External Model

Shells out to a different AI model via one of three external agentic CLIs — opencode, cursor-agent, kiro-cli — and returns its answer. Four common requests all reduce to this same mechanism, just framed differently:

1. Second opinion — "what would GPT-5/Gemini say about this?"
2. Delegate a task — "have cursor handle this", "let kiro do it"
3. Pick the best model — "which model is best for this, then run it"
4. Raw run — "run this prompt through opencode"

Don't overthink which framing applies — resolve a CLI/model (see Resolution below) and invoke the dispatcher.

Invocation

Call scripts/run-model.sh, resolved to an absolute path relative to this skill's own directory (e.g. <skill-dir>/scripts/run-model.sh). The prompt is a single positional argument; quote it so multi-line or complex prompts arrive as one argv element.

run-model.sh "prompt"                                   # default: read-only, sandboxed, 120s timeout
run-model.sh --cli <opencode|cursor-agent|kiro-cli> --model <m> "prompt"
run-model.sh --write "prompt"                            # allow file edits in the repo
run-model.sh --all "prompt"                              # every installed CLI, forced read-only, side-by-side
run-model.sh --dry-run "prompt"                            # print resolved command without running
run-model.sh --context <file> "prompt"                     # prepend file contents to prompt
run-model.sh --timeout <sec> "prompt"
run-model.sh detect                                      # list installed CLIs
run-model.sh config show                                 # show resolved config
run-model.sh config set --cli <cli> [--model <m>]        # persist a default

Read-only sandbox tradeoff

Default runs execute in a throwaway temp directory: the external model cannot mutate the repo, but it also cannot see repo files — it has no access to your working tree at all. So a read-only "opinion about this code" request only works if you embed the relevant code/context directly in the prompt yourself before calling the dispatcher. Use --write only when you genuinely want the external model to read and edit files in the real repo — it then runs with repo access and edit permission, not in the sandbox.

--all is the best choice for second-opinion requests: it fans the same prompt out to every installed CLI in parallel and returns the answers side by side, always read-only regardless of --write. It does not forward --model: each CLI runs with its own default model, because model names are not portable across these CLIs. If you also pass --write, the dispatcher prints a one-line note that --write is ignored and proceeds with read-only mode.

Slash usage

• /external-model <prompt> — run a prompt through the resolved default CLI
• /external-model config set --cli opencode --model openai/gpt-5 — persist a default
• /external-model config show — print the resolved config

The shorthands set / show are accepted as aliases for config set / config show (the script treats run-model.sh set ... exactly like run-model.sh config set ..., and run-model.sh show like config show), so neither ever runs a model with a literal "set"/"show" prompt.

Resolution precedence

When the user doesn't pin a CLI explicitly, resolve in this order:

1. Explicit flags on the command (--cli, --model)
2. Repo config .claude/external-model.config
3. Global config ~/.claude/skills/external-model/config
4. If exactly one CLI is installed, use it
5. If several are installed and none is configured as default, **ask the

user which one** — then re-invoke with --cli <their choice>. Do not guess.

Passing --cli alone (no --model) uses that CLI's own default model — it does not inherit a MODEL from config.

Config

config set writes only the global file (~/.claude/skills/external-model/config). A per-repo override at .claude/external-model.config (lines of KEY=VALUE: CLI=..., MODEL=...) is hand-authored by the user — the skill reads it but never writes it. Don't create or edit that file on the user's behalf.

Omitting --model from config set --cli X clears any previously-stored MODEL= line in the global config and leaves the new state as CLI=X only. To restore a model later, run config set --cli X --model M.

Prerequisites

Each CLI (opencode, cursor-agent, kiro-cli) must be installed and authenticated independently of this skill; kiro-cli headless mode specifically requires KIRO_API_KEY to be set. Read references/cli-matrix.md when you need exact per-CLI install checks, invocation flags, model-name formats, or auth/timeout gotchas — don't inline that detail here.

Checklist

Before shipping a change to this skill, verify:

• [ ] name matches the folder name (external-model)
• [ ] description includes trigger phrases ("Use when...") and is under 1024 chars
• [ ] Companion files (scripts/run-model.sh, references/cli-matrix.md) are referenced, not inlined
• [ ] Entry added to README.md and .claude-plugin/plugin.json
• [ ] bash scripts/validate-skills.sh passes