ANTHROPIC_VERTEX_BASE_URL
A Claude Code environment variable, read out of the shipped bundle. It has been in the build since v2.1.138, including the newest one read.
What it is
Override Google Cloud's Agent Platform endpoint URL. Use for custom Google Cloud's Agent Platform endpoints or when routing through an [LLM gateway](/docs/en/llm-gateway). See [Google Cloud's Agent Platform](/docs/en/google-vertex-ai)
Anthropic's own wording. Read off Environment variables, captured 2026-08-28.
Presence across releases
| Releases | Reading | Declared type | Default |
|---|---|---|---|
| 2.1.245 – 2.1.250 5 releases | never mined | — | — |
| 2.1.160 – 2.1.243 75 releases | in the build | str | — |
| 2.1.138 – 2.1.159 20 releases | in the build | — | — |
A row reading never mined is a release with no archived bundle behind it. Nothing was read out of it, so nothing here says whether the name was in it. A declared type or a default is only ever what that release's own bundle stated.
Changelog entries naming it
-
v2.1.237System prompt caching now requires a recognised endpoint
If you point Claude at a proxy or custom gateway, the system prompt is no longer cached.
named in this entry
Documentation pages
- Environment variables reference table Claude Code CLI
- Claude Code on Google Cloud's Agent Platform mentions it Claude Code CLI
- Connect Claude Code to an LLM gateway mentions it Claude Code CLI
- Gateway protocol reference mentions it Claude Code CLI
- Roll out an LLM gateway for your organization mentions it Claude Code CLI
- How Claude Code uses prompt caching mentions it Claude Code CLI
- Enterprise deployment overview mentions it Claude Code CLI
A reference table page is one whose own table defines this name, and it is where the description above came from. A page that mentions it carries the name somewhere in its text and may say nothing about it at all. Every page carrying it.
Names beside it
Every environment variable in the inventory starting anthropic_vertex, up to twelve of them.
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the environment variable does. All environment variables.