mthds-install

name	mthds-install
description	Install MTHDS method packages from GitHub or local directories. Use when user says "install a method", "install from GitHub", "add a method package", "mthds install", "install method", "set up a method", or wants to install an MTHDS method package for use with an AI agent.
min_mthds_version	0.12.1

Install MTHDS method packages

Install method packages from GitHub or local directories using the mthds-agent CLI.

Process

Step 0 — Environment Check (mandatory, do this FIRST)

Run this command to check toolchain status:

# Wrapped in `bash -c` so the bash array syntax below works even when the
# session shell is zsh (Codex runs blocks under the user's shell).
bash -c '
# Pick the cached env-check from the plugin version with the highest semver.
# Pad each numeric segment to fixed width so lex sort matches semver sort
# (avoids the 0.10 < 0.9 lex-order trap). Sort keys are digits-only by
# construction, so the [[ > ]] compare is locale-independent. Bash 3.2 OK.
_best_f=""; _best_k=""
for f in "${CODEX_HOME:-$HOME/.codex}"/plugins/cache/*/mthds/*/bin/mthds-env-check; do
  [ -x "$f" ] || continue
  _v="${f%/bin/*}"; _v="${_v##*/}"
  _k=""; IFS=. read -ra _parts <<<"${_v%%[-+]*}"
  for _p in "${_parts[@]}"; do _p=${_p%%[!0-9]*}; _k="${_k}$(printf %06d "${_p:-0}")"; done
  [[ "$_k" > "$_best_k" ]] && { _best_f="$f"; _best_k="$_k"; }
done
[ -n "$_best_f" ] && exec "$_best_f" "0.12.1" --codex
echo "MTHDS_ENV_CHECK_MISSING"
'

Interpret the output:

• MTHDS_AGENT_MISSING → STOP. Do not proceed. Tell the user:

The mthds-agent CLI is required but not installed. Install it with:

npm install -g mthds

Then re-run this skill.

• MTHDS_AGENT_VERSION_UNKNOWN → STOP. The installed mthds-agent returned an unparseable version. Tell the user:

Could not parse the output of mthds-agent --version. Your installation may be corrupt. Reinstall with:

npm install -g mthds@latest

Then re-run this skill.

• MTHDS_AGENT_OUTDATED <installed> <required> → The installed mthds-agent is too old for this plugin. Do not hard-stop. Instead, tell the user their mthds-agent (v<installed>) is older than the required v<required>, then follow the upgrade flow to offer upgrading mthds-agent via npm install -g mthds@latest. After the upgrade flow completes (whether the user upgraded or declined), proceed to Step 1. The upgrade flow's "Not now" and "Never ask" options let users continue with current versions.

• MTHDS_UPDATE_CHECK_FAILED ... → WARN. The update check command failed. Show the error output to the user. Suggest checking network connectivity and mthds-agent installation. Proceed to Step 1 with current versions.

• UPGRADE_AVAILABLE ... → Read upgrade flow and follow the upgrade prompts before continuing to Step 1.

• JUST_UPGRADED ... → Announce what was upgraded to the user, then continue to Step 1.

• UP_TO_DATE ... → Proceed to Step 1. The line is a terse list of verified installed versions (e.g. UP_TO_DATE mthds-agent=0.10.0 plxt=0.4.0 plugin=0.12.0); if you mention the env-check in your preamble acknowledgement, relay the agent and plugin versions you saw. Two "explicit-quiet" variants share the same prefix and are also clean — proceed to Step 1 without warning, and do not relay the quiet state unless the user is troubleshooting:

  • UP_TO_DATE update-check=disabled — the user has turned update-check off via config.
  • UP_TO_DATE update-check=snoozed — the user has an active snooze on the current version key; an upgrade would otherwise be available, but they explicitly asked for quiet.

• No output → WARN. The env-check produced no output at all, which usually means mthds-agent itself is broken or the wrapper script bailed before printing. Tell the user the environment check could not be confirmed, then proceed cautiously to Step 1.

• MTHDS_ENV_CHECK_MISSING → WARN. The env-check script was not found at either expected path. Tell the user the environment check could not run, but proceed to Step 1.

