composer-fullstack-delivery

A set of rules for building a complete feature across connected parts of an application, such as the user interface, server, and data storage.

In plain words
What is it for?
Use it for new screens, features, endpoints, database changes, or any other work that crosses multiple application layers.
Why use it?
It keeps the parts connected through clear contracts, error handling, security checks, and a small working path before expanding the feature.

Cursor rule for Cursor

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 rules/madebyaris/cursor-composer-rules/composer-fullstack-delivery
Clone the repo
git clone --depth 1 https://github.com/madebyaris/cursor-composer-rules

Made for: Cursor.

Per session 29 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 998 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00029 $0.00998
Opus 5 $0.00015 $0.00499
Sonnet 5 $0.00006 $0.00200
Haiku 4.5 $0.00003 $0.00100

Measured 2d ago against content hash 7aecb33dcb79, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

composer-fullstack-delivery 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 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- Ad-hoc checks → curl / CLI / browser, captured as artifacts (script, fixture), not throwaway gestures
.cursor/rules/composer-fullstack-delivery.mdc · 81 lines

How it starts

The opening of the file, as written. The whole thing — 81 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Composer full-stack delivery

Use when building or continuing a new screen, feature, endpoint, or any work that spans multiple layers: client + server, server + persistence, service + service, code + migration. Skip when a single-module tweak suffices.

Stack-agnostic: replace "client/server/persistence" with whatever your spine actually is. Complements composer-core § Continue the app + handoff and § Build the app.

Step 1 — Freeze the seams

Before writing code, write the one-sentence acceptance from composer-core §1 ("The user can X and see Y"), then the boundaries (a few bullets, not a doc):

  • User-visible behavior for the smallest useful story
  • Contracts at every seam: API shape, event shape, function signature, error semantics
  • Trust boundaries: actor, authentication, authorization
  • Consistency: transactions, retries, idempotency where partial failure repeats
  • Observability: existing logs/traces/metrics at these seams; minimum new ones

If two of these conflict, surface the conflict before coding around it — often high confusion weight (clarify-first).

Step 2 — Ship one vertical slice

Build a thin column end-to-end before widening:

  1. One client/caller path
  2. One server handler or worker
  3. One persistence or integration edge if persistence is new

Use the minimum UI needed to expose state transitions; defer layout, animation, and polish. The slice is not done until it is demoable at that surface.

Slice-1 floor (same as composer-core § Build the app): one real interaction plus an empty or error state — or name the omission in Wired. A husk form with a stubbed API is not a finished slice unless Wired says so.

Resist the second screen, second endpoint, or speculative migration until the first slice demonstrably works at the surface that matters.

Step 3 — Treat failure modes as first-class

Happy path is half the work. Enumerate at least:

Read the full file on GitHub · 81 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 · 81 lines · 29 tokens per session scan A 7aecb33dcb79

Subscribe to this mod's changes

composer-fullstack-delivery is a cursor rule published in the GitHub repository madebyaris/cursor-composer-rules (3 stars, last pushed 15d ago), licensed MIT. It adds 29 tokens to every session and 998 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.