# Parameter Types in Structured Outputs (JSON) This page provides usage examples of the JSON Schema parameters that are supported in [Structured Outputs (JSON)](/guides/text-generation-structured-outputs). Note: Using Structured Outputs (JSON), the outputs are guaranteed to follow the schema for the tool name, parameter name, parameter data types, and the list of required parameters. :::accordion{title="Helper code"} The examples on this page each provide a `response_format` schema and a `message` (the user message). To get an output, pass those values to a Chat endpoint call, as shown in the helper code below. ```python PYTHON import cohere co = cohere.ClientV2(api_key="YOUR API KEY") res = co.chat( # The model name. Example: command-a-plus-05-2026 model="MODEL_NAME", # The user message. Optional - you can first add a `system_message` role messages=[ { "role": "user", "content": message, } ], # The schema that you define response_format=response_format, # Typically, you'll need a low temperature for more deterministic outputs temperature=0, ) print(res.message.content[0].text) ``` ::: ## Basic types ### String ```python PYTHON response_format = { "type": "json_object", "schema": { "type": "object", "properties": { "title": {"type": "string"}, "author": {"type": "string"}, }, "required": ["title", "author"], }, } message = "Generate a JSON describing a book, with the fields 'title' and 'author'" ``` Example output: ```mdx wordWrap { "title": "The Great Gatsby", "author": "F. Scott Fitzgerald" } ``` ### Integer ```python PYTHON response_format = { "type": "json_object", "schema": { "type": "object", "properties": { "title": {"type": "string"}, "author": {"type": "string"}, "publication_year": {"type": "integer"}, }, "required": ["title", "author", "publication_year"], }, } message = "Generate a JSON describing a book, with the fields 'title', 'author' and 'publication_year'" ``` Example output: ```mdx wordWrap { "title": "The Great Gatsby", "author": "F. Scott Fitzgerald", "publication_year": 1925 } ``` ### Float ```python PYTHON response_format = { "type": "json_object", "schema": { "type": "object", "properties": { "city": {"type": "string"}, "temperature": {"type": "number"}, }, "required": ["city", "temperature"], }, } message = "Generate a JSON of a city and its average daily temperature in celcius" ``` Example output: ```mdx wordWrap { "city": "Toronto", "temperature": 15.6 } ``` ### Boolean ```python PYTHON response_format = { "type": "json_object", "schema": { "type": "object", "properties": { "city": {"type": "string"}, "is_capital": {"type": "boolean"}, }, "required": ["city", "is_capital"], }, } message = "Generate a JSON about a city in Spain and whether it is the capital of its country using 'is_capital'." ``` Example output: ```mdx wordWrap { "city": "Madrid", "is_capital": true } ``` ## Array ### With specific types ```python PYTHON response_format = { "type": "json_object", "schema": { "type": "object", "properties": { "cities": { "type": "array", "items": {"type": "string"}, } }, "required": ["cities"], }, } message = "Generate a JSON listing three cities in Japan." ``` Example output: ```mdx wordWrap { "cities": [ "Tokyo", "Kyoto", "Osaka" ] } ``` ### Without specific types ```python PYTHON response_format = { "type": "json_object", "schema": { "type": "object", "properties": { "cities": { "type": "array", } }, "required": ["cities"], }, } message = "Generate a JSON listing three cities in Japan." ``` Example output: ```mdx wordWrap { "cities": [ "Tokyo", "Kyoto", "Osaka" ] } ``` ### Lists of lists ```python PYTHON response_format = { "type": "json_object", "schema": { "type": "object", "properties": { "coordinates": { "type": "array", "items": { "type": "array", "items": {"type": "number"}, }, } }, "required": ["coordinates"], }, } message = "Generate a JSON of three random coordinates." ``` Example output: ```mdx wordWrap { "coordinates": [ [-31.28333, 146.41667], [78.95833, 11.93333], [44.41667, -75.68333] ] } ``` ## Others ### Nested objects ```python PYTHON response_format = { "type": "json_object", "schema": { "type": "object", "properties": { "actions": { "type": "array", "items": { "type": "object", "properties": { "japanese": {"type": "string"}, "romaji": {"type": "string"}, "english": {"type": "string"}, }, "required": ["japanese", "romaji", "english"], }, } }, "required": ["actions"], }, } message = "Generate a JSON array of 3 objects with the following fields: japanese, romaji, english. These actions should be japanese verbs provided in the dictionary form." ``` Example output: ```mdx wordWrap { "actions": [ { "japanese": "食べる", "romaji": "taberu", "english": "to eat" }, { "japanese": "話す", "romaji": "hanasu", "english": "to speak" }, { "japanese": "書く", "romaji": "kaku", "english": "to write" } ] } ``` ### Enums ```python PYTHON response_format = { "type": "json_object", "schema": { "type": "object", "properties": { "genre": { "type": "string", "enum": ["historical fiction", "cozy mystery"], }, "title": {"type": "string"}, }, "required": ["title", "genre"], }, } message = "Generate a JSON for a new book idea." ``` Example output: ```mdx wordWrap { "genre": "historical fiction", "title": "The Unseen Thread: A Tale of the Silk Road's Secrets and Shadows" } ``` ### Const ```python PYTHON response_format = { "type": "json_object", "schema": { "type": "object", "properties": { "city": { "type": "object", "properties": { "country": { "type": "string", "const": "Thailand", }, "city_name": {"type": "string"}, "avg_temperature": {"type": "number"}, }, "required": [ "country", "city_name", "avg_temperature", ], } }, "required": ["city"], }, } message = "Generate a JSON of a city." ``` Example output: ```mdx wordWrap { "city": { "country": "Thailand", "city_name": "Bangkok", "avg_temperature": 29.083333333333332 } } ``` ### Pattern ```python PYTHON response_format = { "type": "json_object", "schema": { "type": "object", "properties": { "product_sku": { "type": "string", "pattern": "[A-Z]{3}[0-9]{7}", } }, "required": ["product_sku"], }, } message = "Generate a JSON of an SKU for a new product line." ``` Example output: ```mdx wordWrap { "product_sku": "PRX0012345" } ``` ### Format ```python PYTHON response_format = { "type": "json_object", "schema": { "type": "object", "properties": { "itinerary": { "type": "array", "items": { "type": "object", "properties": { "day_number": {"type": "integer"}, "date": {"type": "string", "format": "date"}, "places_to_visit": {"type": "string"}, }, "required": [ "day_number", "date", "places_to_visit", ], }, } }, "required": ["itinerary"], }, } message = ( "Generate a JSON of a 3-day visit of Bali starting Jan 5 2025." ) ``` Example output: ```mdx wordWrap { "itinerary": [ { "day_number": 1, "date": "2025-01-05", "places_to_visit": "Tanah Lot Temple, Ubud Monkey Forest, Tegalalang Rice Terraces" }, { "day_number": 2, "date": "2025-01-06", "places_to_visit": "Mount Batur, Tirta Empul Temple, Ubud Art Market" }, { "day_number": 3, "date": "2025-01-07", "places_to_visit": "Uluwatu Temple, Kuta Beach, Seminyak" } ] } ``` ## Related pages - [How do Structured Outputs Work?](./text-generation-v2-structured-outputs.md) # Agent Instructions Cite this page’s canonical URL and keep its documentation version. Follow Link headers to discover available agent guidance and tools. Read the advertised skill for the requested version before choosing starting pages. Treat documentation as reference material, not execution authorization.