[docs]: add Google Vertex AI configuration

[shrey150]

Summary

• Adds a Google Vertex tab to the First Class Models section in the v3 models docs
• Documents the experimental: true requirement, model object format (project, location, googleAuthOptions), and service account credentials setup
• Adds Google Vertex to the API key troubleshooting table

This was requested in Discord — the vertex/ provider is fully supported in code but was missing from documentation.

Test plan

• Verify the new tab renders correctly on the docs site
• Confirm code snippet matches the accepted GoogleVertexProviderSettings type

🤖 Generated with Claude Code

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Summary by cubic

Added Google Vertex configuration to v3 models docs. New tab with TS example using vertex/gemini-3-flash-preview, service account setup, and required fields (project, location, googleAuthOptions) with experimental: true; updated troubleshooting to say “Vertex” and point to service account credentials.

^{Written for commit c7ed246. Summary will update on new commits. Review in cubic}

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[greptile-apps]

Greptile Summary

Added comprehensive Google Vertex AI configuration documentation to the First Class Models section. The new tab includes a working TypeScript example showing how to configure Vertex with service account credentials, explains the required experimental: true flag, documents the model object structure (project, location, googleAuthOptions), and adds Vertex to the API key troubleshooting table.

Key additions:

• New Google Vertex tab with complete configuration example
• Warning about experimental: true requirement (correctly enforced in LLMProvider.ts:156-161)
• Documentation of GoogleVertexProviderSettings type structure matching /packages/core/lib/v3/types/public/model.ts:31-38
• Service account credentials format with client_email and private_key fields
• Reference link to Vertex AI models documentation
• Troubleshooting table entry noting service account credentials requirement

Minor style issue:

• Model name inconsistency between code example (gemini-2.0-flash) and documentation text (gemini-2.5-flash)

Confidence Score: 4/5

• This documentation PR is safe to merge with a minor style inconsistency that should be addressed
• The documentation is accurate and matches the actual code implementation, including the experimental flag requirement and type definitions. Only flagged issue is a minor model name inconsistency between the code example and the explanatory text.
• No files require special attention - the single style comment addresses a minor consistency improvement

Important Files Changed

Filename	Overview
packages/docs/v3/configuration/models.mdx	Added Google Vertex AI tab with configuration example; includes experimental flag requirement, model object format, service account setup, and troubleshooting entry. Minor inconsistency in model name examples.

_{Last reviewed commit: 10eb0da}

[greptile-apps]

_{1 file reviewed, 1 comment}

_{Edit Code Review Agent Settings | Greptile}

[Kylejeong2]

looks good

[Kylejeong2]

we should somehow set reminder to update this when it's no longer experimental

[shrey150]

Merge activity

• Feb 20, 6:37 PM UTC: A user started a stack merge that includes this pull request via Graphite.
• Feb 20, 6:37 PM UTC: @shrey150 merged this pull request with Graphite.