worktree-path-construction

worktree-path-construction is an agent for coding agents from liza-mas/liza. It costs 0 tokens per session (403 once invoked), scanned A, original, Apache-2.0.

A path-safety rule for task worktrees, which are separate working folders for individual changes. It ensures relative paths start at the correct worktree folder instead of adding the task ID twice.

In plain words
What is it for?
Use it when reading or writing files inside a task worktree, especially when paths are built from worktree variables.
Why use it?
It prevents file-not-found errors caused by constructing paths such as `.worktrees/task-id/task-id/...`. A guard can reject paths that contain this duplication.

Agent

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 agents/liza-mas/liza/worktree-path-construction
Clone the repo
git clone --depth 1 https://github.com/liza-mas/liza

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.

agentmods badge for worktree-path-construction

README.md
[![agentmods](https://agentmods.dev/badge/agents/liza-mas/liza/worktree-path-construction.svg)](https://agentmods.dev/agents/liza-mas/liza/worktree-path-construction)
Your own site
<a href="https://agentmods.dev/agents/liza-mas/liza/worktree-path-construction"><img src="https://agentmods.dev/badge/agents/liza-mas/liza/worktree-path-construction.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 403 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00000 $0.00403
Opus 5 $0.00000 $0.00201
Sonnet 5 $0.00000 $0.00081
Haiku 4.5 $0.00000 $0.00040

Measured 5d ago against content hash aec4b04bb2b9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

worktree-path-construction 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 5d 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.

lessons/agents/worktree-path-construction.md · 28 lines

What it actually says

The worktree root already ends in the task id: .worktrees/<task-id>. Relative paths inside the worktree are rooted there — you do NOT prepend the task id again.

Anti-pattern observed (burned 72 turns before self-diagnosing):

/path/to/project/.worktrees/my-task-id/my-task-id/specs/plans/...
                            ^^^^^^^^^ ^^^^^^^^^
                            worktree  (duplicate, always wrong)

This happens when the agent holds two fragments in memory — the absolute worktree root AND a task-named relative path — and concatenates them without noticing the overlap. Every access returns ENOENT for a file that exists one level up, and the agent often fails to recognize the pattern.

Rules:

  1. Every path variable ({{.WorktreePath}}, {{.Worktree}}) already points at .worktrees/<task-id>. Join only with the path below that root.
  2. If you catch yourself typing .worktrees/<id>/<id>/, strip one segment.
  3. If you see repeated ENOENT on paths that "should exist," immediately run ls on the parent dir to confirm the layout before constructing more paths.

Runtime guard: A PreToolUse hook (worktree-path-guard.sh) denies Read/Write/Edit calls whose file_path matches .worktrees/<id>/<id>/. The deny reason names the duplicate segment so the fix is obvious.

Related lesson: worktree-file-path-consistency.md covers a different quirk — Claude Code's Edit tool tracking reads by exact string match. Same overall prescription (use the path variable, don't reconstruct), different root cause.

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. 5d ago First seen · 28 lines · 0 tokens per session scan A aec4b04bb2b9

Subscribe to this mod's changes

worktree-path-construction is an agent published in the GitHub repository liza-mas/liza (364 stars, last pushed 3d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 403 tokens. 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 2026-08-30.