trufflesqueak: Instructions file for Codex

AGENTS.md

trufflesqueak AGENTS.md is an instructions file for Codex, OpenCode from hpi-swa/trufflesqueak. It costs 1,043 tokens per session, scanned B, original, MIT.

Repository instructions for AI coding agents working on TruffleSqueak, a Squeak Smalltalk implementation built on the GraalVM runtime. They cover preflight checks, required tools, setup, dependencies, and version matching.

In plain words
What is it for?
Use them to prepare an Ubuntu development environment, install dependencies and hooks, configure GraalVM and mx, and start working on TruffleSqueak.
Why use it?
They reduce setup errors by checking the required Java, Python, CMake, and GraalVM versions before building or troubleshooting.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md.

This is hpi-swa/trufflesqueak's own configuration. It tells Codex and OpenCode how to work on trufflesqueak 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 trufflesqueak configures →

Reuse

Borrowing it

Nothing to install: this file belongs to hpi-swa/trufflesqueak. 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/hpi-swa/trufflesqueak/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/hpi-swa/trufflesqueak

Made for: Codex, OpenCode.

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.

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README.md
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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.

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<a href="https://agentmods.dev/instructions/hpi-swa/trufflesqueak/agents-md"><img src="https://agentmods.dev/badge/instructions/hpi-swa/trufflesqueak/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 1,043 This file is loaded in full into every session.
When invoked 1,043 The same file — it is already loaded in full.
Security scan B 1 finding. 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 $0.01043 $0.01043
Opus 5.5 $0.00417 $0.00417
Sonnet 5.5 $0.00209 $0.00209
Haiku 4.5 $0.00104 $0.00104

Measured 2mo ago against content hash 13f08973085d, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

trufflesqueak AGENTS.md scanned grade B with 1 finding 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 2mo 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.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

sudo apt-get update
AGENTS.md · 95 lines

How it starts

The opening of the file, as written. The whole thing — 95 lines — stays where its author put it; the contents beside it link to each section on GitHub.

TruffleSqueak Agent Reference

Preflight Checks

Run these before spending time on build failures:

java --version
mx --version
python3 --version
cmake --version
python3 -c "import re; print(re.search(r'\"version\"\s*:\s*\"(\d+\.\d+\.\d+)', open('mx.trufflesqueak/suite.py').read()).group(1))"

The GraalVM version should match mx.trufflesqueak/suite.py.

Setup

Prefer the following manual setup below for local development:

# Install dependencies (Ubuntu 24.04)
sudo apt-get update
sudo apt-get install -y build-essential zlib1g-dev cmake python3-pip

# Install Oracle GraalVM matching the current suite version.
# If SDKMAN is available, this is the easiest option:
sdk install java <graalvm-version>-graal
sdk use java <graalvm-version>-graal
# Alternatively, use `mx fetch-jdk`.

# Install pre-commit hooks
python3 -m pip install --user pre-commit
pre-commit install

# Work from the parent directory of the TruffleSqueak checkout
export TS_WORKSPACE="$(cd .. && pwd)"

# Clone mx next to trufflesqueak and add it to PATH
git clone https://github.com/graalvm/mx.git "$TS_WORKSPACE/mx"
export PATH="$TS_WORKSPACE/mx:$PATH"

# Clone graal next to trufflesqueak and apply the checked-in patch
mx sforceimport
(cd "$TS_WORKSPACE/graal" && git apply "$TS_WORKSPACE/trufflesqueak/mx.trufflesqueak/graalvm-<graalvm-version>.patch")

Build and Run

Read mx.trufflesqueak/suite.py first. It is the quickest way to understand project names, imported suites, and distribution names.

# Build JVM standalone (faster to build) and find the target build directory
mx --env jvm build
mx --env jvm paths --output "TRUFFLESQUEAK_JVM_STANDALONE"

# Build native standalone (slower to build) and find the target build directory
mx --env native build --build-log important
mx --env native paths --output "TRUFFLESQUEAK_NATIVE_STANDALONE"

# Launch TruffleSqueak from the standalone's bin/ directory
trufflesqueak --headless --quiet -- --evaluate "<smalltalk code>"

# Run 10 iterations of the Towers benchmark from AWFY
trufflesqueak --headless --quiet -- --evaluate "AWFYHarness run: #('Towers' 10 1500)"

# Run TruffleSqueak tests
trufflesqueak --vm.ea --download-image trufflesqueak-test -- src/image-tests/runSqueakTests.st

# Run Cuis tests
trufflesqueak --vm.ea --download-image cuis-7.5-test -- -s src/image-tests/runCuisTests.st

Read the full file on GitHub · 95 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. 2mo ago First seen · 95 lines · 1,043 tokens per session scan B 13f08973085d

Subscribe to this mod's changes

trufflesqueak AGENTS.md is an instructions file published in the GitHub repository hpi-swa/trufflesqueak (319 stars, last pushed yesterday), licensed MIT. It adds 1,043 tokens to every session, about $0.0042 per session on Opus 5.5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

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deepseek-harness AGENTS.mddeepseek-ai/deepseek-harnessInstructions file274k2d agoMITA4,313Codex, OpenCode