Borrowing it
Nothing to install: this file belongs to thumbor/libthumbor. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/thumbor/libthumbor/master/AGENTS.mdgit clone --depth 1 https://github.com/thumbor/libthumborWrote 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.
[](https://agentmods.dev/instructions/thumbor/libthumbor/agents-md)<a href="https://agentmods.dev/instructions/thumbor/libthumbor/agents-md"><img src="https://agentmods.dev/badge/instructions/thumbor/libthumbor/agents-md/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.
<a href="https://agentmods.dev/instructions/thumbor/libthumbor/agents-md"><img src="https://agentmods.dev/badge/instructions/thumbor/libthumbor/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00687 | $0.00687 |
| Opus 5.5 | $0.00275 | $0.00275 |
| Sonnet 5.5 | $0.00137 | $0.00137 |
| Haiku 4.5 | $0.00069 | $0.00069 |
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 11d 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.
How it starts
The opening of the file, as written. The whole thing — 92 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 3.11+ and uv
-
Install project and development dependencies:
make setupEquivalent to:
uv sync -
If you prefer running commands directly, use
uv 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
pytestand collects coverage for thelibthumborpackage.
Code style
- Formatter:
blackwith line length 88 and Python 3.11 target, configured in pyproject.toml. - Linter:
flake8with 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 <- project metadata, dependencies and tool configuration
uv.lock <- locked dependency versions
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.
- 11d ago Changed · +1 lines · +8 tokens per session 10fecd161c52
- 1mo ago First seen · 91 lines · 679 tokens per session scan A 87475304754e
libthumbor AGENTS.md is an instructions file published in the GitHub repository thumbor/libthumbor (63 stars, last pushed yesterday), licensed MIT. It adds 687 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 2026-09-01.
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