docs(json_mode.md): add json mode to docs

docs/my-website/docs/completion/json_mode.md

@@ -0,0 +1,137 @@
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+# JSON Mode
+
+## Quick Start 
+
+<Tabs>
+<TabItem value="sdk" label="SDK">
+
+```python
+from litellm import completion
+import os 
+
+os.environ["OPENAI_API_KEY"] = ""
+
+response = completion(
+  model="gpt-4o-mini",
+  response_format={ "type": "json_object" },
+  messages=[
+    {"role": "system", "content": "You are a helpful assistant designed to output JSON."},
+    {"role": "user", "content": "Who won the world series in 2020?"}
+  ]
+)
+print(response.choices[0].message.content)
+```
+</TabItem>
+<TabItem value="proxy" label="PROXY">
+
+```bash
+curl http://0.0.0.0:4000/v1/chat/completions \
+  -H "Content-Type: application/json" \
+  -H "Authorization: Bearer $LITELLM_KEY" \
+  -d '{
+    "model": "gpt-4o-mini",
+    "response_format": { "type": "json_object" },
+    "messages": [
+      {
+        "role": "system",
+        "content": "You are a helpful assistant designed to output JSON."
+      },
+      {
+        "role": "user",
+        "content": "Who won the world series in 2020?"
+      }
+    ]
+  }'
+```
+</TabItem>
+</Tabs>
+
+## Check Model Support 
+
+Call `litellm.get_supported_openai_params` to check if a model/provider supports `response_format`. 
+
+```python
+from litellm import get_supported_openai_params
+
+params = get_supported_openai_params(model="anthropic.claude-3", custom_llm_provider="bedrock")
+
+assert "response_format" in params
+```
+
+## Validate JSON Schema 
+
+For VertexAI models, LiteLLM supports passing the `response_schema` and validating the JSON output.
+
+This works across Gemini (`vertex_ai_beta/`) + Anthropic (`vertex_ai/`) models. 
+
+
+<Tabs>
+<TabItem value="sdk" label="SDK">
+
+```python
+# !gcloud auth application-default login - run this to add vertex credentials to your env
+
+from litellm import completion 
+
+messages = [{"role": "user", "content": "List 5 cookie recipes"}]
+
+response_schema = {
+    "type": "array",
+    "items": {
+        "type": "object",
+        "properties": {
+            "recipe_name": {
+                "type": "string",
+            },
+        },
+        "required": ["recipe_name"],
+    },
+}
+
+resp = completion(
+    model="vertex_ai_beta/gemini-1.5-pro",
+    messages=messages,
+    response_format={
+        "type": "json_object",
+        "response_schema": response_schema,
+        "enforce_validation": True, # client-side json schema validation
+    },
+    vertex_location="us-east5",
+)
+
+print("Received={}".format(resp))
+```
+</TabItem>
+<TabItem value="proxy" label="PROXY">
+
+```bash
+curl http://0.0.0.0:4000/v1/chat/completions \
+  -H "Content-Type: application/json" \
+  -H "Authorization: Bearer $LITELLM_API_KEY" \
+  -d '{
+    "model": "vertex_ai_beta/gemini-1.5-pro",
+    "messages": [{"role": "user", "content": "List 5 cookie recipes"}]
+    "response_format": { 
+        "type": "json_object",
+        "enforce_validation: true, 
+        "response_schema": { 
+            "type": "array",
+            "items": {
+                "type": "object",
+                "properties": {
+                    "recipe_name": {
+                        "type": "string",
+                    },
+                },
+                "required": ["recipe_name"],
+            },
+        }
+    },
+  }'
+```
+
+</TabItem>
+</Tabs>

docs/my-website/sidebars.js

@@ -92,6 +92,7 @@ const sidebars = {
       items: [
         "completion/input",
         "completion/provider_specific_params",
+        "completion/json_mode",
         "completion/drop_params",
         "completion/prompt_formatting",
         "completion/output",