Source Intelligence
Sweep 28 Aug 2026 · 00:00Z Build v2.1.250 478 read Stable v2.1.236 Latest v2.1.250 Next v2.1.250 Feeds RSS JSON llms.txt

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

Reference / Environment variables

ANTHROPIC_BEDROCK_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 the Amazon Bedrock endpoint URL. Use for custom Amazon Bedrock endpoints or when routing through an [LLM gateway](/docs/en/llm-gateway). See [Amazon Bedrock](/docs/en/amazon-bedrock)

Anthropic's own wording. Read off Environment variables, captured 2026-08-28.

Presence across releases

ReleasesReadingDeclared typeDefault
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

  1. 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

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_bedrock, up to twelve of them.

ANTHROPIC_BEDROCK_MANTLE_BASE_URLOverride the Amazon Bedrock Mantle endpoint URL. See [Mantle endpoint](/docs/en/amazon-bedrock#use-the-mantle-endpoint) 2.1.138 ANTHROPIC_BEDROCK_REGION_PREFIXCross-region inference profile prefix (us, eu, apac, jp, au, or global) Claude Code tries first instead of the one derived from the AWS region. Ignored in AWS GovCloud regions. Requires Claude Code v2.1.224 or later. See [Amazon Bedrock](/docs/en/amazon-bedrock#cross-region-inference-profile-prefixes) 2.1.224 ANTHROPIC_BEDROCK_SERVICE_TIERAmazon Bedrock [service tier](https://docs.aws.amazon.com/bedrock/latest/userguide/service-tiers-inference.html) (default, flex, or priority). Sent as the X-Amzn-Bedrock-Service-Tier header. See [Amazon Bedrock](/docs/en/amazon-bedrock#service-tiers) 2.1.138

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.