ctx AGENTS.md

Repository instructions for contributing to ctx, a Rust package that installs the ctx command-line tool. They describe the project’s supported Rust version, documentation locations, versioning rules, and compatibility requirements.

In plain words
What is it for?
Use them before modifying ctx to find the required governance documents, follow versioning rules, keep internal policies out of public docs, and validate changes against project invariants.
Why use it?
They reduce the risk of breaking command-line behavior, saved data formats, APIs, or the project’s release process when changing the code.

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/agentis-tools/ctx/agents-md
Clone the repo
git clone --depth 1 https://github.com/agentis-tools/ctx

Made for: Codex, OpenCode.

Per session 566 This file is loaded in full into every session.
When invoked 566 The same file — it is already loaded in full.
Security scan C 1 finding. 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 $0.00566 $0.00566
Opus 5 $0.00283 $0.00283
Sonnet 5 $0.00113 $0.00113
Haiku 4.5 $0.00057 $0.00057

Measured 2d ago against content hash cec3c97e6ef2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

ctx AGENTS.md scanned grade C 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 2d 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.

Hidden instructionshighPrompt injection

Directives inside HTML comments, invisible characters or bidirectional overrides are read by the model and not by the person reviewing the file.

<!-- governance-instructions:v1 -->
AGENTS.md · 55 lines

How it starts

The opening of the file, as written. The whole thing — 55 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ctx contributor instructions

ctx is the agentis-ctx Rust package and installs the ctx binary. The root package is not a Cargo workspace; perf/ is an isolated, unpublished harness. Rust 1.91 is the minimum supported version and the edition is 2021.

Read before changing the repository

docs/ is public product documentation and the user manual. Internal policy, maintainer procedures, CI governance, and agent rules belong in governance/, never in docs/.

Invariants

  • Root Cargo.toml [package].version is the only manually edited product version. Use python3 scripts/version.py; do not hand-edit lockfile versions.
  • Ordinary PRs do not bump versions. Release preparation must use the tooling, update reviewed changelog notes, and receive the required labels/review.
  • Treat CLI flags/defaults, JSON, config, persisted schemas/indexes, Rust API, MCP/plugins, exits, platforms/packaging, and self-update as contracts.
  • Add an Unreleased CHANGELOG.md entry for product behavior. Never hide a break in prose or update a contract snapshot without reviewing SemVer impact.
  • Generated harness hooks/plugins/checksums/release notes are not hand-edited.
  • Never tag, publish, release, push unrelated changes, weaken gates, or change repository settings without explicit authorization.

Validation

python3 scripts/version.py show
python3 scripts/check-governance.py check
python3 -m unittest discover -s tests/versioning -p 'test_*.py'
cargo fmt --all -- --check
cargo clippy --all-targets --all-features -- -D warnings
cargo test --locked --all-features
cargo test --locked --no-default-features
scripts/ci.sh

Read the full file on GitHub · 55 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. 2d ago First seen · 55 lines · 566 tokens per session scan C cec3c97e6ef2

Subscribe to this mod's changes

ctx AGENTS.md is an instructions file published in the GitHub repository agentis-tools/ctx (11 stars, last pushed 15d ago), licensed Apache-2.0. It adds 566 tokens to every session, about $0.0028 per session on Opus 5. A static security scan graded it C with 1 finding (hidden instructions). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.