live-token-meter — live TPS in the OpenCode 2.0 prompt footer

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
└────────────────────────────────────────────────────────────┘

Requirements

• OpenCode 2.0 beta (opencode2) — the TUI plugin API is beta and pinned to @opencode-ai/plugin@0.0.0-next-17055.
• Bun ≥ 1.0 (only needed to build from source, not to use the plugin).

Install

From npm (recommended)

OpenCode 2.0 automatically installs npm plugin packages into an isolated cache. Add the package to your config — the opencode2 TUI reads ~/.config/opencode/cli.json (the legacy tui.json is migrated into it once, on first start):

// ~/.config/opencode/cli.json
{
  "plugins": [
    {
      "package": "live-token-meter",
      "options": { "charsPerToken": 4, "showTotals": true },
    },
  ],
}

Or as a bare specifier, which is also what a string entry means in opencode.json(c):

{
  "plugins": ["live-token-meter"],
}

You can pin a version:

{
  "plugins": ["live-token-meter@0.1.0"],
}

Restart opencode2 and start a prompt — the footer below the input shows the live readout next to the context indicator.

From source (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/live-token-meter/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.

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.

Development

bun install
bun run typecheck   # tsc --noEmit
bun run test        # bun:test unit + wiring + loader tests
bun run build       # bundle the TUI plugin into dist/ (what gets published)

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.

Publishing

bun run prepublishOnly   # typecheck + build + test
npm publish

The package manifest follows the plugin packaging contract:

• exports["."] and exports["./tui"] both resolve to the bundled dist/tui.js — the host loads the TUI entry directly, no TSX at runtime.
• oc-plugin: ["tui"] marks the package as a TUI plugin.
• @opencode-ai/plugin and @opentui/solid are runtime dependencies so the isolated plugin cache can resolve the imports the bundle keeps external.

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.

License

MIT