opencode-subagent-models

Set one model and reasoning variant for every OpenCode subagent, globally or for one session.

Use a stronger model for a difficult task, move delegated work to a cheaper model, or restore each subagent's configured model. Primary sessions remain unchanged.

Features

• Applies a global provider/model override to delegated subagents.
• Lets one session and its delegated subagents override the global selection.
• Restores each subagent's configured model without rewriting agent files.
• Adds global and session model commands under Agent in the command palette.
• Registers /subagents-model and /subagents-model-session.
• Applies changes to new delegated subagent messages without restarting OpenCode.

Installation

OpenCode loads server and TUI plugins from separate configuration files. Add the same exact package version to both files. OpenCode caches npm plugin specs, so a pinned version avoids reusing an unversioned cache from an older release.

~/.config/opencode/opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["[email protected]"]
}

~/.config/opencode/tui.json:

{
  "$schema": "https://opencode.ai/tui.json",
  "plugin": ["[email protected]"]
}

Close every OpenCode instance, then start it again. OpenCode installs the pinned package on startup.

Usage

Open the command palette and choose Global subagent model or Session subagent model. The matching slash commands are:

/subagents-model
/subagents-model-session

Each model selector keeps Default first, followed by models grouped by provider. After choosing a model, select its reasoning variant. Models without variants show only Default in the second selector.

Global Default restores each subagent's configured model. Session Default stops inheritance from session ancestors and uses the global selection.

The session override applies to subagents delegated from that conversation. Other sessions and terminals keep their own session override or inherit the global selection.

Scope

| Context | Result | | --- | --- | | Delegated subagent | Uses the global override when enabled | | Delegated subagent in an overridden session | Uses the session model and variant | | Primary session | Never changed | | Global Default | Each delegated subagent uses its configured model |

How it works

The global selection is stored in ~/.config/opencode/subagent-model.json. Session selections use one file per session under ~/.config/opencode/subagent-models/; selecting session Default writes a default marker there. For each delegated message, a hook resolves the nearest session override and then the global selection.

The default setting skips the matching override. The plugin does not copy, edit, or back up agent files.

Updating

Change the pinned version in both opencode.json and tui.json, then close every OpenCode instance and reopen it. Keep both files on the same version.

Troubleshooting

If the commands do not appear in Ctrl+P, confirm that the package is present in both configuration files and that both use the same exact version. Then inspect the OpenCode startup log at ~/.local/share/opencode/log/opencode.log for plugin loading errors.

If /subagents-model is sent to the LLM as a prompt, OpenCode loaded a release older than 0.2.0. Pin the current version in both files and restart every OpenCode instance. The exact version creates a separate cache, so manual cache deletion is not required.

Local development

npm install
npm test
npm pack --dry-run

Load a local checkout by adding its directory to the plugin array in both opencode.json and tui.json, so the server and TUI entries resolve:

{
  "plugin": [
    "file:///path/to/opencode-subagent-models"
  ]
}

Requirements

• OpenCode 1.17.18. Other releases work only while they retain the v1 TUI command bridge.
• Node.js ^22.22.2, ^24.15.0, or >=26.0.0 for local development.

Community

This is an open source collaborative project under the MIT License. Bug reports, feature proposals, and pull requests are welcome.

• Read CONTRIBUTING.md before submitting a change.
• Use the issue templates for public bug reports and feature requests.
• Report suspected vulnerabilities through the private channel in SECURITY.md.
• Follow CODE_OF_CONDUCT.md in project spaces.

License

MIT