Install Rustic Python — instructions for coding agents

When the user asks you to install Rustic Python, perform the installation below with your own file and terminal tools. Do not hand the user a list of shell commands. This installs reference material, not Python dependencies. Installing the skill opts into checking for and applying reference updates when it is used. An explicit user request to pin a revision or disable updates takes precedence.

Choose the destination

Use the host you are currently running in, not the model name or which programs happen to be installed. Install for that host only, unless the user explicitly asks for multiple hosts. Default to personal scope; honor a requested project scope or explicit destination. Ask only if the host or requested location cannot be determined from the conversation and environment.

Expand ~ using the user’s home directory, including on Windows. If the host has an explicitly configured skills directory, use it. These instructions target coding agents with local file access; a browser-only chat cannot install local files and should say so rather than claim success.

Check for updates before use

Check once at the beginning of each task using the skill, including when a new task starts in an existing conversation. Use the folder from which this skill was loaded; do not install a second copy into a different scope.

1. Fetch https://api.github.com/repos/Red-Eyed/rustic-python/commits/main with an HTTP client that checks status codes, a bounded timeout, and cache revalidation (Cache-Control: no-cache). Read the full 40-character hexadecimal sha. This is the target revision for this task. Use commit identity, not package versions or dates: documentation can change between version bumps. Before staging an update, read INSTALL.md from https://raw.githubusercontent.com/Red-Eyed/rustic-python/<full SHA>/INSTALL.md and use that revision’s layout and update instructions. Keep the already resolved target SHA; do not restart the check recursively.
2. Read local rustic-python-source.json. Its format is schema_version: 1, repository: "https://github.com/Red-Eyed/rustic-python", source: {"commit": "<full SHA>", "dirty": false}, and files, a mapping of relative POSIX file paths to SHA-256 hex digests. Verify file hashes before treating the installation as unchanged. Ignore only __pycache__, .pytest_cache, .ruff_cache, and .pyc files. Added, changed, missing, or symlinked reference files count as local modifications. The metadata file itself is excluded from its hash map. Digests detect edits, not authenticity.
3. If the repository matches, source.dirty is false, the commit matches the target, and the files are unchanged, continue using this copy. Otherwise stage the target using the next section. Missing or invalid metadata means unknown provenance, not a current installation.
4. Automatically refresh an unchanged managed installation, then reread the new SKILL.md and needed chapters. Keep this task’s check result so rereading does not trigger an update loop. Report an update with its old/new revisions.

For a user-pinned copy, honor the pin and identify it as pinned. For local edits, dirty builds, unknown provenance, or symlink installations, preserve the installed copy and use the freshly staged reference folder for this task instead; report its path and why the installed copy was not replaced. An explicitly requested update may replace a legacy or edited directory after backing it up. Never write through a symlink or change the user’s checkout automatically.

If GitHub is unavailable, rate-limited, permissions are denied, or no valid staged copy can be obtained, keep the existing copy and disclose its revision (if known) and that freshness could not be verified. Do not claim an offline copy is current. Do not loop on failures; retry on the next task. A first installation without a valid source fails clearly instead of reporting success. Check again when the user explicitly requests an update; otherwise do not poll throughout a task.

Stage the target revision

Perform downloads and file operations yourself. No clone, project dependencies, or execution of downloaded code is required.

1. Fetch the ready-made bundle into a temporary directory: https://red-eyed.github.io/rustic-python/downloads/rustic-python.zip. Require a successful HTTP response. Inspect the archive before extracting: reject absolute paths, parent traversal, symlinks, and duplicate destinations; every entry must stay within its single rustic-python/ root.
2. Extract into staging. Accept this ZIP only when its metadata names the expected repository, records the target commit with dirty: false, and its complete file inventory and hashes match. Reject malformed metadata or escaping paths.
3. If Pages is unavailable or its ZIP does not match, fetch the repository archive for the exact target SHA, never a moving main archive: https://api.github.com/repos/Red-Eyed/rustic-python/zipball/<full SHA>. Follow GitHub’s archive redirect and enforce the same extraction rules, allowing its single generated repository root name. This fallback avoids waiting for Pages deployment; it is repository content, not a claim that CI has passed.
4. Assemble a fresh rustic-python/ folder from that archive: copy README.md, CHANGELOG.md, LICENSE, INSTALL.md, pyproject.toml, uv.lock, pyrefly.toml, ruff.toml, pytest.ini, and the docs/, examples/, tests/ directories. Omit caches, .pyc files, and tests/test_distribution.py. Copy skills/rustic-python/SKILL.md to the folder’s root as SKILL.md. Remove the README line beginning - [AGENTS.md]; do not copy repository maintenance instructions, .git, tools/, or host configuration.
5. For an archive-assembled copy, write the metadata format described above using the target SHA, dirty: false, and SHA-256 digests of all assembled files. Never relabel a stale Pages ZIP as the target revision.
6. Verify SKILL.md has name: rustic-python, required directories and templates exist, and its relative references resolve inside staging. Do not install just SKILL.md. A malformed published bundle may fall back to the repository archive; a malformed fallback must stop the update and preserve the existing copy.

The target is the revision observed at the start of the check. If main advances while downloading, finish this consistent snapshot and check again next task. Do not combine chapters from different revisions.

Install or replace

For a new installation, choose the destination above. For an update, retain the existing destination. Finish staging and validation before touching it.

Create its parent if needed. For replacement, recheck the installed file hashes to catch edits made during downloading. If unchanged, move the old folder to a unique backup outside the host’s skill discovery directories, then move the complete staged folder into place. If replacement or final verification fails, restore the backup. Never merge files over the old directory: deleted chapters must disappear too. Serialize updates to the same destination; if another agent is updating it, use the staged snapshot for this task rather than racing it.

Verify the installed metadata, SKILL.md, and linked references at the final path, then report the revision and backup path. Leave project settings, AGENTS.md, CLAUDE.md, .clinerules, other skills, and dependency environments untouched. Respect normal host file and network permissions; automatic refresh does not bypass those permissions.

Report the result

Give the installed path, the source commit, the version from pyproject.toml, and one invocation example:

• Codex: $rustic-python review this preprocessing pipeline.
• Claude Code: /rustic-python review this preprocessing pipeline.
• Cline: select /rustic-python in chat, then request the review.

If the host exposes skill discovery, check that it lists rustic-python. Otherwise report that the files are installed and ask the user to refresh the skill list or restart the session only if it does not appear. Do not claim a runtime activation test you did not perform.

Updates happen before skill use. Older copies without the refresh instructions need a one-time update using this link. The user may also request an immediate update or explicitly pin a revision. For removal, delete only the installed skill folder or symlink when requested.

Host references: Codex, Claude Code, and Cline.

GitHub references: commit lookup and commit-pinned archives.