Buddy

A virtual ASCII pet companion that lives in the opencode TUI sidebar. One buddy per opencode session — switch sessions and you meet a different buddy; reopen the same session later and yours is exactly as you left it. Hatches, grows, and earns xp from your actual coding — every tool call, every completed turn, every approved permission feeds the buddy.

┌──────────────────────────┐
│  opencode TUI            │
│                          │
│  > your prompt here      │
│                          │
│         sidebar          │
│ ┌──────────────────────┐ │
│ │ Quack the duck       │ │
│ │       __             │ │
│ │     <(o )___         │ │
│ │      ( ._> /         │ │
│ │       `--'           │ │
│ │ ──────────────────── │ │
│ │ hunger ████████░░ 79 │ │
│ │ happy  ████████░░ 79 │ │
│ │ energy ██████████ 100│ │
│ │ idle · Lv 1 · xp 0   │ │
│ └──────────────────────┘ │
└──────────────────────────┘

Since v0.5.0 the buddy is work-driven: xp comes from the LLM calling tools, finishing turns, and you approving permissions — not from slash commands. Slash commands stay around for "I want to feed my pet right now" interactions. The buddy gets tired when you push it hard, naps to recover when you walk away, and slows down late at night.

Since v0.6.0 the buddy is per-session: each opencode session has its own state file at ~/.config/opencode-buddy/sessions/<sessionID>.json, so multiple windows and projects never share or fight over a buddy. Sessions idle for 30+ days are automatically deleted by a daily LRU sweep.

Install

Requires opencode ≥ 1.15.

npm install -g opencode-buddy

The postinstall script automatically registers the plugin in both config files using the same spec. opencode picks the right entrypoint from the package's exports field based on runtime kind:

• opencode.json (kind: server) → src/server-plugin.js via main (no-op since 0.3.x)
• tui.json (kind: tui) → src/tui-plugin.jsx via exports["./tui"]

Both ~/.config/opencode/opencode.json and ~/.config/opencode/tui.json get the same plugin: ["opencode-buddy"] entry. The postinstall is JSONC-safe — it leaves any file that contains comments alone and asks you to add the entry manually:

// ~/.config/opencode/opencode.json
{
  "plugin": ["opencode-buddy"]
}

// ~/.config/opencode/tui.json
{
  "$schema": "https://opencode.ai/tui.json",
  "plugin": ["opencode-buddy"]
}

Restart opencode. The buddy appears in the sidebar.

Usage

Slash commands

Type / in the prompt to see the slash commands. The buddy ships with seven:

Slash command	Effect
/buddy	Show the current session buddy's stats as a toast
/buddy-feed	Feed the buddy (+25 hunger, -5 energy)
/buddy-play	Play with the buddy (+15 happiness, +1 xp, -10 energy, -5 hunger)
/buddy-rest	Let the buddy rest (+30 energy)
/buddy-list	List every active session's buddy (name, species, level)
/buddy-rename	Open a prompt to rename the buddy (max 20 chars)
/buddy-switch	Open a picker to switch to duck, cat, dragon, axolotl, robot, or ghost

/buddy-play only gives +1 xp — meaningful xp comes from coding (see below). All slash commands except /buddy-list target the current opencode session's buddy (read from api.route.current.params.sessionID).

Automatic reactions (work-driven xp & rewards)

The buddy listens to opencode's live session events. Every event tweaks the buddy's stats so the sidebar actually drifts in response to what you're doing:

Trigger	Effect
Prompt submitted	enter working state, mark lastPromptAt
Tool call succeeds	+xp per tool (read=1, edit/write/bash=3, others=2), +0.2 happy
3 consecutive tool successes (no failure)	+5 xp streak bonus
Same tool used >5 times in one turn	xp halved for that tool (anti-grind)
Tool call fails	-1 happy, -0.5 energy, streak reset; 2+ fails → scared
Todo marked completed	+5 xp per item
File edited (file.edited)	+1 hunger (30s global throttle)
Shell command finished	+1 hunger, +1 energy
Permission granted (once/always)	+3 hunger, +1 happy
Git branch switched	+3 hunger, +1 happy
Session history compacted	+10 energy, +2 happy
Idle >5 min without a prompt	+5 energy (5 min cooldown)
Turn finished (session.idle)	+10 base xp + accumulated (cap 30/turn), 3s celebrating, toast Turn complete +N xp or Level up!
Session error	5s scared
Level up	+5 hunger, +3 energy, +3 happy

Passive metabolism

Between events the buddy slowly drifts on a natural clock:

Stat	Per minute	Notes
hunger	-0.3	always
happiness	-0.2	always
energy	-0.15 (×1.5 at 23:00–05:00)	drains 1.5× faster late at night
energy (sleeping)	+1.0	the buddy heals itself if you walk away

Hard thresholds:

• Energy < 20 → sleeping (animation pauses; energy recovers passively)
• Hunger < 25 → scared for 30 s

State lives in ~/.config/opencode-buddy/sessions/<sessionID>.json — one file per opencode session. Switch sessions in opencode and the sidebar swaps to the corresponding buddy. Reopen the same session later and the buddy is exactly as you left it.

