spec-designer

spec-designer is an agent for coding agents from permit0-ai/permit0. It costs 0 tokens per session (184 once invoked), scanned A, original, Apache-2.0.

An automated coding agent that turns a GitHub issue into a short implementation specification.

In plain words
What is it for?
Use it to write a specification with the problem, approach, files to change, test cases and commands, and acceptance checklist.
Why use it?
It gives developers a clear plan before coding, including affected files, tests, and conditions for accepting the change.

Agent

Install

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.

agentmods
npx agentmods add agents/permit0-ai/permit0/spec-designer
Clone the repo
git clone --depth 1 https://github.com/permit0-ai/permit0

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 spec-designer

README.md
[![agentmods](https://agentmods.dev/badge/agents/permit0-ai/permit0/spec-designer.svg)](https://agentmods.dev/agents/permit0-ai/permit0/spec-designer)
Your own site
<a href="https://agentmods.dev/agents/permit0-ai/permit0/spec-designer"><img src="https://agentmods.dev/badge/agents/permit0-ai/permit0/spec-designer.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 184 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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 $0.00000 $0.00184
Opus 5 $0.00000 $0.00092
Sonnet 5 $0.00000 $0.00037
Haiku 4.5 $0.00000 $0.00018

Measured 4d ago against content hash 6cb0566c7d6d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

spec-designer 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 4d 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.

.github/agents/spec-designer.md · 15 lines

What it actually says

You are the spec-design agent in the Polis automated pipeline.

Given a GitHub issue, produce a concise, implementable specification. Write the spec to the file path you are told, creating parent directories. Structure:

  • Problem — restate what the issue asks, in your own words

  • Approach — the chosen implementation approach (1-3 paragraphs)

  • Affected files — bullet list of files to create/modify

  • Test plan — enumerated, checkable test cases (one bullet each) that map 1:1 to the

    acceptance criteria, AND the exact command used to run them (e.g. pytest -q, cargo test, go test ./...). This command is authoritative for scripts/test.sh.
  • Acceptance criteria — a checklist a reviewer can verify

Be specific and minimal. Do not write implementation code. Apply YAGNI.

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. 4d ago First seen · 15 lines · 0 tokens per session scan A 6cb0566c7d6d

Subscribe to this mod's changes

spec-designer is an agent published in the GitHub repository permit0-ai/permit0 (185 stars, last pushed 2mo ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 184 tokens. 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.