Companion

Companion is an open-source, MIT-licensed tool by The Vibe Company that lets developers go from "I need several specialized agents" to a running fleet they can actually use. Each agent in a fleet gets its own role, tools, memory, runtime, and private access. The project is hosted on GitHub under The-Vibe-Company organization and is available as a compiled Go binary for Linux and macOS.

What It Is

Companion is a CLI-driven agent fleet manager. It treats a local folder as the source of truth — a set of TOML files describing providers, agents, vaults, networking, and identity — and compiles that desired state into typed resources, compares it with observed provider state, and applies changes idempotently. The result is a reproducible, copyable workspace that can be adapted per client, team, or use case without rebuilding the ops stack from scratch.

How the Fleet Model Works

A Companion workspace defines one or more named agents, each with its own:

• Identity — a SOUL.md file that sets the agent's persona and memory policy
• Model — routed through OpenRouter with optional catalog validation
• Runtime — deployed as a Fly.io app with a persistent volume and secrets bundle
• Memory — Granite vaults for durable, cross-agent shared memory
• Private networking — reachable only through Tailscale VPN, not the public internet
• Chat surface — Open WebUI connected to enabled Hermes API servers in the fleet

The CLI loop is: edit TOML → companion validate → companion plan → companion apply.

Architecture and Toolchain

Companion is written in Go. The binary embeds the status dashboard UI (go:embed), so there is no separate frontend build step. State is stored in a local SQLite file (.companion/state.sqlite) as evidence, not desired config. Resource addresses are deterministic (e.g., fly_app.agent.<id>), making plans readable and repeatable. Provider e2e tests use local httptest.Server mocks for Fly, Tailscale, and OpenRouter.

Key infrastructure integrations:

• Fly.io — agent app deployment, volumes, secrets, rollouts
• Tailscale — private mesh networking and hostname drift checks
• OpenRouter — model routing and provider references
• Granite — durable vault memory with MCP read/write roles
• Open WebUI — shared chat frontend backed by fleet API servers

Deployment Model

Companion supports three deployment patterns: a local CLI against a workspace directory, a remote control plane (a persistent Fly app running companion console with a mounted volume), and a deployed dashboard (a stateless Fly app reachable only over Tailscale). The control plane tracks multiple workspaces in ~/.companion/workspaces.json and supports upgrade, export, and status commands. Secrets are read from .env or the shell environment; Companion prints secret names only, never secret values.

Update: v0.2.0

The latest release is v0.2.0, published in June 2026. The GitHub README notes that the previous Companion web UI codebase has been archived at archived/legacy-companion/, and Companion is now the Go control plane described in the current README. Release Please manages version PRs, changelog updates, tags, and GitHub Releases; release assets contain a single companion binary for Linux and macOS. The repository has accumulated over 2,300 stars and nearly 300 forks since its creation in early 2026, according to GitHub metadata.