---
type: concept
x-llmwiki:
  schemaVersion: "0.1"
  contentHash: f8054281fa55709dafdf00e0742b8b738627314069021e70ba7b39fb61d60987
  pageDirectory: concepts
  sources:
    - foundation-model-rest-api-reference-databricks-on-aws.md
  confidence: 1
  provenanceState: extracted
  freshnessStatus: unverified
  aliases:
    - content-block-types-databricks-apis
    - CBT(A
  citations:
    - file: foundation-model-rest-api-reference-databricks-on-aws.md
title: Content Block Types (Databricks APIs)
description: "The supported content types in messages across Databricks APIs: TextContent, ImageContent, ReasoningContent, DocumentContent, and FileContent."
tags:
  - data-types
  - api
  - content-blocks
timestamp: "2026-06-19T18:55:13.537Z"
---

Here is the wiki page for "Content Block Types (Databricks APIs)".

## Content Block Types (Databricks APIs)

**Content Block Types** define the structure of content within input and output messages for Foundation Model REST API Reference (Databricks APIs)|Databricks Foundation Model APIs. The type of content block is determined by a `type` field in the JSON request or response. These blocks are used in both the [Chat Completions API](/concepts/chat-completions-api.md) and the [Responses API](/concepts/responses-api.md) to represent different modalities of data. ^[foundation-model-rest-api-reference-databricks-on-aws.md]

### Content Blocks in the Responses API

The Responses API uses `content_block` objects to define the kind of content in input and output messages. The following content block types are available:

- **InputText**: Represents plain text input.
- **OutputText**: Represents plain text output from the model.
- **InputImage**: Represents an image input.
- **InputFile**: Represents a file input.
- **FunctionCall**: Represents a function call made by the model.
- **FunctionCallOutput**: Provides the result of a function call back to the model.
- **CustomToolCall**: Returned in the response `output` array when a custom tool is called. Unlike function calls, custom tool calls return plain text `input` instead of JSON `arguments`.
- **CustomToolCallOutput**: Used as input to provide the result of a custom tool call back to the model in a multi-turn conversation.

^[foundation-model-rest-api-reference-databricks-on-aws.md]

### Content Items in the Chat Completions API

The Chat Completions API uses `ContentItem` to define the content of a message. `ContentItem` is one of the following content types:

- **TextContent**: Represents text content within a message.
- **ImageContent**: Represents an image within a message, typically via an image URL.
- **ReasoningContent**: Represents reasoning step content generated by reasoning models. It may contain sub-types:
    - **TextSummary**: A textual summary of the reasoning step.
    - **EncryptedTextSummary**: An encrypted version of the reasoning summary.
- **DocumentContent**: Represents a document input, such as a PDF or Word file. This type is only for requests and includes a **Source** field.
- **FileContent**: Represents a general file input.

^[foundation-model-rest-api-reference-databricks-on-aws.md]

### Context and Usage

Content blocks and content items enable multi-modal interactions with models, allowing inputs that include text, images, and documents. The structure is designed to be compatible with [OpenAI API Compatibility (Databricks)|OpenAI's REST API format](/concepts/openai-compatible-api-interface.md) for ease of migration. ^[foundation-model-rest-api-reference-databricks-on-aws.md]

For the Responses API, custom tools (`CustomToolCall`, `CustomToolCallOutput`) and grammar-based output formats are only available with GPT-5 series models (`gpt-5`, `gpt-5.1`, `gpt-5.2`). ^[foundation-model-rest-api-reference-databricks-on-aws.md]

### Related Concepts

- [Foundation Model REST API Reference (Databricks APIs)](/concepts/foundation-models-apis-on-databricks.md)
- [Chat Completions API](/concepts/chat-completions-api.md)
- [Responses API](/concepts/responses-api.md)
- [OpenAI API Compatibility (Databricks)](/concepts/openai-compatible-api-interface.md)
- [Function Calling (Databricks)](/concepts/ai-functions-databricks.md)
- [Structured Outputs (Databricks)](/concepts/structured-outputs-in-foundation-model-apis.md)

### Sources

- foundation-model-rest-api-reference-databricks-on-aws.md

# Citations

1. [foundation-model-rest-api-reference-databricks-on-aws.md](/references/foundation-model-rest-api-reference-databricks-on-aws-26351d38.md)
