libthumbor AGENTS.md

AGENTS.md instructions for thumbor/libthumbor, covering agents.md, dev environment setup, running tests, code style and project structure.

Instructions file for CodexOpenCode

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 instructions/thumbor/libthumbor/agents-md
Clone the repo
git clone --depth 1 https://github.com/thumbor/libthumbor

Made for: Codex, OpenCode.

Per session 679 This file is loaded in full into every session.
When invoked 679 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 $0.00679 $0.00679
Opus 5 $0.00340 $0.00340
Sonnet 5 $0.00136 $0.00136
Haiku 4.5 $0.00068 $0.00068

Measured today against content hash 87475304754e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

libthumbor AGENTS.md 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 today.

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.

AGENTS.md · 91 lines

How it starts

The opening of the file, as written. The whole thing — 91 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

libthumbor is a Python library for composing and signing thumbor image URLs. It provides helpers for secure URL generation, URL parsing, and integration points that other applications can use to talk to thumbor safely.

Dev environment setup

  • Prerequisites: Python 3.10+ and Poetry

  • Install project and development dependencies:

    make setup
    

    Equivalent to: poetry install

  • If you prefer running commands directly, use poetry run ... so the virtual environment stays consistent with CI and local development.

Running tests

  • Full local validation flow:

    make test
    
  • Individual targets:

    make unit
    make coverage
    make flake8
    make pylint
    
  • The test suite runs with pytest and collects coverage for the libthumbor package.

Code style

  • Formatter: black with line length 88 and Python 3.10 target, configured in pyproject.toml.
  • Linter: flake8 with max complexity 20, configured in .flake8.
  • Static analysis: pylint, configured in .pylintrc.
  • Primary workflow commands live in the Makefile; prefer them over ad hoc shell commands when possible.

Project structure

libthumbor/              <- main package
  __init__.py            <- package exports
  crypto.py              <- secure URL generation helpers
  url.py                 <- URL composer and parsing utilities
tests/                   <- pytest suite
  test_cryptourl.py      <- signing and encrypted URL behavior
  test_libthumbor.py     <- package-level behavior
  test_url.py            <- URL parsing and composition
  test_url_composer.py   <- URL builder coverage
  test_generic_views.py  <- Django integration coverage
README.md                <- project overview and usage example
CONTRIBUTING.md          <- contribution workflow notes
Makefile                 <- common setup, test, and lint tasks
pyproject.toml           <- Poetry metadata and tool configuration

Read the full file on GitHub · 91 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. today First seen · 91 lines · 679 tokens per session scan A 87475304754e

Subscribe to this mod's changes

libthumbor AGENTS.md is an instructions file published in the GitHub repository thumbor/libthumbor (64 stars, last pushed yesterday), licensed MIT. It adds 679 tokens to every session, about $0.0034 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 2026-09-01.