Custom Contentviews

Contentviews pretty-print binary message data (e.g. HTTP response bodies) that would otherwise be hard to understand for humans. Some contentviews are also interactive, i.e. the pretty-printed representation can be edited and mitmproxy will re-encode it into a binary message.

Simple Example

All contentviews implement the Contentview base class:

from mitmproxy import contentviews


class SwapCase(contentviews.Contentview):
    def prettify(self, data: bytes, metadata: contentviews.Metadata) -> str:
        return data.swapcase().decode()

    def render_priority(self, data: bytes, metadata: contentviews.Metadata) -> float:
        if metadata.content_type and metadata.content_type.startswith("text/example"):
            return 2  # return a value > 1 to make sure the custom view is automatically selected
        else:
            return 0


contentviews.add(SwapCase)

To use this contentview, load it as a regular addon:

mitmproxy -s examples/addons/contentview.py

Like all other mitmproxy addons, contentviews are hot-reloaded when their file contents change. mitmproxy (but not mitmweb) will automatically re-render the contentview as well.

For more details, see the mitmproxy.contentviews API documentation.

Syntax Highlighting

Contentviews always return an unstyled str, but they can declare that their output matches one of the predefined SyntaxHighlight formats. In particular, binary formats may prettify to YAML (or JSON) and use the YAML highlighter.

The list of supported formats is currently limited, but the implementation is based on tree-sitter and easy to extend (see the mitmproxy-highlight crate).

Interactive Contentviews

The following example implements an interactive contentview that allows users to perform edits on the prettified representation:

from mitmproxy import contentviews


class InteractiveSwapCase(contentviews.InteractiveContentview):
    def prettify(
        self,
        data: bytes,
        metadata: contentviews.Metadata,
    ) -> str:
        return data.swapcase().decode()

    def reencode(
        self,
        prettified: str,
        metadata: contentviews.Metadata,
    ) -> bytes:
        return prettified.encode().swapcase()


contentviews.add(InteractiveSwapCase)