mulmoterminal-model

Run on another model

Three keys, three jobs:

• ~/.mulmoterminal/config.json → providers — register a backend once. No Settings UI.
• <project>/.mulmoterminal.json → provider / model — what this project launches on. Both are defaults; the launch form can override them for a single session.
• ~/.mulmoterminal/config.json → customAgents — the user's own COMMAND for starting Claude Code, offered in the Agent Picker. For when the model is reached by running something else (ollama launch claude …, a wrapper script, a second Claude Code install) rather than by an HTTP endpoint. No Settings UI.

None is needed to use Anthropic's default. Only do this when the user asked for another model.

Which one. A backend that speaks the Anthropic API over HTTP is a providers entry — that is the smaller change and it composes with the model picker. Reach for customAgents only when the thing that runs the model is a command, and the user cannot express it as a base URL and a token.

Registering a backend

{
  "providers": [
    {
      "id": "openrouter",
      "label": "OpenRouter",
      "baseUrl": "https://openrouter.ai/api",
      "tokenEnv": "OPENROUTER_API_KEY",
      "maxOutputTokens": 16000
    }
  ]
}

Each rule below was measured against a working setup, and each breaks the session in a way that is hard to diagnose from inside it:

• baseUrl must not end in /v1. Claude Code appends /v1/messages itself, so a trailing /v1 produces /v1/v1/messages and every request 404s.
• Never write the API key into a config or skill file. tokenEnv is the name of an environment variable, not the value: the key reaches the server through its environment. Put it in the shell that starts the server, or in a .env in the directory it is started from — and if you write a .env, check it is gitignored before you do. If the user pastes a key at you, tell them where it goes; do not store it anywhere yourself.
• Keep maxOutputTokens at 16000 or above. A thinking model given less spends the whole budget thinking and returns empty visible text, which reads as a hung session.
• models is REQUIRED under any id other than openrouter. Every preset in common/modelPresets.ts carries provider: "openrouter", and they are matched by that id — so a backend registered as deepseek, moonshot or a company gateway starts with no models at all, and a provider with no models is not offered in the picker (it cannot start a session either: naming a provider without a model is refused at spawn). Ask which model ids the user wants to run and list them.
• Under the id openrouter, do not write a models array unless the user names a model outside the built-in list — every preset appears in the picker on its own, with its measured pass rate, and models there exists only to ADD ids nobody has measured.
• A model id is letters, digits and . _ : / - ~, optionally ending in [1m]. Anything else in models — an object like {"id": "…"}, a value with a space, a models that is not an array — is dropped when the config loads, leaving a backend that lists models in the file and offers none in the picker. The server log names what it dropped; check it after writing.
• [1m] is Claude Code's extended-context syntax, and the only bracketed suffix there is. It goes to claude --model verbatim — Claude Code strips it before the id reaches the backend, so nothing on this side interprets it. Valid on an alias or a full name (opus[1m], opusplan[1m], claude-opus-5[1m]), refused anywhere but the end, and refused in invented forms like [2m] or [200k]. A provider id may not carry it. Only suggest it when the user asks for the 1M window: on Opus 5 / Sonnet 5 the Anthropic API already runs 1M, so it changes nothing there — the models it decides for are Opus 4.6 / 4.8 and Sonnet 4.6, and a gateway serving Sonnet 5. https://code.claude.com/docs/en/model-config#extended-context
• This is a partial POST /api/config merge — write only providers. Send the array complete (existing entries included): it replaces rather than appends.
• The server reads the environment at startup: after adding a key, it has to be restarted.