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 skills/helderberto/agent-skills/plannpx skills add helderberto/agent-skills --skill plangit clone --depth 1 https://github.com/helderberto/agent-skillsWhat 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 | $0.00065 | $0.01389 |
| Opus 5 | $0.00032 | $0.00694 |
| Sonnet 5 | $0.00013 | $0.00278 |
| Haiku 4.5 | $0.00006 | $0.00139 |
Grade A, and why
plan 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.
How it starts
The opening of the file, as written. The whole thing — 168 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Plan
Break a spec into phased vertical slices (tracer bullets).
Interactive prompts: present options as a numbered list and wait for the user's choice.
Output: .specs/plans/<slug>.md.
Input
The argument (if provided) is: $ARGUMENTS
Use argument as <slug>. If empty, list specs as numbered options and wait for the user's choice.
Workflow
1. Read the spec
Read .specs/specs/<slug>.md. If missing, list specs as numbered options and wait for the user's choice.
If .specs/plans/<slug>.md exists, present options and wait:
- Overwrite existing (Recommended)
- Pick a new name
2. Explore the codebase
Map architecture, patterns, integration points. Skip if codebase context exists from prior step.
Research protocol: codebase first, then docs. Unverifiable claims → flag as uncertain, never fabricate.
3. Identify durable architectural decisions
Before slicing, extract decisions that hold across all phases:
- Route structures / URL patterns
- Database schema shape
- Key data models and definitions
- Auth/authorization approach
- Third-party service boundaries
4. Draft vertical slices
Each phase: thin vertical slice through all layers (schema → service → API → UI → tests). Demoable alone.
Deriving tasks from the spec:
| Spec Section | Becomes |
|---|---|
| New Modules | Implement module with interface |
| Schema Changes | Migration + validation |
| API Contracts | Route returning shape |
| Navigation | Wire component to route |
| User Stories | Verify coverage; add task if missing |
| Testing Decisions | Tests land in the phase where their module lands |
| Out of Scope | Never create tasks for these |
Within each slice, order by dependency: schema → service → API → UI → tests. Happy paths before edge cases.
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 · 168 lines · 65 tokens per session scan A a5b19215df11
plan is a skill published in the GitHub repository helderberto/agent-skills (13 stars, last pushed 10d ago), licensed MIT. It adds 65 tokens to every session and 1,389 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 2026-08-30.
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api-and-interface-design
Guides stable API and interface design. Use when designing APIs, module boundaries, or any public interface. Use when creating REST or GraphQL endpoints, defining type contracts between modules, or establishing boundaries between frontend and backend.
doubt-driven-development
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test-driven-development
Drives development with tests. Use when implementing any logic, fixing any bug, or changing any behavior. Use when you need to prove that code works, when a bug report arrives, or when you're about to modify existing functionality.