ECC: Instructions file for Kiro

.kiro/steering/lessons-learned.md

lessons-learned is an instructions file for Kiro from affaan-m/ECC. It costs 671 tokens per session, scanned A, original, MIT.

A project-owned note for recording patterns, team preferences, recurring mistakes, and architectural decisions discovered during development. It is intended to be edited over time rather than treated as general advice.

In plain words
What is it for?
Use it to document project-specific API rules, style preferences, known pitfalls, and useful patterns learned from previous work.
Why use it?
It gives future coding sessions a place to find decisions and conventions that are specific to the project.

Instructions file for Kiro

Written for Kiro: installed under .kiro/.

This is affaan-m/ECC's own configuration. It tells Kiro how to work on ECC itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything ECC configures →

About the project

ECC is a toolkit that organizes and improves how coding agents work through skills, memory, security checks, research practices, and related extensions. It is for developers using agents such as Claude Code, Codex, OpenCode, and Cursor.

affaan-m/ECC · 287,323 stars · on GitHub · ecc.tools

Reuse

Borrowing it

Nothing to install: this file belongs to affaan-m/ECC. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/affaan-m/ECC/main/.kiro/steering/lessons-learned.md
Clone the repo
git clone --depth 1 https://github.com/affaan-m/ECC

Made for: Kiro.

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 lessons-learned

README.md
[![agentmods](https://agentmods.dev/badge/instructions/affaan-m/ecc/lessons-learned/github.svg)](https://agentmods.dev/instructions/affaan-m/ecc/lessons-learned)
Your own site
<a href="https://agentmods.dev/instructions/affaan-m/ecc/lessons-learned"><img src="https://agentmods.dev/badge/instructions/affaan-m/ecc/lessons-learned/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.

agentmods 80×15 button for lessons-learned

Your own site · 80×15
<a href="https://agentmods.dev/instructions/affaan-m/ecc/lessons-learned"><img src="https://agentmods.dev/badge/instructions/affaan-m/ecc/lessons-learned.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 671 This file is loaded in full into every session.
When invoked 671 The same file — it is already loaded in full.
Security scan A 0 findings. 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00671 $0.00671
Opus 5.5 $0.00268 $0.00268
Sonnet 5.5 $0.00134 $0.00134
Haiku 4.5 $0.00067 $0.00067

Measured 12d ago against content hash c8de11e955f8, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

lessons-learned 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 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.

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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.kiro/steering/lessons-learned.md · 86 lines

How it starts

The opening of the file, as written. The whole thing — 86 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Lessons Learned

This file captures project-specific patterns, coding preferences, common pitfalls, and architectural decisions that emerge during development. It serves as a workaround for continuous learning by allowing you to document patterns manually.

How to use this file:

  1. The extract-patterns hook will suggest patterns after agent sessions
  2. Review suggestions and add genuinely useful patterns below
  3. Edit this file directly to capture team conventions
  4. Keep it focused on project-specific insights, not general best practices

Project-Specific Patterns

Document patterns unique to this project that the team should follow.

Example: API Error Handling

// Always use our custom ApiError class for consistent error responses
throw new ApiError(404, 'Resource not found', { resourceId });

Code Style Preferences

Document team preferences that go beyond standard linting rules.

Example: Import Organization

// Group imports: external, internal, types
import { useState } from 'react';
import { Button } from '@/components/ui';
import type { User } from '@/types';

Kiro Hooks

install.sh is additive-only — it won't update existing installations

The installer skips any file that already exists in the target (if [ ! -f ... ]). Running it against a folder that already has .kiro/ will not overwrite or update hooks, agents, or steering files. To push updates to an existing project, manually copy the changed files or remove the target files first before re-running the installer.

README.md mirrors hook configurations — keep them in sync

The hooks table and Example 5 in README.md document the action type (runCommand vs askAgent) and behavior of each hook. When changing a hook's then.type or behavior, update both the hook file and the corresponding README entries to avoid misleading documentation.

Prefer askAgent over runCommand for file-event hooks

runCommand hooks on fileEdited or fileCreated events spawn a new terminal session every time they fire, creating friction. Use askAgent instead so the agent handles the task inline. Reserve runCommand for userTriggered hooks where a manual, isolated terminal run is intentional (e.g., quality-gate).

Read the full file on GitHub · 86 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. 12d ago Changed c8de11e955f8
  2. 1mo ago First seen · 86 lines · 671 tokens per session scan A adae87c6158f

Subscribe to this mod's changes

lessons-learned is an instructions file published in the GitHub repository affaan-m/ECC (287,323 stars, last pushed 3d ago), licensed MIT. It adds 671 tokens to every session, about $0.0027 per session on Opus 5.5. 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 2026-09-07.

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