Page reader

Add a reader, OCR engine, or vision model that joins the generic routing ladder through its descriptor kind.

A generic reader implements the PageReader protocol and advertises the kind that determines its place in the routing ladder. This example is a CPU OCR lane; read_with_engine() stands for your code, and everything facing indx uses the real public contracts. Package and install it as the overview describes.

from typing import Any

from indx_interfaces import (
    BlockStatus,
    CapabilityDescriptor,
    CapabilityId,
    CapabilityKind,
    Device,
    PageOutput,
)

CAPABILITY_ID = CapabilityId("acme-ocr")

class Reader:
    def read(
        self, content: bytes, media_type: str, pages: tuple[int, ...]
    ) -> tuple[PageOutput, ...]:
        outputs = []
        for page in pages:
            try:
                text, metadata = read_with_engine(content, media_type, page)
                outputs.append(PageOutput(page=page, text=text, metadata=metadata))
            except Exception as error:
                outputs.append(
                    PageOutput(
                        page=page,
                        status=BlockStatus.FAILED,
                        reason=str(error),
                    )
                )
        return tuple(outputs)

class Provider:
    def descriptors(self) -> tuple[CapabilityDescriptor, ...]:
        return (
            CapabilityDescriptor(
                id=CAPABILITY_ID,
                version="1",
                kind=CapabilityKind.OCR,
                devices=(Device.CPU,),
                media_types=("application/pdf",),
                available=True,
            ),
        )

    def create(self, capability_id: CapabilityId) -> Any:
        if capability_id != CAPABILITY_ID:
            raise ValueError(f"unknown capability: {capability_id}")
        return Reader()

Import heavy runtimes inside create(), read(), or a lazily imported implementation module. Discovery calls descriptors() while building every snapshot and must not load weights, initialize a GPU, or contact a service.

Page reader

Reference

Developer