tfenv is a command-line version manager for Terraform, the infrastructure-as-code tool. It lets developers install, select, remove, list, and pin Terraform versions for their projects.
Borrowing it
Nothing to install: this file belongs to tfutils/tfenv. 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/tfutils/tfenv/master/AGENTS.mdgit clone --depth 1 https://github.com/tfutils/tfenvWrote 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/tfutils/tfenv/agents-md)<a href="https://agentmods.dev/instructions/tfutils/tfenv/agents-md"><img src="https://agentmods.dev/badge/instructions/tfutils/tfenv/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/tfutils/tfenv/agents-md"><img src="https://agentmods.dev/badge/instructions/tfutils/tfenv/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 | $0.03018 | $0.03018 |
| Opus 5.5 | $0.01207 | $0.01207 |
| Sonnet 5.5 | $0.00604 | $0.00604 |
| Haiku 4.5 | $0.00302 | $0.00302 |
Grade A, and why
tfenv AGENTS.md scanned grade A 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
- **Minimal dependencies:** bash, curl, grep/ggrep, sort, unzip How it starts
The opening of the file, as written. The whole thing — 326 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent Guidelines for tfutils/tfenv
Master context document for AI coding agents contributing to this repository. Every agent MUST read this file before starting work.
Project Overview
tfenv is a Terraform version manager written in Bash, modelled after rbenv.
~2.5k LOC across bin/, lib/, libexec/, test/, and share/.
- Language: Bash (no shellcheck — deliberate choice; see ADR-0003)
- Default branch:
master - Current release: v3.2.0 (April 2026)
- Maintainer: Mike Peachey / Jaz (@Zordrak)
- Minimal dependencies: bash, curl, grep/ggrep, sort, unzip
- License: MIT
Repository Structure
bin/ Entry points (terraform shim, tfenv command)
lib/ Shared libraries sourced by multiple scripts
libexec/ Subcommands (tfenv-install, tfenv-use, etc.)
test/ Integration tests (download real Terraform binaries)
share/ Static assets (HashiCorp PGP keys)
.github/ CI workflows, agent definitions, issue templates
agents/ Agent definition files (.agent.md)
instructions/ Auto-loaded coding standards
ISSUE_TEMPLATE/ Structured issue forms
docs/
adr/ Architecture Decision Records
Core Principles
1. Standalone Script Execution
Every libexec/ script contains its own boilerplate for resolving
TFENV_ROOT and sourcing helpers. This is intentional — each script
must be executable in isolation. Do NOT refactor this into a shared loader.
See ADR-0002.
2. Worktree-First
ALL code changes MUST happen in a git worktree under .worktrees/. The main
working tree is shared by all agents and the human — modifying it directly
risks conflicts. .worktrees/ is gitignored.
# Create a worktree for your work
git worktree add .worktrees/fix-123 -b fix/123-description master
# Do all work inside the worktree
cd .worktrees/fix-123
# Clean up when done (after PR is created)
cd /path/to/main/tree
git worktree remove .worktrees/fix-123
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.
- 2mo ago First seen · 326 lines · 3,018 tokens per session scan A 5ee2cb5714d6
tfenv AGENTS.md is an instructions file published in the GitHub repository tfutils/tfenv (4,991 stars, last pushed 4mo ago), licensed MIT. It adds 3,018 tokens to every session, about $0.0121 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
tfenv AGENTS.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| tfenv AGENTS.mdtfutils/tfenv | Instructions file | 5.0k | 4mo ago | MIT | A | 3,018 | Codex, OpenCode |
| plan-forge naming.instructions.mdsrnichols/plan-forge | Instructions file | 6 | 2d ago | MIT | A | 1,453 | GitHub Copilot |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | today | MIT | A | 7,461 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 5,516 | GitHub Copilot |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | today | MIT | A | 4,680 | Codex, OpenCode |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 3,093 | GitHub Copilot |