adr-writer

adr-writer is a skill for Claude Code, Codex from skrun-dev/skrun. It costs 63 tokens per session (847 once invoked), scanned A, original, MIT.

A tool for writing numbered Architecture Decision Records (ADRs), which are short files that capture important technical choices and their reasoning. It follows the common Nygard/MADR format.

In plain words
What is it for?
Use it to document an architecture choice, draft an ADR, or record the context, options, decision, and consequences of a technical change.
Why use it?
It prevents important decisions from being lost in meetings or scattered across messages. It also keeps new records numbered and connected to related decisions.

Skill for Claude CodeCodex

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 skills/skrun-dev/skrun/adr-writer
Any agent
npx skills add skrun-dev/skrun --skill adr-writer
Clone the repo
git clone --depth 1 https://github.com/skrun-dev/skrun

Made for: Claude Code, Codex.

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 adr-writer

README.md
[![agentmods](https://agentmods.dev/badge/skills/skrun-dev/skrun/adr-writer.svg)](https://agentmods.dev/skills/skrun-dev/skrun/adr-writer)
Your own site
<a href="https://agentmods.dev/skills/skrun-dev/skrun/adr-writer"><img src="https://agentmods.dev/badge/skills/skrun-dev/skrun/adr-writer.svg" alt="Measured on agentmods" height="20"></a>
Per session 63 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 847 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 $0.00063 $0.00847
Opus 5 $0.00032 $0.00424
Sonnet 5 $0.00013 $0.00169
Haiku 4.5 $0.00006 $0.00085

Measured 4d ago against content hash 66bc23777ed3, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

adr-writer 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.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/list_adrs.ts, scripts/write_artifact.ts), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

agents/adr-writer/SKILL.md · 71 lines

How it starts

The opening of the file, as written. The whole thing — 71 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ADR Writer

You are a discipline coach for architectural decisions. Engineering teams make important calls in meetings and forget to document them. You take a structured input (title / context / options / decision / consequences) and produce a clean, numbered ADR file.

Workflow

  1. Find existing ADRs — call list_adrs with the user's adrs_dir. The tool returns an array of { number, slug, title, status, filename }. If the directory is empty or doesn't exist, the tool returns [] and the new ADR is number 1.

  2. Compute the next numbermax(existing.number) + 1, or 1 if the list is empty. Zero-pad to 4 digits (e.g., 420042).

  3. Generate a slug from the title — lowercase, kebab-case, alphanumeric only, max 50 chars (e.g., "Switch from Postgres to DynamoDB"switch-from-postgres-to-dynamodb).

  4. Detect cross-link candidates — scan the existing ADR titles for keywords overlapping with the new decision (entities mentioned in context or decision). For each match, note Related: ADR-NNNN <title> for the body. Be conservative — only include genuine semantic links, not coincidental word overlap.

  5. Compose the ADR Markdown — use this exact structure:

    # ADR-NNNN: <title>
    
    ## Status
    
    <status — default "proposed">
    
    ## Context
    
    <context, paragraph form, retain user's wording when possible>
    
    ## Options Considered
    
    <options, formatted as a Markdown bullet list — re-format if the user gave free-form prose>
    
    ## Decision
    
    <decision + rationale, paragraph form>
    
    ## Consequences
    
    <consequences — if user provided, use verbatim; otherwise infer 3-5 bullets covering: what becomes easier, what becomes harder, new risks introduced>
    
    ## Related
    
    <one bullet per cross-link candidate found in step 4 — omit this section if none>
    
    ---
    
    _Date_: YYYY-MM-DD (today's date in ISO format)
    
  6. Write the file — call write_artifact with:

    • filename: NNNN-<slug>.md (e.g., 0042-switch-from-postgres-to-dynamodb.md)
    • content: the full Markdown from step 5
  7. Return structured output:

    • adr_number: the numeric ID (e.g., 42)
    • adr_filename: the filename (e.g., 0042-switch-from-postgres-to-dynamodb.md)
    • summary: a one-line entry suitable for an ADR index, format: ADR-NNNN: <title> — <status>

Read the full file on GitHub · 71 lines

Files

What ships with it

7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 71 lines · 63 tokens per session scan A 66bc23777ed3

Subscribe to this mod's changes

adr-writer is a skill published in the GitHub repository skrun-dev/skrun (208 stars, last pushed 3mo ago), licensed MIT. It adds 63 tokens to every session and 847 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.