opencode-plugin-snip

opencode-plugin-snip is an OpenCode plugin that reduces prompt size before messages are sent to the LLM, then shows the saved-character total live in the TUI.

It is built around one constraint: compression must be deterministic. The same input history should compress the same way every time, so you get smaller prompts without introducing cache-hostile randomness or paying for an extra model pass.

Quick start

Install:

opencode plugin opencode-plugin-snip --global

Install only for the current directory:

opencode plugin opencode-plugin-snip

Public package and source:

• npm: opencode-plugin-snip
• GitHub: https://github.com/disrei/opencode-plugin-snip
• Release: https://github.com/disrei/opencode-plugin-snip/releases/tag/v0.1.0

What you get immediately:

• Deterministic prompt compression before LLM submission.
• A live snip indicator in the OpenCode TUI.
• Per-session saved-character tracking that starts from 0.0k in every new session.

Why this plugin stands out

• Deterministic compression. No LLM rewriting step, no probabilistic summarization, no drifting history.
• Zero extra model cost. Compression is done with fixed rules over message parts and text.
• Session-scoped savings. Every session tracks its own saved-character total and starts from 0.0k.
• Live TUI feedback. The current mode and cumulative savings are visible in the prompt row.
• Tool-aware cleanup. Tool payloads are normalized instead of blindly dumped back into history.
• Protected-block safe. <system-reminder>...</system-reminder> blocks are preserved.
• Three compression levels. Choose pro, max, or max++ depending on how aggressive you want to be.

Features

• Removes framework control events such as [step-start], [step-finish], and [reasoning] when they appear in framework-event form.
• Preserves non-framework user text that merely contains similar markers.
• Preserves <system-reminder>...</system-reminder> blocks.
• Normalizes tool output in max and max++ modes.
• Truncates oversized tool output in max++ mode.
• Tracks saved characters per session, not globally.
• Adds a bright yellow snip label to home_prompt_right and session_prompt_right.
• Keeps optional request logging off by default.

What you see

In the TUI, the plugin shows a label like this:

snip max 12.4k

Meaning:

• snip is the plugin label.
• max is the active compression mode.
• 12.4k is the cumulative characters saved for the current session only.

Install

Install from npm through OpenCode:

opencode plugin opencode-plugin-snip --global

If you want to install only for the current directory, use:

opencode plugin opencode-plugin-snip

OpenCode detects the plugin package from these exports:

• exports["./server"]
• exports["./tui"]

After install, OpenCode patches the relevant config files for you.

Important: local vs global install

opencode plugin opencode-plugin-snip does not write to the global config by default.

Default behavior:

• Local install writes to <current-directory>/.opencode/opencode.json
• Local install writes to <current-directory>/.opencode/tui.json

For example, if you run the command from C:\Users\Disrei, OpenCode may write to:

• C:\Users\Disrei\.opencode\opencode.json
• C:\Users\Disrei\.opencode\tui.json

If you want the plugin in the real global OpenCode config, use --global. That writes to your user config directory instead, such as:

• ~/.config/opencode/opencode.json
• ~/.config/opencode/tui.json

Using plain npm install opencode-plugin-snip is not enough. The package must be installed through opencode plugin ... so OpenCode can patch the config files.

Configuration

After install, OpenCode writes plugin entries into opencode.json and tui.json.

The server plugin supports these options:

{
  "mode": "max",
  "logEnabled": false,
  "logPath": "C:/path/to/opencode-llm.log",
  "toolMaxLines": 40,
  "toolMaxChars": 4000
}

logEnabled defaults to false.

Modes

pro

• Smallest behavior change.
• Best when you want conservative cleanup.
• Keeps tool payloads mostly intact.

max

• Default mode.
• Removes framework noise.
• Normalizes tool payloads.
• Best general-purpose setting.

max++

• Same as max, plus truncates tool output using toolMaxLines and toolMaxChars.
• Best when tool output is the main source of prompt bloat.

TUI behavior

• The mode label comes from the server plugin config.
• The number is the cumulative saved characters for the current session only.
• A brand-new session starts at 0.0k.
• The home screen shows 0.0k because savings are session-based.

Files written by the plugin

The plugin writes per-user runtime data under the OpenCode config directory:

• ~/.config/opencode/snip-stats.json

Optional log output defaults to:

• ~/opencode-llm.log

How it works

Server side:

• Hooks experimental.chat.system.transform
• Hooks experimental.chat.messages.transform
• Compresses message parts deterministically.
• Removes control-event parts and matching framework-event text lines.
• Rewrites tool payloads into a smaller, stable format.
• Updates per-session saved-character stats.

TUI side:

• Registers home_prompt_right.
• Registers session_prompt_right.
• Polls the stats file and renders live saved-character counts.

Local development

You can also use this package source directly as a local plugin during development.

Replace /absolute/path/to/opencode-plugin-snip with your own local checkout path.

Example opencode.json:

{
  "plugin": [
    [
      "/absolute/path/to/opencode-plugin-snip/src/server.js",
      {
        "mode": "max",
        "logEnabled": false,
        "toolMaxLines": 40,
        "toolMaxChars": 4000
      }
    ]
  ]
}

Example tui.json:

{
  "$schema": "https://opencode.ai/tui.json",
  "plugin": [
    "/absolute/path/to/opencode-plugin-snip/src/tui.tsx"
  ]
}

Publish to GitHub

This directory is ready to become a GitHub repository.

Typical steps:

git init
git add .
git commit -m "Initial plugin package"
gh repo create opencode-plugin-snip --public --source . --remote origin --push

Publish to npm

After the GitHub repo is ready and the package name is available:

npm publish --access public

If the package name is already taken, rename the name field in package.json first.

Notes

• Do not publish your personal opencode.json with provider credentials.
• This package only contains the plugin code and documentation.
• The stats file is intentionally session-scoped so session totals do not bleed into each other.