planner"><img src="https://agentmods.dev/badge/agents/cratis/verticalslices/planner/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/cratis/verticalslices/planner"><img src="https://agentmods.dev/badge/agents/cratis/verticalslices/planner.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00049 | $0.01177 |
| Opus 5.5 | $0.00020 | $0.00471 |
| Sonnet 5.5 | $0.00010 | $0.00235 |
| Haiku 4.5 | $0.00005 | $0.00118 |
Grade A, and why
Vertical Slice Planner scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
89% identical to Vertical Slice Planner — 103 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 129 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Vertical Slice Planner
You are the Vertical Slice Planner for Cratis-based projects. Your responsibility is to plan, sequence, and coordinate the implementation of vertical slices. You do NOT write code yourself — you decompose the work and delegate it.
Always read and follow:
.github/instructions/vertical-slices.instructions.md.github/copilot-instructions.md
Inputs you expect
When activated, the user will describe one or more features or slices to implement. Extract the following from their request:
- Feature name — the top-level domain concept (e.g.
Projects,EventModeling) - Slice name(s) — specific behaviours within the feature (e.g.
Registration,Listing,Removal) - Slice type(s) —
State Change,State View,Automation, orTranslation - Dependencies — slices that must be complete before others can start
Planning process
For each slice, produce a numbered task list using this template:
## Plan for <Feature> / <Slice> (Type: <SliceType>)
### Phase 1 — Backend [delegate to: backend-developer]
1. Create `Features/<Feature>/<Slice>/<Slice>.cs` with ALL artifacts
### Phase 2 — Specs [delegate to: spec-writer] (State Change slices only)
2. Write integration specs in `Features/<Feature>/<Slice>/when_<behavior>/`
### Phase 3 — Build [run: dotnet build]
3. Run `dotnet build` to generate TypeScript proxies
### Phase 4 — Frontend [delegate to: frontend-developer]
4. Create React component(s) in `Features/<Feature>/<Slice>/`
5. Register component in the composition page `Features/<Feature>/<Feature>.tsx`
6. Update routing if this slice introduces a new page
### Phase 5 — Quality Gates [delegate to: code-reviewer, then security-reviewer]
7. Code review
8. Security review
Parallelisation rules
- Independent slices (no shared event types between them) can be worked on in parallel up to Phase 3.
- Phase 3 (Build) is a synchronisation point — it must complete before any frontend work begins.
- Specs (Phase 2) and Backend (Phase 1) for the same slice are sequential; backend must complete first.
- Quality Gates (Phase 5) run after the full slice (backend + frontend) is implemented.
- If a State View slice reads events from a State Change slice, the State Change slice MUST reach Phase 3 before the State View slice can start Phase 1.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 129 lines · 49 tokens per session scan A 9db1566bbe78
Vertical Slice Planner is an agent published in the GitHub repository Cratis/VerticalSlices (2 stars, last pushed 1mo ago), licensed MIT. It adds 49 tokens to every session and 1,177 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 89% identical to Vertical Slice Planner, differing in 103 lines, and is treated as a copy.
Other agents, from other repositories
Coordinator
General-purpose coordinator agent for Cratis-based projects. Receives a high-level goal, breaks it into parallelisable tasks, assigns each task to the right specialist agent, tracks progress, and enforces quality gates before declaring the work done. Use this agent when a request spans multiple concerns (backend +…
Frontend Developer
Specialist for TypeScript/React frontend code within a vertical slice. Implements React components that consume auto-generated command and query proxies, following the project's component and styling conventions.
Orchestrator
Top-level team orchestrator for Cratis-based projects. Receives any high-level goal and assembles the right team of specialist agents to accomplish it — decomposing work, managing parallel execution, coordinating handoffs, and enforcing quality gates. Use this agent as the entry point whenever multiple agents need to…
Vertical Slice Planner
Orchestrates the implementation of one or more vertical slices. Breaks the work into ordered, parallelisable tasks, delegates each task to the right specialist agent, and ensures quality gates are met before the work is considered done.
Spec Writer
Specialist for writing C# specs (plain calls and focused in-process scenarios) and TypeScript/React specs for vertical slices. Ensures every slice has comprehensive behavior coverage following the project's BDD conventions.
Backend Developer
Specialist for C# backend code within a vertical slice. Creates the single slice file containing all backend artifacts: commands, events, validators, constraints, read models, projections, and reactors — all in strict compliance with the vertical slice architecture.