feature-development

A set of rules for implementing a requested software feature with focused changes and verification. It treats the referenced project as the place where the work should be made.

In plain words
What is it for?
Use it when building or modifying a feature in an existing project and verifying that it behaves as intended.
Why use it?
It keeps implementation work limited to the requested feature and avoids reporting completion without checking the result.

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/agentpipe/pipebuilder/feature-development
Clone the repo
git clone --depth 1 https://github.com/agentpipe/pipebuilder

Made for: Cursor.

Per session 39 This file is loaded in full into every session.
When invoked 39 The same file — it is already loaded in full.
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 $0.00039 $0.00039
Opus 5 $0.00019 $0.00019
Sonnet 5 $0.00008 $0.00008
Haiku 4.5 $0.00004 $0.00004

Measured yesterday against content hash a8414027c6cd, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

feature-development 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 yesterday.

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.

examples/multi-pipeline-project/shared-skills/feature-implementation/.pipe-agents/cursor/.cursor/rules/feature-development.mdc · 7 lines

What it actually says

Treat the referenced project as the implementation target. Keep edits scoped to the requested feature and verify behavior before reporting completion.

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. yesterday First seen · 7 lines · 39 tokens per session scan A a8414027c6cd

Subscribe to this mod's changes

feature-development is a cursor rule published in the GitHub repository agentpipe/pipebuilder (2 stars, last pushed 1mo ago), licensed MIT. It adds 39 tokens to every session, about $0.0002 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.