Generated Metadata

Mixedbread Stores automatically generate metadata for each file ingested. This generated metadata provides structured information about the content of the file, including language, size, headings, number of pages, and more.

The generated metadata can be retrieved using the generated_metadata chunk field.

Metadata Types

The generated_metadata object is a typed structure discriminated by the type field. If type is not present, it is inferred from file_type (MIME); otherwise it defaults to text.

Supported type values: markdown, text, pdf, code, audio, video, image.

Every metadata object includes a file_extension field (e.g., ".mp3", ".pdf") reflecting the original file extension.

For a full list of supported file formats, see Supported File Types.

Markdown - Heading Extraction

When processing markdown files, the system automatically extracts and preserves heading structure to enhance search relevance and provide context. This feature works for all markdown formats (.md, .markdown, .mdx).

What You Get

Each markdown chunk’s generated_metadata includes:

type: Always "markdown".
file_type: Always "text/markdown".
language: Detected language of the text.
word_count: Word count for the chunk.
file_size: File size in bytes.
chunk_headings: Headings found within the current chunk ([{ level: number, text: string }]).
heading_context: The document structure context leading up to this chunk ([{ level: number, text: string }]).
start_line: Starting line number of the chunk in the source file.
num_lines: Number of lines in the chunk.

Example Output

Consider this markdown document:

# Getting Started
## Installation
### Prerequisites
You need Python 3.8+ installed.
...

### Setup
Run the following command:

```bash
pip install package
```
...

## Configuration
### Environment Variables
Set these variables in your `.env` file.

### Database Setup
Configure your database connection.

When processed, the chunks would have generated_metadata like this:

Chunk 1 (Prerequisites section):

{
  "type": "markdown",
  "file_type": "text/markdown",
  "language": "en",
  "word_count": 6,
  "file_size": 1234,
  "chunk_headings": [
    {"level": 1, "text": "Getting Started"},
    {"level": 2, "text": "Installation"},
    {"level": 3, "text": "Prerequisites"}
  ],
  "heading_context": []
}

Chunk 2 (Setup section):

{
  "type": "markdown",
  "file_type": "text/markdown",
  "language": "en",
  "word_count": 12,
  "file_size": 1234,
  "chunk_headings": [
    {"level": 3, "text": "Setup"}
  ],
  "heading_context": [
    {"level": 1, "text": "Getting Started"},
    {"level": 2, "text": "Installation"},
    {"level": 3, "text": "Prerequisites"}
  ]
}

Chunk 3 (Configuration section):

{
  "type": "markdown",
  "file_type": "text/markdown",
  "language": "en",
  "word_count": 20,
  "file_size": 1234,
  "chunk_headings": [
    {"level": 2, "text": "Configuration"},
    {"level": 3, "text": "Environment Variables"},
    {"level": 3, "text": "Database Setup"}
  ],
  "heading_context": [
    {"level": 1, "text": "Getting Started"},
    {"level": 2, "text": "Installation"},
    {"level": 3, "text": "Setup"}
  ]
}

Text - Common Fields

Plain text chunks include a simpler generated_metadata shape:

type: "text"
file_type: "text/plain"
language: Detected language of the text
word_count: Word count for the chunk
file_size: File size in bytes
start_line: Starting line number of the chunk in the source file
num_lines: Number of lines in the chunk

Example

{
  "type": "text",
  "file_type": "text/plain",
  "language": "en",
  "word_count": 57,
  "file_size": 2048,
  "start_line": 0,
  "num_lines": 15
}

Code - Language and Size

For supported source files (e.g., Python, TypeScript, Java, C#), generated_metadata includes:

type: "code"
file_type: One of text/x-python, text/x-script.python, application/typescript, text/typescript, text/x-java-source, text/x-csharp, or application/javascript
language: Detected programming language
word_count: Tokenized word count approximation for code
file_size: File size in bytes
start_line: Starting line number of the chunk in the source file
num_lines: Number of lines in the chunk

Example

{
  "type": "code",
  "file_type": "text/x-python",
  "language": "python",
  "word_count": 120,
  "file_size": 8192,
  "start_line": 0,
  "num_lines": 42
}

PDF - Document Stats

PDF chunks have specialized document-level stats:

type: "pdf"
file_type: "application/pdf"
total_pages: Total number of pages in the document
total_size: Total size of the original file in bytes

Example

{
  "type": "pdf",
  "file_type": "application/pdf",
  "total_pages": 42,
  "total_size": 1048576
}

Image - Dimensions

Image chunks include basic dimensional metadata:

type: "image"
file_type: String (MIME type, e.g., image/jpeg, image/png)
file_size: File size in bytes
width: Image width in pixels
height: Image height in pixels

Example

{
  "type": "image",
  "file_type": "image/jpeg",
  "file_size": 204800,
  "width": 1920,
  "height": 1080
}

Audio - Media Information

Audio chunks include specialized media metadata:

type: "audio"
file_type: String (MIME type, e.g., audio/mpeg, audio/wav)
file_size: File size in bytes
total_duration_seconds: Total duration of the audio in seconds
sample_rate: Audio sample rate in Hz
channels: Number of audio channels
audio_format: Audio format code
bpm: Detected beats per minute (optional, only present when detected)
start_time_seconds: Start time of the chunk in seconds
end_time_seconds: End time of the chunk in seconds
duration_seconds: Duration of the chunk in seconds
chunk_size_bytes: Size of the chunk in bytes

Example

{
  "type": "audio",
  "file_type": "audio/mpeg",
  "file_size": 5242880,
  "total_duration_seconds": 180.5,
  "sample_rate": 44100,
  "channels": 2,
  "audio_format": 1,
  "start_time_seconds": 0,
  "end_time_seconds": 38.93,
  "duration_seconds": 38.93,
  "chunk_size_bytes": 650736
}

Video - Media Information

Video chunks include specialized media metadata:

type: "video"
file_type: String (MIME type, e.g., video/mp4, video/webm)
file_size: File size in bytes
total_duration_seconds: Total duration of the video in seconds
fps: Frames per second
width: Video width in pixels
height: Video height in pixels
frame_count: Total number of frames
has_audio_stream: Whether the video contains an audio track
bpm: Detected beats per minute (optional, only present when detected)
start_time_seconds: Start time of the chunk in seconds
end_time_seconds: End time of the chunk in seconds
duration_seconds: Duration of the chunk in seconds
chunk_size_bytes: Size of the chunk in bytes

Example

{
  "type": "video",
  "file_type": "video/mp4",
  "file_size": 15728640,
  "total_duration_seconds": 120.0,
  "fps": 30.0,
  "width": 1920,
  "height": 1080,
  "frame_count": 3600,
  "has_audio_stream": true,
  "start_time_seconds": 0.0,
  "end_time_seconds": 120.0,
  "duration_seconds": 120.0,
  "chunk_size_bytes": 2097152
}

Type Inference and Flexibility

If type is not present in generated_metadata, it is inferred from file_type when possible.
If neither type nor a recognized file_type is present, the type defaults to "text".
The system may include additional fields as needed for future enhancements; clients should read the documented fields and ignore unknown ones.

Generated Metadata

On this page