feat: allow custom Anthropic base URLs

[tsubasakong]

Summary

• add a configurable baseURL field to the Anthropic provider UI/server config
• normalize custom Anthropic-compatible endpoints so users can enter either the root URL or /v1
• keep the official Anthropic endpoint as the backward-compatible default for existing configs

Fixes #918.

---

Summary by cubic

Adds a configurable baseURL for the Anthropic provider to support custom Anthropic-compatible endpoints. Normalizes URLs and keeps https://api.anthropic.com/v1 as the default. Fixes #918.

• New Features

  • Adds baseURL field in the provider UI/config with default https://api.anthropic.com/v1 (ANTHROPIC_BASE_URL).
  • Normalizes user input: trims trailing slashes and ensures /v1 is present.
  • All Anthropic requests (model listing and LLM calls) now use the configured baseURL.

• Migration

  • No action needed for existing setups; default endpoint remains unchanged.
  • To use a custom proxy, set ANTHROPIC_BASE_URL or update the provider settings (accepts root URL or /v1).

^{Written for commit a640335. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 1 file

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="src/lib/models/providers/anthropic/index.ts">

<violation number="1" location="src/lib/models/providers/anthropic/index.ts:119">
P2: `baseURL` is not validated; invalid config values can normalize to malformed URLs and cause runtime fetch failures.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

P2: baseURL is not validated; invalid config values can normalize to malformed URLs and cause runtime fetch failures.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At src/lib/models/providers/anthropic/index.ts, line 119:

<comment>`baseURL` is not validated; invalid config values can normalize to malformed URLs and cause runtime fetch failures.</comment>

<file context>
@@ -97,6 +116,7 @@ class AnthropicProvider extends BaseModelProvider<AnthropicConfig> {
 
     return {
       apiKey: String(raw.apiKey),
+      baseURL: String(raw.baseURL ?? 'https://api.anthropic.com/v1'),
     };
   }
</file context>