Struct ImageBlock 

pub struct ImageBlock { /* private fields */ }

Image content block for vision-capable models.

Supports both URL-based images and base64-encoded images.

Examples

use open_agent::{ImageBlock, ImageDetail};

// From URL
let image = ImageBlock::from_url("https://example.com/image.jpg")?;

// From base64 (use properly formatted base64)
let image = ImageBlock::from_base64("iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==", "image/png")?;

// With detail level
let image = ImageBlock::from_url("https://example.com/image.jpg")?
    .with_detail(ImageDetail::High);

Implementations

impl ImageBlock

pub fn from_url(url: impl Into<String>) -> Result<Self>

Creates a new image block from a URL.

Arguments

• url - The image URL (must be HTTP, HTTPS, or data URI)

Errors

Returns Error::InvalidInput if:

• URL is empty
• URL contains control characters (newline, tab, null, etc.)
• URL scheme is not http://, https://, or data:
• Data URI is malformed (missing MIME type or base64 encoding)
• Data URI base64 portion has invalid characters, length, or padding

Warnings

• Logs a warning to stderr if URL exceeds 2000 characters

Example

use open_agent::ImageBlock;

let image = ImageBlock::from_url("https://example.com/cat.jpg")?;
assert_eq!(image.url(), "https://example.com/cat.jpg");

pub fn from_base64( base64_data: impl AsRef<str>, mime_type: impl AsRef<str>, ) -> Result<Self>

Creates a new image block from base64-encoded data.

Arguments

• base64_data - The base64-encoded image data
• mime_type - The MIME type (e.g., “image/jpeg”, “image/png”)

Errors

Returns Error::InvalidInput if:

• Base64 data is empty
• Base64 contains invalid characters (only A-Z, a-z, 0-9, +, /, = allowed)
• Base64 length is not a multiple of 4
• Base64 has invalid padding (more than 2 ‘=’ characters or not at end)
• MIME type is empty
• MIME type does not start with “image/”
• MIME type contains injection characters (;, \n, \r, ,)

Warnings

• Logs a warning to stderr if base64 data exceeds 10MB (~7.5MB decoded)

Example

use open_agent::ImageBlock;

let base64 = "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==";
let image = ImageBlock::from_base64(base64, "image/png")?;
assert!(image.url().starts_with("data:image/png;base64,"));

pub fn from_file_path(path: impl AsRef<Path>) -> Result<Self>

Creates a new image block from a local file path.

This is a convenience method that reads the file from disk, encodes it as base64, and creates an ImageBlock with a data URI. The MIME type is inferred from the file extension.

Arguments

• path - Path to the image file on the local filesystem

Errors

Returns Error::InvalidInput if:

• File cannot be read
• File extension is missing or unsupported
• File is too large (>10MB warning)

Supported Formats

• .jpg, .jpeg → image/jpeg
• .png → image/png
• .gif → image/gif
• .webp → image/webp
• .bmp → image/bmp
• .svg → image/svg+xml

Example

use open_agent::ImageBlock;

let image = ImageBlock::from_file_path("/path/to/photo.jpg")?;

Security Note

This method reads files from the local filesystem. Ensure the path comes from a trusted source to prevent unauthorized file access.

pub fn with_detail(self, detail: ImageDetail) -> Self

Sets the image detail level.

Example

use open_agent::{ImageBlock, ImageDetail};

let image = ImageBlock::from_url("https://example.com/image.jpg")?
    .with_detail(ImageDetail::High);

pub fn url(&self) -> &str

Returns the image URL (or data URI for base64 images).

pub fn detail(&self) -> ImageDetail

Returns the image detail level.

Trait Implementations

impl Clone for ImageBlock

fn clone(&self) -> ImageBlock

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ImageBlock

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ImageBlock

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for ImageBlock

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.