opencode-tui-usage

A single OpenCode TUI sidebar plugin that unifies prompt-cache, token, cost, context, tools, skills, speed and sub-agent usage into one coherent panel. English and USD only. Precision first: anything that cannot be grounded in API-reported data is clearly flagged as an estimate (est. / ~est) and never contributes to a precise total.

It merges and replaces the overlapping functionality of opencode-cache-hit (modular architecture, sub-agent rollup, cache TTL, JSONL timeline) and opencode-visual-cache (persisted fold state, estimated role distribution, loaded-skills detection).

Install

You can install the plugin either globally (for all TUI sessions) or locally (on a per-project basis).

Global Installation

To enable the plugin globally across all your projects, add it to your global TUI configuration file at ~/.config/opencode/tui.json:

{
  "plugin": ["opencode-tui-usage@latest"]
}

Per-Project Installation

To enable the plugin only for a specific project, create or modify the local TUI configuration file at .opencode/tui.json in your project's root directory:

{
  "plugin": ["opencode-tui-usage@latest"]
}

Start OpenCode and open the TUI sidebar; the panel registers automatically and appears once the session has usage data.

Panel layout

One collapsible panel with eight independently collapsible sections. The organizing principle is cumulative (lifetime) data is separate from current (context-window) data, which also resolves undo/fork semantics cleanly.

| # | Section | What it shows | Precision | | --- | ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------- | | 1 | Cache | last-turn Hit% bar + trend; session Total Hit; cache TTL age (color-coded) | precise | | 2 | Context | precise Fill used / limit (pct%); compaction indicator; estimated role breakdown (System / User / Tool calls / Tool out / Reasoning / Other) | fill + compaction precise; breakdown est. | | 3 | Session | cumulative Input (Miss) / Output / C.Read / C.Write / Reason; cumulative Cost + Last-turn cost; cache Saved $ | precise | | 4 | Model | provider, model, pricing ($/M in, /M cache, /M out); >200K tiered-pricing indicator; click to open the model picker | precise | | 5 | Tools | per-tool call counts | precise | | 6 | Skills | loaded skill names + load counts + ~est token footprint | names/counts precise; tokens estimate | | 7 | Speed | Now / Last / Avg tok/s, trend sparkline, TTFT | precise-ish (from part timestamps) | | 8 | Agents | sub-agent rollup (aggregate tokens + cost) + per-agent rows; click a row to open that sub-agent's session | precise |

When the whole panel is collapsed, the title row shows the last-turn Hit% (or total sub-agent cost when there is no main session data yet).

Interactive elements

Some rows respond to the mouse (they highlight on hover):

• Model (§4): click to open the model picker (the same dialog as the /models slash command), so you can switch the active model without leaving the panel. After you switch, the displayed model updates once the switch is recorded — opencode does not expose the picker's pre-submit selection to plugins, so it cannot update before you send a query.
• Agents (§8): click a sub-agent row to open that sub-agent's session and read its log.

Token terminology

Each assistant turn reports tokens: { input, output, reasoning, cache: { read, write } }:

• C.Read = cache.read — prompt tokens served from cache (cheap).
• Input (Miss) = input — fresh prompt tokens billed at full input price.
• C.Write = cache.write — tokens written into the cache this turn.
• Output = output; Reason = reasoning.
• Hit % = read / (read + input).

Context role breakdown

Under Section 2 (Context), the plugin estimates the breakdown of tokens occupied by different roles in the active context window:

• System: System instructions, core agent guidelines, and tool definitions.
• User: User queries, instructions, and uploaded files / workspace context.
• Tool calls: Raw inputs and parameters sent to tools.
• Tool out: Outputs, results, or errors returned from executed tools.
• Reasoning: Internal reasoning / chain-of-thought tokens generated by reasoning models (e.g., DeepSeek R1, OpenAI o1/o3).
• Other: Spawned sub-agent workspace tasks, along with formatting wrappers, metadata, and estimation variance.

Note: Individual categories are calculated using character-to-token heuristic estimators (labeled as est.), while the overall context fill total is 100% precise. To keep the UI clean, any category occupying less than 0.05% of the total context is automatically hidden.

Configuration

Two distinct mechanisms:

• Fold / collapse state is persisted via api.kv and survives restarts. No config needed — just expand/collapse sections in the TUI.
• Everything else is a JSON config file. Preferred path: ~/.config/opencode/opencode-tui-usage.json (survives plugin updates); fallback: plugin-root opencode-tui-usage.config.json. Edits are picked up when the parent session changes (no full reload required).

Section visibility (whether a section is rendered at all) is controlled by display.sections.* in the config; section fold (expanded vs collapsed) is the kv-persisted state. The two are independent.

See opencode-tui-usage.config.example.json for all options:

{
  "display": {
    "panelBorder": true,
    "contextBreakdownEstimate": true, // §2 estimated role breakdown (default on)
    "contextBreakdownTokens": false, // If true, shows raw token values instead of percentages (default false)
    "sections": {
      // section visibility (not fold state)
      "cache": true,
      "context": true,
      "usage": true,
      "model": true,
      "tools": true,
      "skills": true,
      "speed": true,
      "agents": true,
    },
  },
  "cost": { "decimals": 4, "minDisplay": 0.0001 }, // USD only
  "cacheTTL": {
    "enabled": true,
    "providers": {
      "anthropic": "5m",
      "openai": "5m",
      "deepseek": "2h",
      "google": "1h",
    },
  },
  "timeline": {
    // opt-in JSONL export, OFF by default
    "enabled": false,
    "dir": "",
    "rotateMaxBytes": 16777216,
    "retainRotated": 5,
    "maxAgeDays": 30,
    "maxLogFiles": 20,
    "toolSummary": { "allTools": true, "bash": false },
  },
}

Notes:

• Cache TTL colors: green while elapsed < TTL, yellow TTL ≤ elapsed < 2×, red ≥ 2×. Built-in default 5m; per-provider overrides parse durations like 30s, 5m, 1.5h, 2h. A unitless value is interpreted as seconds (e.g. "300" = 5 minutes).
• Timeline JSONL export is secure-by-default (toolSummary.bash: false) — bash inputs may leak credentials and are only truncated, not sanitized.
• Tiered pricing: when the current context exceeds 200K tokens and the model exposes experimentalOver200K pricing, displayed rates and the savings estimate switch to the tiered rates (the reported cost is already correct regardless).

Undo / revert / fork

• Context fill (§2) and last-turn Hit% (§1) read the live message list, so /undo, revert-to-point and fork are reflected automatically — context fill shrinks when history is rolled back.
• Session usage and cumulative cost (§3) read DB aggregates, which are cumulative and do not roll back — correct, because spend is not refunded.
• Forks appear as separate session ids; child-session sync keys off parentID, so a fork surfaces as its own session rather than corrupting the parent totals.

Development

bun install
bun test        # run the test suite
bunx tsc --noEmit   # typecheck

Credits & license

MIT. Derived from the MIT-licensed opencode-cache-hit by zhumengzhu and opencode-visual-cache by Hotakus. The cache-TTL display is inspired by opencode-cache-timer by nero-sensei.