docs: add GPTZZZ provider

packages/web/src/content/docs/providers.mdx

@@ -1258,6 +1258,47 @@ The `global` region improves availability and reduces errors at no extra cost. U
 
 ---
 
+### GPTZZZ
+
+[GPTZZZ](https://gptzzz.ai) is an OpenAI-compatible gateway. Set the base URL and list the model IDs your account can reach.
+
+```json title="opencode.json" "gptzzz" {5, 6, 8, 10-17}
+{
+  "$schema": "https://opencode.ai/config.json",
+  "provider": {
+    "gptzzz": {
+      "npm": "@ai-sdk/openai-compatible",
+      "name": "GPTZZZ",
+      "options": {
+        "baseURL": "https://gptzzz.ai/v1"
+      },
+      "models": {
+        "gpt-6-astra": {
+          "name": "GPT-6 Astra"
+        },
+        "gpt-5.6": {
+          "name": "GPT-5.6"
+        }
+      }
+    }
+  }
+}
+```
+
+Set the API key with the `/connect` command, or export `GPTZZZ_API_KEY`.
+
+The catalog differs between account groups, so take the exact model IDs from `GET /v1/models` rather than from this example:
+
+```bash
+curl -H "Authorization: Bearer $GPTZZZ_API_KEY" https://gptzzz.ai/v1/models
+```
+
+:::tip
+`reasoning_effort` is supported, but the accepted values differ per model. `gpt-6-astra` takes `low` through `max` and rejects `none`; the GPT-5.6 models also accept `none`.
+:::
+
+---
+
 ### Groq
 
 1. Head over to the [Groq console](https://console.groq.com/), click **Create API Key**, and copy the key.