diff --git a/app/services/external_model_service.py b/app/services/external_model_service.py
new file mode 100644
index 0000000..7a574fa
--- /dev/null
+++ b/app/services/external_model_service.py
@@ -0,0 +1,46 @@
+import requests
+import os
+
+class ExternalModelService:
+    def generate(self, provider: str, model: str, prompt: str):
+        if provider == "openai":
+            return self.openai(model, prompt)
+
+        if provider == "anthropic":
+            return self.anthropic(model, prompt)
+
+        if provider == "mistral":
+            return self.mistral(model, prompt)
+
+        return "Erro: provider desconhecido."
+
+    def openai(self, model, prompt):
+        url = "https://api.openai.com/v1/chat/completions"
+        headers = {"Authorization": f"Bearer {os.getenv('OPENAI_API_KEY')}"}
+        payload = {
+            "model": model,
+            "messages": [{"role": "user", "content": prompt}]
+        }
+        r = requests.post(url, json=payload, headers=headers)
+        return r.json()["choices"][0]["message"]["content"]
+
+    def anthropic(self, model, prompt):
+        url = "https://api.anthropic.com/v1/messages"
+        headers = {"x-api-key": os.getenv("ANTHROPIC_API_KEY")}
+        payload = {
+            "model": model,
+            "max_tokens": 4096,
+            "messages": [{"role": "user", "content": prompt}]
+        }
+        r = requests.post(url, json=payload, headers=headers)
+        return r.json()["content"][0]["text"]
+
+    def mistral(self, model, prompt):
+        url = "https://api.mistral.ai/v1/chat/completions"
+        headers = {"Authorization": f"Bearer {os.getenv('MISTRAL_API_KEY')}"}
+        payload = {
+            "model": model,
+            "messages": [{"role": "user", "content": prompt}]
+        }
+        r = requests.post(url, json=payload, headers=headers)
+        return r.json()["choices"][0]["message"]["content"]