• CODEX_CONFIG_NEEDS_SETUP → Codex's ~/.codex/ is not set up for the mthds plugin, so the bundled .mthds validation hook will not load. When this fires it is the only terminal status the env-check emits — update-check is skipped entirely (not run, not suppressed) because fixing the hook is the prerequisite and update-check's upgrade marker is one-shot; the user re-runs and gets fresh update info next time. The env-check may print one or more #-prefixed diagnostic lines after the status — relay them if present. Resolve this before Step 1:

  1. Preview — run mthds-agent codex apply-config --dry-run and show the user the output. WOULD_APPLY lists the keys it will add under applied; ALREADY_OK means no keys need adding. Either way, relay any warnings entries — those (e.g. read-only sandbox, hooks disabled) need a hand-fix apply-config will not perform. If ALREADY_OK with no warnings, treat as resolved and go to Step 1.
  2. Ask — use AskUserQuestion: "Apply Codex config now?" with options "Apply now" / "Skip".
  3. Apply now — run mthds-agent codex apply-config:
     • APPLIED / ALREADY_OK → tell the user the config is fixed and they must restart Codex for the validation hook to load (it will not load in this session). Relay any warnings — those still need a hand-fix.
     • Error about conflicting keys → show it verbatim; the user must hand-edit ~/.codex/config.toml, then re-run mthds-agent codex apply-config.
     • Error from the sandbox blocking the write to ~/.codex/config.toml → ask the user to run mthds-agent codex apply-config themselves in a terminal, then restart Codex.
  4. Skip — tell the user the validation hook stays off until they run mthds-agent codex apply-config and restart Codex.

  Then proceed to Step 1. This session has no PostToolUse hook. The mthds skills still run mthds-agent validate bundle explicitly, so .mthds files built or edited through a skill are still semantically validated — but the write-time plxt lint/fmt pass depends on the hook and will not run until Codex is restarted.

• Any other output → WARN. The preamble produced unexpected output. Show it to the user verbatim. Proceed to Step 1 cautiously.

Do not attempt manual installation. The CLI handles resolution, file placement, shim generation, and runtime setup.

No backend setup needed: This skill works without configuring inference backends or API keys. You can start building/validating methods right away. Backend configuration is only needed to run methods with live inference — use /mthds-runner-setup when you're ready.

Step 1: Identify the Source

Determine where the method package lives:

Source	Syntax	Example
GitHub (short)	org/repo	mthds-ai/contract-analysis
GitHub (full URL)	https://github.com/org/repo	https://github.com/mthds-ai/contract-analysis
Local directory	--local <path>	--local ./my-methods/

If the user provides a GitHub URL or org/repo string, use it as the address argument. If they point to a local directory, use --local.

Step 2: Choose Install Parameters

Flag	Required	Values	Description
--location	Yes	local, global	local = project .mthds/methods/, global = ~/.mthds/methods/
--method <name>	No	method name	Install only one method from a multi-method package
--no-runner	No	—	Skip automatic Pipelex runtime installation

Method packages always install under .mthds/methods/ regardless of which agent runs the command.

Defaults:

• Use --location local unless the user explicitly asks for global install

Step 3: Run the Install

From GitHub:

mthds-agent install <org/repo> --location local

From a local directory:

mthds-agent install --local <path> --location local

Install a specific method from a multi-method package:

mthds-agent install <org/repo> --location local --method <name>

Step 4: Present Results

On success, the CLI returns JSON:

{
  "success": true,
  "installed_methods": ["method-name"],
  "location": "local",
  "target_dir": "/path/to/.mthds/methods",
  "shim_dir": "~/.mthds/bin",
  "shims_generated": ["method-name"]
}

Present to the user:

• Which methods were installed and where (target_dir)
• If CLI shims were generated, note the shim directory and advise adding ~/.mthds/bin to PATH if not already present

Step 5: Handle Errors

Common errors:

Error	Cause	Fix
--location is required	Missing --location flag	Add --location local or --location global
Failed to resolve methods	GitHub repo not found or no methods in repo	Verify the address and that the repo contains METHODS.toml
Method "X" not found	--method filter doesn't match any method in the package	Check available method names in the package
Failed to install pipelex runtime	Runtime install failed (network, permissions)	Retry, or use --no-runner to skip runtime install

For all error types and recovery strategies, see Error Handling Reference.

Reference

• Error Handling — read when CLI returns an error to determine recovery
• MTHDS Agent Guide — read for CLI command syntax or output format details