Live Token Meter

A TUI plugin for the OpenCode 2.0 CLI that shows live tokens-per-second in the footer line below the input, right beside the context indicator.

While the model streams, the footer shows a live estimate; when the step finishes, it shows the exact average from the provider's token accounting.

┌────────────────────────────────────────────────────────────┐
│ ...                                         30.5K (3%)     │
│  33.3 tok/s · total 15k tok                  ctrl+p ...    │   ← streaming
│                                                             │
│ ...                                         30.5K (3%)     │
│  ✓ 200 tok/s · 15k tok · total 15k tok       ctrl+p ...    │   ← last step
└────────────────────────────────────────────────────────────┘

How it works

Built against the OpenCode 2.0 TUI plugin API (@opencode-ai/plugin/tui, define({ id, setup })):

• Registers the prompt.footer.end slot (the footer line below the input, next to the context indicator) via context.ui.slot.
• Subscribes to the server event stream with context.data.on:
  • session.step.started — start the timing window
  • session.text.delta / session.reasoning.delta — live estimate from character deltas (chars / charsPerToken, default 4)
  • session.step.ended — exact tokens.output + tokens.reasoning divided by the step duration
  • session.step.failed — error state
• Per-session reactive state lives in a solid-js store via context.storage.memory, so the slot re-renders on every delta.
• The session-wide token total is summed from context.data.session.message.list.

Install

The opencode2 TUI reads ~/.config/opencode/cli.json (the legacy tui.json is migrated into it once, on first start). Add a plugins entry:

{
  "plugins": [
    { "package": "tps-oc2", "options": { "charsPerToken": 4, "showTotals": true } }
  ]
}

For local development, point package at the entry file — the TUI host resolves file plugins as plain paths (no exports map), so give it a file, not a directory:

{
  "plugins": [
    { "package": "/absolute/path/to/tps-oc2/src/index.tsx", "options": { "charsPerToken": 4 } }
  ]
}

A directory spec is also supported if the repo provides a tui/ entry point (one is shipped at tui/index.ts).

Options

Option	Default	Description
enabled	true	Set to false to disable the plugin.
charsPerToken	4	Chars per token for the live estimate. Tune per provider (Anthropic ≈ 4, OpenAI ≈ 4.2).
showTotals	true	Show the session-wide cumulative token count.

Development

bun install
bun run typecheck   # tsc --noEmit
bun test            # bun:test unit + wiring + loader tests

To test against a live TUI: add the plugin to cli.json (see Install), open a session, and start a prompt — the footer below the input shows the live readout next to the context indicator.

Notes

• The live value is an estimate (chars / charsPerToken); the settled value after each step is exact (provider usage accounting).
• Each open session is tracked independently via its sessionID.
• Pinned to the @opencode-ai/plugin@0.0.0-next-17055 API (matches the opencode2 next binary). The TUI plugin API is beta and may change — bump the pinned versions when you upgrade opencode2.