OpenCode mini session

An OpenCode TUI plugin that opens an interactive mini temporary session for side questions, with full session context and multi-turn conversation.

https://github.com/user-attachments/assets/8201b065-2569-41ba-8eb7-ac2abddad2a5

What it does

Press alt+b (or run /mini from the command palette) during any OpenCode session. A popup overlay opens immediately with a text input at the bottom. Type a question and press Enter to send it. The plugin:

1. Gathers context from the current session (token-limited)
2. Creates a temporary isolated session with that context
3. Sends your question to the AI and streams the response
4. Lets you ask follow-up questions in the same mini session
5. Optionally injects the full mini-session transcript back into the main thread
6. Deletes the ephemeral session on close

Keybinds

Trigger

| Key | Action | |---|---| | alt+b (configurable) | Toggle mini session overlay | | /mini | Open mini session (command palette) | | /mini-model | Change model for future mini sessions |

Inside the mini session

| Key | Action | |---|---| | enter | Send question / follow-up | | alt+b (configurable) | Hide overlay (resumable) | | tab | Change the model for the next question | | esc / ctrl+c | Cancel and close |

Installation

Add to your OpenCode TUI config (~/.config/opencode/tui.json):

{
  "plugin": [
    ["opencode-mini-session", {
      "model": "some-provider/your-model",
      "tokenLimit": 50000,
      "keybind": "alt+b",
      "allowedTools": ["glob", "grep", "read", "list", "webfetch"]
    }]
  ]
}

OpenCode installs it automatically with Bun on startup.

Configuration

All options are optional. Defaults are shown below.

| Option | Type | Default | Description | |---|---|---|---| | model | string \| null | null | Override model as providerID/modelID (e.g. "anthropic/claude-sonnet-4-5"). null auto-detects from current session. | | tokenLimit | number | 50000 | Maximum tokens of session context to include. | | keybind | string \| false | "alt+b" | Global keybind. Set to false or "none" to disable. | | allowedTools | string[] \| null | null | Tools the mini session agent can use. See Tool access. |

Tool access

By default the mini session has access to read-only tools: glob, grep, list, read, webfetch. Use the allowedTools config option to change this:

• null or omitted: use the default tools listed above
• []: disable all tools
• ["bash", "edit", "read"]: only the listed tools
• ["*"]: enable all available tools

To see available tool names, run opencode debug agent general and check the tools object in the output.

Session context

The mini session receives the main session's conversation as plain text:

• User questions
• Assistant responses
• Tool calls summarized inline (name + up to 4 input params, e.g. [tool: read path=src/foo.ts])

Oldest messages are dropped to fit the tokenLimit, and the result is injected into the system prompt inside <session-context> tags.