diff --git a/packages/opencode/src/tool/mcp-exa.ts b/packages/opencode/src/tool/mcp-exa.ts
index 638d68c245..3340d84efd 100644
--- a/packages/opencode/src/tool/mcp-exa.ts
+++ b/packages/opencode/src/tool/mcp-exa.ts
@@ -1,7 +1,9 @@
 import { Duration, Effect, Schema } from "effect"
 import { HttpClient, HttpClientRequest } from "effect/unstable/http"
 
-const URL = "https://mcp.exa.ai/mcp"
+const URL = process.env.EXA_API_KEY
+  ? `https://mcp.exa.ai/mcp?exaApiKey=${encodeURIComponent(process.env.EXA_API_KEY)}`
+  : "https://mcp.exa.ai/mcp"
 
 const McpResult = Schema.Struct({
   result: Schema.Struct({