Per-session storage

~/.config/opencode-buddy/
└── sessions/                      # active buddies
    ├── __default__.json           # fallback for LLM tool calls with no session arg
    ├── abc-123.json               # session "abc-123"
    └── def-456.json               # session "def-456"

• One file per opencode session. 1000 active sessions ≈ 500 KB.
• __default__ is a synthetic session used when no real opencode session is in scope (e.g. the LLM tool without a session argument). Upgrades from v0.4/v0.5 transparently migrate the legacy global state.json into sessions/__default__.json on first read.
• A background timer runs at plugin boot and once a day, deleting any session file whose idleAt is older than 14 days. The buddy is gone for good — no archive folder to clean up later.
• /buddy-list shows the active roster; the current session's buddy is marked with →.

What you see in the sidebar

The sidebar shows the buddy's species-specific ASCII art, plus four lines under it:

[BDDY]  Quack the cat        <- species + name (preceded by a rotating status dot)
<art rows>                     <- 6 rows of the species art
hunger |████░░░░░░| 79         <- hunger bar
happy  |███░░░░░░░| 60         <- happiness bar
energy |███████░░░| 70         <- energy bar
idle  Lv1  xp5/50              <- state label + level + xp progress (xp needed = level * 50)

The bottom state label reflects the persisted state field in the session's file. It changes on session events (celebrating / scared / working) and on energy/hunger thresholds (auto sleeping or scared). The art's idle state has 3 frames; the sidebar re-renders the current frame each time the plugin-level frame signal advances.

Six species

        duck                    cat                  dragon
          __                /\_/\                  /^^\
        <(o )___          ( o.o )                (o o)  ~~
         ( ._> /           > ^ <                  >w<    ~
          `--'            /|   |\                /| |\
       ~ idle ~         (_|   |_)               (_| |_)
                           meow                   rawr

      axolotl                robot                  ghost
       ^___^              [ O . O ]              .-"-"-.
      (o . o)             /|#####|\              ( o . o )
     \|_|_|/             / |#####| \             | ~  ~ |
      \| |/               |     |                |     |
       ) (               /| | | |\               \uuuuu/
     ~ ambien              beep                   boo

Each species has a per-character color palette. The idle state has 3 frames; frameCount is exposed so the View can pick a frame to render. The buddy renders whatever frame frame() % fc() returns at the moment of re-render.

Architecture

flowchart LR
    subgraph User
        U[Opencode TUI user]
    end

    subgraph OpencodeTUI["opencode TUI process (binary)"]
        direction TB
        Config[("tui.json<br/>plugin: [opencode-buddy]")]
        Runtime[TuiPluginRuntime]
        Sidebar[Sidebar component]
        Prompt[Prompt component]
        Slots{{"slot registry<br/>sidebar_content"}}
        Keymap{{"keymap<br/>(slash commands)"}}
        Bus{{"event bus<br/>(session/tool/file/<br/>perm/todo/vcs/...)"}}

        Config --> Runtime
        Runtime --> Slots
        Runtime --> Keymap
        Slots --> Sidebar
        Keymap --> Prompt
    end

    subgraph Buddy["opencode-buddy plugin (jsx)"]
        direction TB
        TUIEntry["tui entry<br/>(id: opencode-buddy)"]
        View[View component<br/>SolidJS]
        FrameSignal[("frame signal<br/>(plugin-level)")]
        AnimTick[setInterval 300ms<br/>frame++ gated by energy]
        RefreshTick[setInterval 1500ms<br/>mtime poll]
        IdleTimer[setInterval 60s<br/>idle-recovery]
        Hooks["event hooks (10+)<br/>prompted / tool.called /<br/>tool.success / tool.failed /<br/>todo / file.edited / perm /<br/>shell / branch / compacted /<br/>idle / error"]
        TurnAccum[("turnAccum<br/>per-session memory<br/>xp · tools · failures ·<br/>streak · toolCounts")]
        SlashCmds["slash commands<br/>feed / play / rest /<br/>status / rename / switch"]

        TUIEntry --> FrameSignal
        TUIEntry --> View
        TUIEntry --> SlashCmds
        TUIEntry --> Hooks
        TUIEntry --> IdleTimer
        FrameSignal --> AnimTick
        View --> RefreshTick
        Hooks <--> TurnAccum
    end

    subgraph State["Persistent state (per session)"]
        direction TB
        StateRoot["~/.config/<br/>opencode-buddy/"]
        SessionsDir["sessions/"]
        Default[("__default__.json")]
        Sess1[("abc-123.json")]
        Sess2[("def-456.json")]

