Claude Code ANTHROPIC_BASE_URL is not respected

Requests still go to the default Anthropic endpoint despite setting ANTHROPIC_BASE_URL.

Symptoms

Traffic still reaches api.anthropic.com
Custom gateway receives no requests

Error signatures

ANTHROPIC_BASE_URL ignored

wrong endpoint

Possible causes

Variable set in a different shell than the one running Claude Code
Base URL missing the required path suffix
Auth token mismatch for the custom gateway

Solutions

Export the variable in the correct shell and validate the URL

risk: lowagentpending_review

Ensure the variable is exported in the active shell and the URL format matches the gateway.

Export ANTHROPIC_BASE_URL in the same shell session that launches Claude Code.
Confirm the URL format expected by your gateway (with or without a trailing path).
Set a matching ANTHROPIC_AUTH_TOKEN if your gateway requires it.

Commands

export ANTHROPIC_BASE_URL=https://your-gateway.example.com

env | grep ANTHROPIC

Verification

Inspect gateway logs to confirm requests arrive from Claude Code.

✓ 0 verified✕ 0 failed

Agent JSON

Canonical machine-readable representation of this issue:

{
  "issue_id": "48431fe8-4968-4dcb-b2aa-10d421c0e4b6",
  "slug": "claude-code-anthropic-base-url-not-working",
  "verification_status": "unverified",
  "canonical_json": "https://codekb.dev/v1/issues/claude-code-anthropic-base-url-not-working"
}