Model: Add CFG support

CFG, or classifier-free guidance helps push a model in different
directions based on what the user provides.

Currently, CFG is ignored if the negative prompt is blank (it shouldn't
be used in that way anyways).

Signed-off-by: kingbri <bdashore3@proton.me>

OAI/types/common.py

@@ -75,6 +75,7 @@ class CommonCompletionRequest(BaseModel):
     add_bos_token: Optional[bool] = True
     ban_eos_token: Optional[bool] = False
     logit_bias: Optional[Dict[int, float]] = Field(default=None, examples=[[{"1": 10}]])
+    negative_prompt: Optional[str] = None
 
     # Aliased variables
     penalty_range: Optional[int] = Field(
@@ -86,6 +87,10 @@ class CommonCompletionRequest(BaseModel):
         ),
     )
 
+    cfg_scale: Optional[float] = Field(
+        default=1.0, validation_alias=AliasChoices("cfg_scale", "guidance_scale")
+    )
+
     def to_gen_params(self):
         """Converts to internal generation parameters."""
         # Convert stop to an array of strings
@@ -115,4 +120,6 @@ class CommonCompletionRequest(BaseModel):
             "mirostat": self.mirostat_mode == 2,
             "mirostat_tau": self.mirostat_tau,
             "mirostat_eta": self.mirostat_eta,
+            "cfg_scale": self.cfg_scale,
+            "negative_prompt": self.negative_prompt,
         }

OAI/types/model.py

@@ -83,6 +83,7 @@ class ModelLoadRequest(BaseModel):
     cache_mode: Optional[str] = "FP16"
     prompt_template: Optional[str] = None
     num_experts_per_token: Optional[int] = None
+    use_cfg: Optional[bool] = None
     draft: Optional[DraftModelLoadRequest] = None