fix(api): add undici fetch wrapper for localhost connections

Fixes connection issues with localhost API providers on Node.js 20+

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Pablo Vitasso

src/api/providers/base-openai-compatible-provider.ts

@@ -3,6 +3,11 @@ import OpenAI from "openai"
 
 import type { ModelInfo } from "@klaus-code/types"
 
+// Install undici-based fetch wrapper when using OpenAI-compatible providers
+// This fixes connection issues with localhost on Node.js 20+
+import { installUndisciFetchWrapper } from "../utils/undici-fetch-wrapper"
+installUndisciFetchWrapper()
+
 import { type ApiHandlerOptions, getModelMaxOutputTokens } from "../../shared/api"
 import { TagMatcher } from "../../utils/tag-matcher"
 import { ApiStream, ApiStreamUsageChunk } from "../transform/stream"

src/api/providers/router-provider.ts

@@ -2,6 +2,11 @@ import OpenAI from "openai"
 
 import { type ModelInfo, type ModelRecord } from "@klaus-code/types"
 
+// Install undici-based fetch wrapper when using router-based providers
+// This fixes connection issues with localhost on Node.js 20+
+import { installUndisciFetchWrapper } from "../utils/undici-fetch-wrapper"
+installUndisciFetchWrapper()
+
 import { ApiHandlerOptions, RouterName } from "../../shared/api"
 
 import { BaseProvider } from "./base-provider"