Q: How to get the opencode go's model id when create custom subagent ? #56

Hey @dengyakui. Good question, and the short answer is the format here is not the same as the OpenCode Go CLI.

Model ID format

Every model this extension registers follows one shape:

{vendor}:{rawModelId}::{tag}

For your case, that becomes:

That suffix ::session-2026年05月21日-b you saw in your settings key is not part of the model name. It is a metadata revision tag this extension appends so VS Code can invalidate cached picker metadata (token limits, modality flags, etc.) whenever we ship a correction. The ::agent-host suffix marks the agent-window variant, the one that carries targetChatSessionType: "copilotcli" and shows up in the Agents window.

The raw ID in the middle, deepseek-v4-flash, is what actually gets sent to the OpenCode gateway. Same identifier the CLI uses, minus the opencode-go/ prefix.

Getting the full list

The CLI-style format (opencode-go/...) won't work here, because VS Code's Language Model Chat Provider API expects the {vendor}:{id} shape above. Rather than hand-maintain a list, the extension ships a command that dumps every registered model live:

1. Command Palette (Cmd/Ctrl+Shift+P)
2. Run OpenCode: Model Picker Diagnostics
3. A Markdown report opens listing every registered model: id, family, version, vendor, detail, and the configuration schema, for opencodego, opencodezen, the two -agent variants, and Copilot's own models.

You copy the id straight from there. Worth running it periodically too, since Zen rotates free models.

Using it in a custom agent

Here's where it diverges from the CLI. VS Code Copilot custom agents (.chatmode.md, .agent.md) do not take a model ID in the frontmatter the way OpenCode CLI's agents config does. The model is selected at runtime, from the chat or Agents-window picker, and your custom agent inherits whatever OpenCode model is currently selected. So you don't typically hardcode opencodego:deepseek-v4-flash::session-2026年05月21日-b into the agent file.

If you want a specific agent to always run on a specific OpenCode model, the practical workflow:

1. Add the model once via Copilot Chat, model picker, Add Models.... That's what populates the config JSON you pasted.
2. Select that model in the picker before invoking the agent.
3. For Agents-window / Copilot CLI sessions, pick the ...::agent-host variant from the Copilot section of the picker (the opencodego-agent / opencodezen-agent vendors).

The reasoningEffort key in your settings JSON is the per-model Thinking override. Values differ per family: max for DeepSeek, low|medium|high for most openai-compatible families, thinking_budget for Qwen. Those are covered in the README under Reasoning controls.

One caveat

The ::session-2026年05月21日-b tag bumps when we ship a metadata correction, like a context-window fix. The raw ID (deepseek-v4-flash) stays stable. So if you pin a full ID somewhere and it stops resolving after an extension update, re-run Model Picker Diagnostics and grab the fresh one.

Anything unclear, ping back.