keystone: Command for Claude Code

.claude/commands/keystone-spec.md

keystone-spec is a command for Claude Code from tacoda/keystone. It costs 11 tokens per session (315 once invoked), scanned A, a copy of spec, MIT.

A specification command for turning a task description into a written intent, acceptance criteria, non-goals, and open questions.

In plain words
What is it for?
Use it at the start of work to capture a tracker card, conversation, or TODO entry as a project specification.
Why use it?
It replaces vague requests with conditions that a reviewer can check objectively.

Command for Claude Code

Written for Claude Code: installed under .claude/.

This is tacoda/keystone's own configuration. It tells Claude Code how to work on keystone itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything keystone configures →

Reuse

Borrowing it

Nothing to install: this file belongs to tacoda/keystone. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/tacoda/keystone/main/.claude/commands/keystone-spec.md
Clone the repo
git clone --depth 1 https://github.com/tacoda/keystone

Made for: Claude Code.

Wrote 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.

agentmods badge for keystone-spec

README.md
[![agentmods](https://agentmods.dev/badge/commands/tacoda/keystone/keystone-spec.svg)](https://agentmods.dev/commands/tacoda/keystone/keystone-spec)
Your own site
<a href="https://agentmods.dev/commands/tacoda/keystone/keystone-spec"><img src="https://agentmods.dev/badge/commands/tacoda/keystone/keystone-spec.svg" alt="Measured on agentmods" height="20"></a>
Per session 11 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 315 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 97% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00011 $0.00315
Opus 5 $0.00005 $0.00158
Sonnet 5 $0.00002 $0.00063
Haiku 4.5 $0.00001 $0.00032

Measured 3d ago against content hash 980aced0028f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

keystone-spec 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 3d 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.

Origin

This is a copy

97% identical to spec — 4 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.

.claude/commands/keystone-spec.md · 31 lines

What it actually says

spec

Capture intent and acceptance criteria for a unit of work. First action on any task. Read .charter/guides/process/spec.md for the full discipline.

Inputs

  • A tracker card ID (Jira / Linear / GitHub Issues / Asana), or
  • A conversation describing the work, or
  • A TODO.md entry.

If a tracker card was named, fetch its description via whatever tooling the agent has (MCP server, gh issue view, jira CLI, web fetch). Copy any acceptance criteria into the spec.

Activities

  1. Restate the intent in your own words.
  2. List acceptance criteria — explicit, testable bullets a reviewer can verify objectively.
  3. List non-goals — what is not in scope, to prevent feature creep.
  4. Flag uncertainty — open questions the user must answer before planning.
  5. Save the spec to docs/specs/YYYY-MM-DD-<topic>.md with the frontmatter shape described in .charter/guides/process/spec.md (if the project has that location; otherwise capture inline in the chat).

Gate

Do not proceed to planning until the user has explicitly accepted the spec.

Iron law

No proceeding without explicit acceptance criteria. A spec that says "make X better" is not yet a spec.

Changes

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.

  1. 3d ago First seen · 31 lines · 11 tokens per session scan A 980aced0028f

Subscribe to this mod's changes

keystone-spec is a command published in the GitHub repository tacoda/keystone (44 stars, last pushed 2mo ago), licensed MIT. It adds 11 tokens to every session and 315 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 97% identical to spec, differing in 4 lines, and is treated as a copy.