        StateRoot --> SessionsDir
        SessionsDir --> Default
        SessionsDir --> Sess1
        SessionsDir --> Sess2
    end

    U -->|types| Prompt
    Prompt -->|/buddy-feed etc| Keymap
    Keymap --> SlashCmds
    SlashCmds -->|"read+write per session"| SessionsDir
    SlashCmds -->|toast feedback| U

    Slots -->|invokes renderer| View
    View -->|render frame| Sidebar
    View -->|"reads mtime per session"| SessionsDir
    RefreshTick -->|state changed| View
    Bus -->|10+ event types| Hooks
    Hooks -->|"mutate per session"| SessionsDir
    Hooks -->|Level up! / Turn complete toast| U
    IdleTimer -->|"+5 energy per session"| SessionsDir
    AnimTick -->|"reads energy per session"| SessionsDir

    classDef store fill:#1e293b,stroke:#64748b,color:#f1f5f9
    class Default,Sess1,Sess2,TurnAccum store

Boot flow

1. opencode reads ~/.config/opencode/tui.json and discovers the buddy entry under plugin.
2. The TUI runtime loads tui-plugin.jsx from opencode-buddy (via exports["./tui"] in package.json).
3. The tui(api) function runs once. It sets up:
   • A plugin-level frame signal + setInterval (300 ms) that ticks it. The View is passed the signal as a prop, so slot re-renders cannot freeze the animation.
   • The sidebar_content slot. The slot renderer is cached per sessionID so the View instance is reused across re-renders and survives session switching.
   • 7 slash commands on the keymap (including /buddy-list).
   • 10+ event hooks on the session bus (prompted, tool.called/success/failed, todo, file.edited, permission.replied, shell.ended, vcs.branch.updated, session.compacted, session.idle, session.error). Each hook resolves the target sessionID from the event payload (or lastActiveSessionID for events that don't carry one) and mutates that session's file in sessions/, updating the in-memory turnAccum along the way.
   • A 60-second idle-recovery timer that iterates all sessions in sessions/ and grants +5 energy to any whose lastPromptAt is older than 5 min.
   • A daily LRU sweep that deletes session files whose idleAt is older than 14 days.
4. The TUI's <Slot name="sidebar_content" /> resolves to the buddy's cached View (keyed by session_id). The View reads the frame signal and re-renders the buddy art on every tick.
5. The View also runs a 1500 ms timer that polls its own session's file mtime. When the file changes (slash command or event hook wrote to it), the View reloads and re-renders.
6. The animation timer advances unconditionally; per-session sleeping buddies just render the same static frame on every tick (cheap; the renderFrame is pure).
7. On session.idle, the event hook settles the turn atomically for that session: load → apply onTurnDone(state, accumXp, stats) → save. If a level-up happened, a Level up! toast surfaces; otherwise Turn complete +N xp from M tool calls.

Why two config files with the same spec?

opencode has separate plugin registries for the server (LLM tools, file watching) and the TUI (sidebar slots, slash commands, keybindings). When the same package spec appears in both, opencode looks at the package's exports field to pick the right entrypoint:

• opencode.json → kind: "server" → loads src/server-plugin.js via main (no-op since 0.3.x)
• tui.json → kind: "tui" → loads src/tui-plugin.jsx via exports["./tui"]

Slash commands and event hooks update state instantly without round-tripping through the LLM, which is the right UX for both "I want to feed my pet right now" interactions and "the LLM just finished a turn, react now" reactions.

Project layout

opencode-buddy/
├── package.json
├── README.md
├── LICENSE
├── scripts/
│   └── postinstall.mjs     # auto-registers plugin in opencode.json + tui.json
└── src/
    ├── tui-plugin.jsx     # TUI plugin: per-session slot + 7 slash commands + 10+ event hooks
    │                      #   + idle-recovery timer + daily LRU sweep
    ├── server-plugin.js   # Server plugin: LLM tool (accepts session arg) + action=list
    ├── species.js         # ASCII art + per-species palettes + 3-frame idle loop
    ├── state.js           # state machine: tick (night/sleep aware), feed, play, rest,
    │                      #   plus event-driven mutators (onPromptStart, onToolSuccess,
    │                      #   onToolFailure, onTurnDone, onTodoCompleted, onFileEdited,
    │                      #   onPermissionAllowed, onShellSuccess, onBranchUpdated,
    │                      #   onCompacted, onIdleRecovery, onStreak), maybeLevelUp
    └── persistence.js     # per-session load/save/mtime + sweep + listSessions + legacy migration

State lives at ~/.config/opencode-buddy/sessions/<sessionID>.json (one file per opencode session, plus a __default__ synthetic session for LLM tool calls outside a session). ~/.config resolves via os.homedir() so it works on Linux, macOS, and Windows.

Uninstall

npm uninstall -g opencode-buddy

Then remove "opencode-buddy" from opencode.json and from tui.json (the npm uninstall does not auto-edit user config).

License

MIT