What
An interactive, multi-step wizard for configuring Google Vertex AI as your model backend, with credential validation and model pinning.
Details
- Step-by-step flow: authentication method → service account key (if applicable) → GCP project → region → credential verification → model pinning → confirmation
- Three authentication methods: Application Default Credentials (gcloud auth), service account key file, or existing environment credentials
- Reads existing gcloud configurations to auto-discover project IDs
- Validates credentials by making a test API call to Vertex AI
- Probes each model tier (Sonnet, Opus, Haiku) with a one-token request to check availability
- Provides specific error messages for common issues: expired credentials, missing permissions, wrong region, missing API enablement
- Model pinning option: pin specific model versions that are confirmed working, or use Claude Code defaults (auto-updates)
- Saves configuration to
~/.claude/settings.jsonunder theenvkey - For ADC users, reminds that
gcloud auth application-default loginrefreshes credentials automatically
Evidence
Vertex setup wizard (search for "How do you authenticate to Google Cloud?" and "Pin model versions")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agree
Fixed permission rules with names matching JavaScript prototype properties (e.g. toString) causing settings.json to be silently ignored