MTHDS Plugins

A skills plugin for Claude Code and OpenAI Codex for building, running, validating, and editing AI methods (.mthds bundle files).

MTHDS is an open standard for AI methods. Find methods on the hub: MTHDS Hub. Install the reference python runtime from Pipelex.

Install for Claude Code

Open Claude Code and paste this. Claude does the rest.

Install mthds: run bash -c 'npm install -g mthds && mthds-agent bootstrap && claude plugin marketplace add mthds-ai/mthds-plugins && claude plugin install mthds@mthds-plugins'. Then tell me to /reload-plugins.

Manual install (Claude Code)

npm install -g mthds
mthds-agent bootstrap
claude plugin marketplace add mthds-ai/mthds-plugins
claude plugin install mthds@mthds-plugins

Install for Codex

Open Codex and paste this. Codex does the rest.

Install mthds: run bash -c 'npm install -g mthds && mthds-agent bootstrap && mthds-agent codex apply-config && codex plugin marketplace add mthds-ai/mthds-plugins'. Then tell me to restart Codex and run /plugins to install mthds.

Requires Codex 0.130.0+ (plugin-bundled hooks shipped in 0.130). Bump with npm install -g @openai/codex@latest if needed.

Manual install (Codex)

npm install -g mthds
mthds-agent bootstrap                # uv + plxt + pipelex-agent
mthds-agent codex apply-config       # set up ~/.codex/ for the mthds plugin
codex plugin marketplace add mthds-ai/mthds-plugins
# Restart Codex, then run /plugins to install mthds

The .mthds validation hook ships inside the plugin (hooks/codex-hooks.json, declared in the Codex plugin manifest); Codex discovers it directly once the plugin is installed — there is no per-user hook wiring step.

mthds-agent codex apply-config makes one-time additive changes to ~/.codex/config.toml:

• [features] plugin_hooks = true — Codex only loads plugin-bundled hooks when this is enabled.
• [sandbox_workspace_write] network_access = true — Codex's default workspace-write sandbox otherwise blocks outbound network for hook commands.

It also removes any obsolete ~/.codex/hooks.json entry left by older mthds installs (which used a now-retired install-hook step). The command is idempotent and never overwrites unrelated config — use --dry-run to preview, --check for CI/env-check. See docs/codex-vs-claude-hooks.md.

If mthds gets installed without this step (for example, added straight from the marketplace UI), the skills catch it: their Step 0 env-check detects the gap and offers to run apply-config for you. Running it up front just avoids building your first method before the validation hook is live.

Skills

Skills work identically on both Claude Code (/skill-name) and Codex ($skill-name).

| Skill | Description | |:------|:------------| | mthds-upgrade | Upgrade MTHDS stack to latest version | | mthds-build | Build new AI method bundles from scratch | | mthds-check | Validate workflow bundles (read-only) | | mthds-edit | Modify existing bundles | | mthds-explain | Explain and document workflows | | mthds-fix | Auto-fix validation errors | | mthds-run | Execute methods and interpret output | | mthds-inputs | Prepare inputs: templates, synthetic data, files | | mthds-install | Install method packages from GitHub or local | | mthds-runner-setup | Set up inference backends and API keys | | mthds-pkg | Manage MTHDS packages (init, deps, lock) | | mthds-publish | Publish methods to mthds.sh | | mthds-share | Share methods on social media | | mthds-vibe | Write a complete MTHDS bundle directly in a single pass |

Automatic validation

Both plugins include hooks that validate .mthds files automatically:

1. Lint — plxt lint validates TOML structure and schema 2. Format — plxt fmt auto-formats the file 3. Validate — mthds-agent validate bundle checks semantic correctness

Claude Code: A PostToolUse hook matches Write/Edit and receives the file path directly. Errors block the edit immediately.

Codex: A PostToolUse hook matches apply_patch (Codex's file-write tool) and parses the patch envelope to find every touched .mthds file. Same per-edit validation, same immediate feedback.

Missing tools (plxt, mthds-agent) block .mthds edits until installed.

License

MIT — Copyright (c) 2026 Evotis S.A.S.

Maintained by Pipelex. "Pipelex" is a trademark of Evotis S.A.S.