Use a local command-line agent
Keep the agent you already use. Install and authenticate it first, then let OpenDesign discover its executable.
Install and sign in
Open Settings → Models & providers → Local CLI. Expand Available CLIs and use Install or View docs for the agent you want. Complete installation and authentication in that agent's own setup flow. An installed binary and an authenticated account are different prerequisites. A successful scan does not sign you in.
Rescan and select
Return to OpenDesign and click Rescan. Choose the agent under Installed CLIs, then select its available model. CLI default means the model is inherited from the agent's own configuration.
When the agent is missing
Check that the executable works outside OpenDesign and that the app's background process can find it. A command available only through an interactive shell alias may not be available to the desktop app. After correcting the installation path, rescan again.
When authentication is required
Finish login or credential configuration in the agent itself. Return to OpenDesign after authentication completes. Do not paste a provider key into an unrelated Cloud account field to resolve a CLI login error.
Custom endpoints and multiple accounts
Use the client's supported custom-agent settings and the agent's own documentation. Keep executable paths, endpoint addresses, model names, and account configuration together. A model preset alone does not create a running local service. Before sharing logs or commands, remove tokens and private machine paths. For externally controlled workflows, see OpenDesign MCP.
Compatibility and reasoning effort
Where supported by a local agent such as Codex, OpenCode or DeepSeek Harness, reasoning effort can be selected in the model picker. Available levels depend on the agent, model and provider. The hosted-model panel does not currently offer the same control; accepting a parameter in an external API does not imply a toggle exists in the app.
Current support guidance flags OpenCode v2 as not yet integrated; check version compatibility after a major-version upgrade. Antigravity also has a known Windows launch issue with long prompts. Update first; if it persists, switch to another working agent and export diagnostics with reproduction details.