adds model to metadata to estimated cost is calculated; corrects how to pass metadata in braintrust in the docs (#12022)

docs/my-website/docs/observability/braintrust.md

@@ -2,25 +2,24 @@ import Image from '@theme/IdealImage';
 import Tabs from '@theme/Tabs';
 import TabItem from '@theme/TabItem';
 
-# Braintrust - Evals + Logging 
+# Braintrust - Evals + Logging
 
 [Braintrust](https://www.braintrust.dev/) manages evaluations, logging, prompt playground, to data management for AI products.
 
-
 ## Quick Start
 
 ```python
-# pip install langfuse 
+# pip install braintrust
 import litellm
 import os
 
-# set env 
-os.environ["BRAINTRUST_API_KEY"] = "" 
+# set env
+os.environ["BRAINTRUST_API_KEY"] = ""
 os.environ['OPENAI_API_KEY']=""
 
 # set braintrust as a callback, litellm will send the data to braintrust
-litellm.callbacks = ["braintrust"] 
- 
+litellm.callbacks = ["braintrust"]
+
 # openai call
 response = litellm.completion(
   model="gpt-3.5-turbo",
@@ -30,16 +29,16 @@ response = litellm.completion(
 )
 ```
 
-
-
 ## OpenAI Proxy Usage
 
-1. Add keys to env 
+1. Add keys to env
+
 ```env
-BRAINTRUST_API_KEY="" 
+BRAINTRUST_API_KEY=""
 ```
 
-2. Add braintrust to callbacks 
+2. Add braintrust to callbacks
+
 ```yaml
 model_list:
   - model_name: gpt-3.5-turbo
@@ -47,12 +46,11 @@ model_list:
       model: gpt-3.5-turbo
       api_key: os.environ/OPENAI_API_KEY
 
-
 litellm_settings:
   callbacks: ["braintrust"]
 ```
 
-3. Test it! 
+3. Test it!
 
 ```bash
 curl -X POST 'http://0.0.0.0:4000/chat/completions' \
@@ -69,6 +67,8 @@ curl -X POST 'http://0.0.0.0:4000/chat/completions' \
 
 ## Advanced - pass Project ID or name
 
+It is recommended that you include the `project_id` or `project_name` to ensure your traces are being written out to the correct Braintrust project.
+
 <Tabs>
 <TabItem value="sdk" label="SDK">
 
@@ -77,12 +77,28 @@ response = litellm.completion(
   model="gpt-3.5-turbo",
   messages=[
     {"role": "user", "content": "Hi 👋 - i'm openai"}
-  ], 
+  ],
   metadata={
     "project_id": "1234",
     # passing project_name will try to find a project with that name, or create one if it doesn't exist
     # if both project_id and project_name are passed, project_id will be used
-    # "project_name": "my-special-project" 
+    # "project_name": "my-special-project"
+  }
+)
+```
+
+Note: Other `metadata` can be included here as well when using the SDK.
+
+```python
+response = litellm.completion(
+  model="gpt-3.5-turbo",
+  messages=[
+    {"role": "user", "content": "Hi 👋 - i'm openai"}
+  ],
+  metadata={
+    "project_id": "1234",
+    "item1": "an item",
+    "item2": "another item"
   }
 )
 ```
@@ -127,7 +143,7 @@ response = client.chat.completions.create(
         }
     ],
     extra_body={ # pass in any provider-specific param, if not supported by openai, https://docs.litellm.ai/docs/completion/input#provider-specific-params
-        "metadata": { # 👈 use for logging additional params (e.g. to langfuse)
+        "metadata": { # 👈 use for logging additional params (e.g. to braintrust)
             "project_id": "my-special-project"
         }
     }
@@ -141,10 +157,10 @@ For more examples, [**Click Here**](../proxy/user_keys.md#chatcompletions)
 </TabItem>
 </Tabs>
 
-## Full API Spec 
+## Full API Spec
 
-Here's everything you can pass in metadata for a braintrust request 
+Here's everything you can pass in metadata for a braintrust request
 
-`braintrust_*` - any metadata field starting with `braintrust_` will be passed as metadata to the logging request 
+`braintrust_*` - If you are adding metadata from _proxy request headers_, any metadata field starting with `braintrust_` will be passed as metadata to the logging request. If you are using the SDK, just pass your metadata like normal (e.g., `metadata={"project_name": "my-test-project", "item1": "an item", "item2": "another item"}`)
 
-`project_id`  - set the project id for a braintrust call. Default is `litellm`. 
+`project_id` - Set the project id for a braintrust call. Default is `litellm`.

litellm/integrations/braintrust_logging.py

@@ -111,7 +111,7 @@ class BraintrustLogger(CustomLogger):
     @staticmethod
     def add_metadata_from_header(litellm_params: dict, metadata: dict) -> dict:
         """
-        Adds metadata from proxy request headers to Langfuse logging if keys start with "langfuse_"
+        Adds metadata from proxy request headers to Braintrust logging if keys start with "braintrust_"
         and overwrites litellm_params.metadata if already included.
 
         For example if you want to append your trace to an existing `trace_id` via header, send
@@ -254,6 +254,11 @@ class BraintrustLogger(CustomLogger):
             if cost is not None:
                 clean_metadata["litellm_response_cost"] = cost
 
+            # metadata.model is required for braintrust to calculate the "Estimated cost" metric
+            litellm_model = kwargs.get("model", None)
+            if litellm_model is not None:
+                clean_metadata["model"] = litellm_model
+
             metrics: Optional[dict] = None
             usage_obj = getattr(response_obj, "usage", None)
             if usage_obj and isinstance(usage_obj, litellm.Usage):
@@ -391,6 +396,11 @@ class BraintrustLogger(CustomLogger):
             if cost is not None:
                 clean_metadata["litellm_response_cost"] = cost
 
+            # metadata.model is required for braintrust to calculate the "Estimated cost" metric
+            litellm_model = kwargs.get("model", None)
+            if litellm_model is not None:
+                clean_metadata["model"] = litellm_model
+
             metrics: Optional[dict] = None
             usage_obj = getattr(response_obj, "usage", None)
             if usage_obj and isinstance(usage_obj, litellm.Usage):