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 commands/jimmc414/claude-code-plugin-marketplace/collaborative-spec-builder-existinggit clone --depth 1 https://github.com/jimmc414/claude-code-plugin-marketplaceWrote 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/commands/jimmc414/claude-code-plugin-marketplace/collaborative-spec-builder-existing)<a href="https://agentmods.dev/commands/jimmc414/claude-code-plugin-marketplace/collaborative-spec-builder-existing"><img src="https://agentmods.dev/badge/commands/jimmc414/claude-code-plugin-marketplace/collaborative-spec-builder-existing.svg" alt="Measured on agentmods" 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 | $0.00013 | $0.01228 |
| Opus 5 | $0.00006 | $0.00614 |
| Sonnet 5 | $0.00003 | $0.00246 |
| Haiku 4.5 | $0.00001 | $0.00123 |
Grade A, and why
collaborative-spec-builder-existing 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 6d 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.
How it starts
The opening of the file, as written. The whole thing — 157 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Collaborative Specification Builder (Existing Project)
You are entering a collaborative specification building session for an existing project or feature. This process will:
- Define an aspirational specification - what the code SHOULD do
- Analyze the current implementation against that spec
- Identify gaps and create actionable tasks to close them
Important Distinction
Throughout this process, distinguish between:
- Current behavior: What the code actually does today
- Aspirational behavior: What it should do according to the spec
When discussing behavior, be explicit: "Currently it does X, but the spec requires Y."
Specification Areas to Cover
Systematically gather information across these areas:
Intent
- What problem does this solve? Why does it need to exist?
- What is the broader context? What goals guide decisions?
- What is explicitly out of scope? How will this be used?
Domain Types / Vocabulary
- What are the core types involved?
- What do key terms mean precisely?
Input Contract
- What inputs should be accepted? Types, formats, valid ranges?
Output Contract
- What should be returned? Shape/type of output?
Preconditions
- What must be true before execution?
- What should be validated vs. assumed?
Postconditions
- What should be guaranteed after successful execution?
Invariants
- What must remain true throughout execution?
Constraints
- What rules should govern valid behavior? What should be prohibited?
State Transitions
- What states can entities be in? What transitions should be legal?
Side Effects
- What external state should be modified? What I/O should occur?
Error Cases
- What can fail? How should each failure be handled?
Boundary Conditions
- Empty inputs, nulls, zeros, max values - what should happen?
Assumptions
- What should be assumed true but not explicitly checked?
Dependencies / Environment (if relevant)
- Required libraries, services, runtime, configuration?
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.
- 6d ago First seen · 157 lines · 13 tokens per session scan A 55bd4d6e3745
collaborative-spec-builder-existing is a command published in the GitHub repository jimmc414/claude-code-plugin-marketplace (4 stars, last pushed yesterday), licensed MIT. It adds 13 tokens to every session and 1,228 once invoked, about $0.0001 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 commands, from other repositories
checklist
Generate a custom checklist for the current feature based on user requirements.
clarify
Identify underspecified areas in the current feature spec by asking up to 5 highly targeted clarification questions and encoding answers back into the spec.
specify
Create or update the feature specification from a natural language feature description.
analyze
Perform a non-destructive cross-artifact consistency and quality analysis across spec.md, plan.md, and tasks.md after task generation.
constitution
Create or update the project constitution from interactive or provided principle inputs.
converge
Assess the current codebase against the feature's spec, plan, and tasks, then append any remaining unbuilt work as new tasks to tasks.md so implement can complete it.