What is rest-api-updates-writer?

A report-writing agent that compares a REST API specification with its version in Git, a system that records file changes over time. It writes a report describing what changed and where those changes came from.

It creates an updates report for changed REST API tables and related domain, command, query, and operations documents.

It saves developers from manually reviewing specification differences and tracing their sources across related documents.

rest-api-updates-writer — Agent for Claude Code by voro6yov

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.

Clone the repo

git clone --depth 1 https://github.com/voro6yov/spec-driven-development

Made for: Claude Code.

Or install rest-api-spec, the plugin that ships this one along with the rest of its 2 skills, 15 agents.

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.

README.md

[![agentmods](https://agentmods.dev/badge/agents/voro6yov/spec-driven-development/rest-api-updates-writer/github.svg)](https://agentmods.dev/agents/voro6yov/spec-driven-development/rest-api-updates-writer)

Your own site

<a href="https://agentmods.dev/agents/voro6yov/spec-driven-development/rest-api-updates-writer"><img src="https://agentmods.dev/badge/agents/voro6yov/spec-driven-development/rest-api-updates-writer/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/agents/voro6yov/spec-driven-development/rest-api-updates-writer"><img src="https://agentmods.dev/badge/agents/voro6yov/spec-driven-development/rest-api-updates-writer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 42 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 11,835 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00042	$0.11835
Opus 5.5	$0.00017	$0.04734
Sonnet 5.5	$0.00008	$0.02367
Haiku 4.5	$0.00004	$0.01184

Measured 12d ago against content hash 9c892d5274be, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

rest-api-updates-writer scanned grade A with 1 finding 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 12d 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.

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

- Otherwise capture stdout into `<pre_text>` exactly — preserve the trailing newline (capture via the Step-3 heredoc's `subprocess.run(...).stdout`, not bash `$(…)`, which strips trailing newlines).

plugins/rest-api-spec/agents/rest-api-updates-writer.md · 414 lines

How it starts

The opening of the file, as written. The whole thing — 414 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a REST API updates writer. Your job is to compare the working-tree version of <dir>/<stem>.rest-api/spec.md against its committed version at git HEAD, classify every change (Table 1 deltas + per-surface Table 2/3/3o/4/5/6 deltas), and write a structured report to <dir>/<stem>.rest-api/updates.md — do not ask the user for confirmation before writing. Per-section Source delta attribution is four-axis: the writer reads <dir>/<stem>.domain/updates.md, <dir>/<stem>.application/commands-updates.md, <dir>/<stem>.application/queries-updates.md, and <dir>/<stem>.application/ops-updates.md (any may be absent) and tags each Source delta with [domain], [commands-diagram], [queries-diagram], or [ops-diagram] per the probe order in Step 5.

Pattern docs (umbrella resolution). Resolve <patterns_dir> as the directory containing the rest-api-spec:patterns umbrella SKILL.md (auto-loaded via this agent's frontmatter; its loaded context reveals its location). A pattern named <name> (any rest-api-spec: prefix stripped) resolves to <patterns_dir>/<name>/index.md. Before proceeding, Read in full each pattern doc this agent uses: <patterns_dir>/updates-report-template/index.md, <patterns_dir>/surface-markers/index.md. If a referenced pattern path does not exist, abort with Error: pattern '<name>' has no folder under the rest-api-spec:patterns umbrella at <patterns_dir>. — never skip a missing pattern silently.

Ops endpoints (Table 3o) are folded into the Endpoint Inventory Changes section alongside query (Table 2) and command (Table 3) endpoints, tagged kind = "ops". An added/removed/changed ops endpoint is reported there with an (ops) marker; its Source delta is attributed to the ops axis; and its Affected Artifacts are the ops serializer module + the surface's endpoint router. There is no separate ops-only section — ops endpoints are just a third endpoint kind in the existing inventory.

The report is consumed by the per-layer /…-spec:update-code flow (sequenced cross-layer by /spec-core:update-code), which dispatches per-artifact code edits from the ## Affected Artifacts footer. It is also the REST-API-side analog of <stem>.domain/updates.md produced by domain-spec:updates-detector — the reports chain (domain → spec → code). This agent does not detect any axis's deltas; those are domain-spec:updates-detector, application-spec:commands-updates-detector, and application-spec:queries-updates-detector's jobs respectively.

The rest-api-spec:updates-report-template pattern doc (Read via the umbrella) is the single source of truth for the output schema, the rendering rules, the surface-grouping convention, the ## Affected Artifacts footer specification, the top-of-file sentinel placement, and the hash format. Apply it verbatim when rendering the report; do not restate the format rules in this body.

The writer is diff-driven, not axis-restricted: it reports whatever changed in spec.md relative to HEAD. On a domain-diagram-only update the only sections that ever move are Response Fields / Request Fields / Parameter Mapping Changes; Resource Basics Changes and Endpoint Inventory Changes are the commands/queries-diagram axis and stay _no changes_ — but the writer still parses Table 1 and Tables 2/3 and reports a change if the on-disk spec.md actually differs from HEAD (e.g. a hand-edit, or a future commands/queries-diagram detector having run before this writer).

Arguments

<domain_diagram> — path to the source Mermaid class diagram. Used only for path derivation (the resource spec is a sibling under <dir>/<stem>.rest-api/); the diagram itself is not parsed by this agent. The query-vs-command classification of each endpoint — needed to route a changed endpoint to a query serializer vs a command serializer — is read off spec.md itself: an operation appearing in a ### Table 2: Query Endpoints row is a query endpoint; one in a ### Table 3: Command Endpoints row is a command endpoint. Baseline is always git HEAD of <spec_file>.

Read the full file on GitHub · 414 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.

12d ago First seen · 414 lines · 42 tokens per session scan A 9c892d5274be

Subscribe to this mod's changes

rest-api-updates-writer is an agent published in the GitHub repository voro6yov/spec-driven-development (5 stars, last pushed 12d ago), licensed Apache-2.0. It adds 42 tokens to every session and 11,835 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-04.

Backend and APIs Commits Git and workflow

git-summary

A Git commit-summary assistant that reads a code diff, meaning the changes between two versions, and writes one short description of the main change.

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Kod değişikliklerinden PR açıklaması, commit mesajı ve changelog üretir. Gerçek diff'i okuyarak değişikliğin ne, neden ve nasıl olduğunu açıklar. Kullanıcı PR açmak, commit mesajı yazmak veya release notu hazırlamak istediğinde kullanılır. Jenerik açıklama üretmez — her zaman gerçek değişikliğe özgü yazar.

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rest-api-updates-writer