Canonical page: https://model-orchestrator.aunysillyme.dev/docs/companions/
Source: https://github.com/aunysillyme/model-orchestrator/blob/205760296bb61082960552986181bfb3b9fa6196/docs/companions.md
Relative links in the source below resolve against that repository source location.

---

# Works well with

Companions add calculation, searchable notes or current library documentation. They are other authors' projects, with their own releases and support channels. All are opt-in; a default install and `--yes` both select none.

```bash
npx model-orchestrator --tools codecalc,obsidian-tc,context7
```

Selecting a companion writes model-orchestrator's setup guide and configuration snippets. With automatic activation enabled, a Claude Code main agent also gets the selected servers merged into the project's `.mcp.json`. The summary names this file before the single confirmation; an existing file gets a backup, and existing server entries stay intact. Other hosts keep a manual registration step when the catalog has no verified project-scoped config. `--no-apply` leaves registration manual; `--yes` applies it only with `--apply-snippets`.

The installer writes its managed files and the project configuration changes named in the summary, prints missing tools together under **Install these yourself**, and leaves third-party commands for you to run. It never edits global user config. codecalc still needs uv and Python 3.10+; obsidian-tc still needs your vault configuration path. Context7's hosted connection needs no local package install. `--no-tools` remains accepted for existing scripts.

## Choose a companion

| Project | Maintainer | What it adds | Setup and support |
|---|---|---|---|
| [codecalc](https://github.com/The-40-Thieves/codecalc) | The-40-Thieves | Local arithmetic, code execution, logic and equivalence checks | Follow the generated `CODECALC.md` and the [upstream instructions](https://github.com/The-40-Thieves/codecalc#readme); report tool issues [upstream](https://github.com/The-40-Thieves/codecalc/issues) |
| [obsidian-tc](https://github.com/The-40-Thieves/obsidian-tc) | The-40-Thieves | Search, backlinks and controlled writes for an Obsidian notes folder | Follow `OBSIDIAN-TC.md` and the [upstream instructions](https://github.com/The-40-Thieves/obsidian-tc#readme); report tool issues [upstream](https://github.com/The-40-Thieves/obsidian-tc/issues) |
| [Context7](https://github.com/upstash/context7) | Upstash | Current documentation and examples for a specific library version | Follow `CONTEXT7.md` and the [upstream instructions](https://github.com/upstash/context7#readme); report tool issues [upstream](https://github.com/upstash/context7/issues) |

Check each project's current runtime and sign-in requirements before installing it. Context7 sends documentation queries over the network, including when its MCP server runs locally. Keep private source and secrets out of query text.

## Use the protocols with your existing tools

| Need | With a companion | With your existing tools |
|---|---|---|
| Compute and verify | codecalc | A calculator, a local runtime or your project's test command |
| Search and record | obsidian-tc | A notes folder, file search and version control |
| Check an API | Context7 | Current official documentation and upstream source, then a local execution check |

Every install includes `protocols/numbers-and-logic.md`, `protocols/memory-and-record.md` and `protocols/docs-then-prove.md`. The protocols describe the job; companion selection changes which tool can do it.

## Keep an existing setup

Upgrading from 0.1.x preserves existing codecalc files. `--uninstall` removes a managed companion guide or snippet only when its content still matches the recorded hash; edited files stay and are listed. Automatically merged project MCP entries are recorded separately: uninstall removes only entries the installer added that still match their recorded configuration. Other servers, user edits and backups stay. See [Upgrading from 0.1.x](install.md#upgrading-from-01x).