feat: add openai-compatible model gateway

backend/apps/modelhub/models.py

@@ -0,0 +1,88 @@
+import uuid
+
+from django.conf import settings
+from django.db import models
+
+
+class ModelProvider(models.Model):
+    name = models.CharField(max_length=120, unique=True)
+    base_url = models.URLField(max_length=500)
+    api_key_encrypted = models.TextField(blank=True)
+    enabled = models.BooleanField(default=True)
+    default_timeout_seconds = models.PositiveIntegerField(default=60)
+    created_by = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        null=True,
+        blank=True,
+        on_delete=models.SET_NULL,
+        related_name="created_model_providers",
+    )
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        ordering = ["name"]
+
+
+class ModelDeployment(models.Model):
+    provider = models.ForeignKey(
+        ModelProvider,
+        on_delete=models.PROTECT,
+        related_name="deployments",
+    )
+    display_name = models.CharField(max_length=120)
+    model_name = models.CharField(max_length=160)
+    capability = models.CharField(max_length=40, default="text_chat")
+    default_temperature = models.FloatField(default=0.2)
+    max_output_tokens = models.PositiveIntegerField(default=2048)
+    enabled = models.BooleanField(default=True)
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        ordering = ["provider__name", "display_name"]
+        constraints = [
+            models.UniqueConstraint(
+                fields=["provider", "model_name"],
+                name="unique_provider_model_name",
+            )
+        ]
+
+
+class ModelInvocation(models.Model):
+    public_id = models.UUIDField(default=uuid.uuid4, unique=True, editable=False)
+    deployment = models.ForeignKey(
+        ModelDeployment,
+        null=True,
+        blank=True,
+        on_delete=models.SET_NULL,
+        related_name="invocations",
+    )
+    invocation_type = models.CharField(max_length=40, default="model_test")
+    status = models.CharField(max_length=24, default="queued")
+    model_snapshot = models.JSONField(default=dict, blank=True)
+    input_snapshot = models.JSONField(default=dict, blank=True)
+    output_text = models.TextField(blank=True)
+    input_tokens = models.PositiveIntegerField(null=True, blank=True)
+    output_tokens = models.PositiveIntegerField(null=True, blank=True)
+    duration_ms = models.PositiveIntegerField(default=0)
+    retry_count = models.PositiveIntegerField(default=0)
+    error_code = models.CharField(max_length=80, blank=True)
+    error_message = models.TextField(blank=True)
+    created_by = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        null=True,
+        blank=True,
+        on_delete=models.SET_NULL,
+        related_name="model_invocations",
+    )
+    created_at = models.DateTimeField(auto_now_add=True)
+    started_at = models.DateTimeField(null=True, blank=True)
+    finished_at = models.DateTimeField(null=True, blank=True)
+
+    class Meta:
+        ordering = ["-created_at"]
+        indexes = [
+            models.Index(fields=["status", "created_at"]),
+            models.Index(fields=["invocation_type", "created_at"]),
+        ]