besser-dev

besser-dev is a skill for Claude Code, Codex from BESSER-PEARL/BESSER-Skills. It costs 250 tokens per session (981 once invoked), scanned A, original, Apache-2.0.

A contributor guide for developing BESSER, a Python project for model-driven software generation, inside its source tree.

In plain words
What is it for?
It helps add generators, metamodels, and sub-DSLs, write pytest tests, install documentation dependencies, and verify contributions.
Why use it?
It explains the project's setup and contribution procedures so changes follow its expected structure and tests.

Skill for Claude CodeCodex

Which agent this was written for is unclear — built for cline. Also seen: mentions CLAUDE.md; mentions Claude Code; built for cline.

Good fit It helps add generators, metamodels, and sub-DSLs, write pytest tests, install documentation dependencies, and verify contributions.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/besser-pearl/besser-skills/besser-dev
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.

Any agent
npx skills add BESSER-PEARL/BESSER-Skills --skill besser-dev
Clone the repo
git clone --depth 1 https://github.com/BESSER-PEARL/BESSER-Skills

Made for: Claude Code, Codex.

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 besser-dev

README.md
[![agentmods](https://agentmods.dev/badge/skills/besser-pearl/besser-skills/besser-dev/github.svg)](https://agentmods.dev/skills/besser-pearl/besser-skills/besser-dev)
Your own site
<a href="https://agentmods.dev/skills/besser-pearl/besser-skills/besser-dev"><img src="https://agentmods.dev/badge/skills/besser-pearl/besser-skills/besser-dev/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 besser-dev

Your own site · 80×15
<a href="https://agentmods.dev/skills/besser-pearl/besser-skills/besser-dev"><img src="https://agentmods.dev/badge/skills/besser-pearl/besser-skills/besser-dev.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 250 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 981 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00250 $0.00981
Opus 5 $0.00125 $0.00491
Sonnet 5 $0.00050 $0.00196
Haiku 4.5 $0.00025 $0.00098

Measured 12d ago against content hash 608b04db9ca8, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

besser-dev 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.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/scaffold_generator.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills/besser-dev/SKILL.md · 90 lines

How it starts

The opening of the file, as written. The whole thing — 90 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Contributing to BESSER

This skill covers the procedural workflows for contributing to the BESSER codebase. For architecture details and code conventions, also consult the BESSER repo's CLAUDE.md (auto-loaded in Claude Code; with other agents, read CLAUDE.md at the repo root directly).


Development Setup

git clone https://github.com/<your-username>/BESSER.git
cd BESSER
python -m venv venv
# Windows: venv\Scripts\activate
# macOS/Linux: source venv/bin/activate
pip install -r requirements.txt
pip install -r docs/requirements.txt  # for building docs
pip install -e .                       # editable install

Verify: python tests/BUML/metamodel/structural/library/library.py

Python 3.11+ is required (enforced by python_requires = >=3.11 in setup.cfg; CI tests 3.11 and 3.12).


Reference layout

This skill keeps SKILL.md short. Reach into references/ for the procedure you need:

Task Read
Add a new generator (the most common contribution) — 6 steps + scaffold references/adding-a-generator.md
Add a new metamodel / sub-DSL, plus JSON↔BUML converters references/adding-a-metamodel.md
Write pytest tests (fixtures, tmp_path, what to assert) references/testing.md
Build the Sphinx docs and cross-reference them references/docs-and-build.md
Code style, commit/PR conventions, cross-repo, CI/release references/contributing-workflow.md

Related skills for the using side (not contributing):

  • Running or customizing an existing generator → the besser-generators skill.
  • Diagnosing install/import/generation errors → the besser-troubleshooting skill.
  • The user-facing shape of a model type (doc templates) → the besser-user skill's references/.

Common Contribution Pitfalls

  1. Don't duplicate logic — shared helpers go in besser/utilities/, not in individual generators.
  2. Maintain determinism — generators must produce identical output for identical input.
  3. Keep converters symmetric — if JSON → BUML supports a feature, BUML → JSON must too.
  4. Update docs — any backend change likely needs docs/source/ updates.
  5. Don't touch the frontend submodule unless explicitly required. UI changes go to the upstream WME repo.
  6. Clean up resources — always use try/finally for temp directories and file handles.
  7. Test round-trips — especially for converters (JSON → BUML → JSON should be identity).

Read the full file on GitHub · 90 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 First seen · 90 lines · 250 tokens per session scan A 608b04db9ca8

Subscribe to this mod's changes

besser-dev is a skill published in the GitHub repository BESSER-PEARL/BESSER-Skills (8 stars, last pushed today), licensed Apache-2.0. It adds 250 tokens to every session and 981 once invoked, about $0.0013 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.