Revert "remove Vercel AI Gateway and Vercel Sandbox (#33067)"

This reverts commit febc4cfec0.

plugins/model-providers/ai-gateway/__init__.py

@@ -0,0 +1,43 @@
+"""Vercel AI Gateway provider profile.
+
+AI Gateway routes to multiple backends. Hermes sends attribution
+headers and full reasoning config passthrough.
+"""
+
+from typing import Any
+
+from providers import register_provider
+from providers.base import ProviderProfile
+
+
+class VercelAIGatewayProfile(ProviderProfile):
+    """Vercel AI Gateway — attribution headers + reasoning passthrough."""
+
+    def build_api_kwargs_extras(
+        self,
+        *,
+        reasoning_config: dict | None = None,
+        supports_reasoning: bool = True,
+        **ctx: Any,
+    ) -> tuple[dict[str, Any], dict[str, Any]]:
+        extra_body: dict[str, Any] = {}
+        if supports_reasoning and reasoning_config is not None:
+            extra_body["reasoning"] = dict(reasoning_config)
+        elif supports_reasoning:
+            extra_body["reasoning"] = {"enabled": True, "effort": "medium"}
+        return extra_body, {}
+
+
+vercel = VercelAIGatewayProfile(
+    name="ai-gateway",
+    aliases=("vercel", "vercel-ai-gateway", "ai_gateway", "aigateway"),
+    env_vars=("AI_GATEWAY_API_KEY",),
+    base_url="https://ai-gateway.vercel.sh/v1",
+    default_headers={
+        "HTTP-Referer": "https://hermes-agent.nousresearch.com",
+        "X-Title": "Hermes Agent",
+    },
+    default_aux_model="google/gemini-3-flash",
+)
+
+register_provider(vercel)

plugins/model-providers/ai-gateway/plugin.yaml

@@ -0,0 +1,5 @@
+name: ai-gateway-provider
+kind: model-provider
+version: 1.0.0
+description: Vercel AI Gateway
+author: Nous Research