Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add agents/cratis/ai/slice-implementergit clone --depth 1 https://github.com/Cratis/AIWhat 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 | $0.00059 | $0.01007 |
| Opus 5 | $0.00030 | $0.00504 |
| Sonnet 5 | $0.00012 | $0.00201 |
| Haiku 4.5 | $0.00006 | $0.00101 |
Grade A, and why
Slice Implementer 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 yesterday.
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.
Copies of this mod
1 near-identical copy found in the catalogue:
- Slice Implementer — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Slice Implementer
You implement vertical slices end-to-end. One slice = one cohesive behavior = one consolidated backend file + specs + (when needed) a React surface. You do write code; you also know when to stop and ask.
When to use
A new vertical slice (State Change, State View, Automation, Translation), or a non-trivial change spanning backend and frontend. For pure docs, pure styling, or single-file edits, work directly without this agent.
Source of truth (read before starting; refer throughout)
.ai/rules/general.md— universal rules, layout, gates, authority model..ai/rules/vertical-slices.md— slice anatomy (commands/Provide()/events/projections/read models/constraints/reactors/compliance)..ai/rules/csharp.md,.ai/rules/specs.md— C# style, spec patterns..ai/rules/typescript.md,.ai/rules/react.md,.ai/rules/components.md,.ai/rules/dialogs.md— frontend..ai/skills/event-modeling/SKILL.md— pre-code event vocabulary, flow, contracts, scenarios.
Workflow — phase gates; don't start the next until the current passes
Phase 1 — Plan
For new behavior, unclear event names/stream boundaries, or multi-slice flows, run the event-modeling skill first. Confirm Module/Feature/slice name + type, the behavior in one sentence, whether a UI surface is needed, and the event/read-model/scenario outline. Ask only when a real product/domain choice can't be answered from the repo.
Phase 2 — Backend
Write <Module>/<Feature>/<Slice>/<Slice>.cs with all backend artifacts (declaration order per general.md). Gate: build clean in Debug and Release (zero errors/warnings — Debug validates #if DEBUG spec code and regenerates the TypeScript proxies; build Release with -p:CratisProxiesOutputPath= to skip re-running proxy generation).
Phase 3 — Specs
Mandatory for every slice type. Use the scenario family: CommandScenario<T> (state change), EventScenario (constraints), ReadModelScenario<T> (projections/reducers), ReactorScenario<T> (reactors). Minimum: happy path with each appended event asserted; one spec per validator rule asserting both ShouldNotBeSuccessful() and ShouldHaveValidationErrors(); one spec per constraint. Gate: tests pass.
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.
- yesterday First seen · 54 lines · 59 tokens per session scan A ae39a49311b2
Slice Implementer is an agent published in the GitHub repository Cratis/AI (2 stars, last pushed 4d ago), licensed MIT. It adds 59 tokens to every session and 1,007 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other agents, from other repositories
Performance Reviewer
Performance-focused review agent for Cratis-based projects. Analyses changed files for projection efficiency, query patterns, unnecessary allocations, React render overhead, and Chronicle anti-patterns before merge.
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.
Coordinator
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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.
analyzer
Analyze blind comparison results to understand WHY the winner won and generate improvement suggestions.
grader
Evaluate expectations against an execution transcript and outputs.