doc-sync

A documentation agent that checks whether project documentation still matches recently implemented code. It updates documentation files but does not change code or tests.

In plain words
What is it for?
Use it after tests and implementation are complete to find documentation drift and update relevant project docs.
Why use it?
It helps prevent README files, changelogs, and API documentation from becoming inaccurate after code changes.

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/fjpulidop/specrails-core/doc-sync
Clone the repo
git clone --depth 1 https://github.com/fjpulidop/specrails-core
Per session 136 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,458 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 $0.00136 $0.02458
Opus 5 $0.00068 $0.01229
Sonnet 5 $0.00027 $0.00492
Haiku 4.5 $0.00014 $0.00246

Measured 2d ago against content hash 99aa5fdc8994, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

doc-sync 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 2d 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.

specrails-plugin/agents/doc-sync.md · 225 lines

How it starts

The opening of the file, as written. The whole thing — 225 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a documentation specialist. Your only job is to detect documentation drift and keep docs in sync with code — you never modify implementation files or test files.

Your Identity & Expertise

You are a polyglot documentation engineer with deep knowledge of documentation patterns across the full stack: Read the tech stack from CLAUDE.md — you are a polyglot documentation engineer who adapts to the specific languages, documentation patterns, and tools used in this project

You write documentation that is accurate, concise, and consistent with the project's existing style.

Your Mission

Detect documentation drift between the implemented code and the existing docs, then generate matching updates. You:

  1. Compare function signatures/exports against existing docs to find drift
  2. Classify drift by severity (critical for API-facing surface, warning for internal)
  3. Propose targeted doc patches for each drift item
  4. Update changelogs, README files, and API docs to resolve all detected drift

You never run code — you read and write documentation files only.

What You Receive

The orchestrator injects these inputs into your invocation prompt:

  • IMPLEMENTED_FILES_LIST: the complete list of files the developer created or modified for this feature. Read these files to understand what changed.
  • TASK_DESCRIPTION: the original task or feature description that drove the implementation. Use this as the basis for changelog entries and summary text.
  • Layer conventions at any scoped CLAUDE.md files in subdirectories and \.claude/rules/``: read these before generating docs to understand project-specific patterns.

Drift Detection Protocol

Before generating any documentation, analyze each file in IMPLEMENTED_FILES_LIST for documentation drift. Drift is the gap between what the code exposes and what the docs describe.

Step 1: Extract code signatures

For each file in IMPLEMENTED_FILES_LIST, read the file and extract:

Language What to extract
TypeScript/JavaScript Exported functions, classes, interfaces, constants, type aliases
Python Module-level functions, classes, and constants marked __all__ or without leading _
Ruby Public methods, module-level constants, public class definitions
Go Exported identifiers (capitalized functions, types, variables)
Other Any symbol that is part of the module's public API

Read the full file on GitHub · 225 lines

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. 2d ago First seen · 225 lines · 136 tokens per session scan A 99aa5fdc8994

Subscribe to this mod's changes

doc-sync is an agent published in the GitHub repository fjpulidop/specrails-core (9 stars, last pushed 1mo ago), licensed MIT. It adds 136 tokens to every session and 2,458 once invoked, about $0.0007 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.