SanF

A IIIF Image API 3.0 server implementation built with FastAPI, supporting up to Level 2 compliance. It can be used as a standalone server or embedded as a package within an existing FastAPI application.

Features

• GET /iiif/{identifier}/info.json
• GET /iiif/{identifier}/{region}/{size}/{rotation}/{quality}.{format}
• 303 redirect from GET /iiif/{identifier} to info.json
• Level 2 parameters:
  • region: full, square, x,y,w,h, pct:x,y,w,h
  • size: max, w,, ,h, pct:n, w,h, !w,h
  • rotation: 0, 90, 180, 270 (and arbitrary non-negative angles)
  • quality: default
  • format: jpg, png
• CORS enabled (when using create_app, default *)

Installation

pip install sanf

Development Setup

python3.12 -m venv .venv
source .venv/bin/activate
pip install -e .

Running as a Standalone Server

Source images are loaded from ./images by default.

uvicorn sanf.main:create_app --factory --reload

The root directory for the local file connector can be changed via the IIIF_SOURCE_ROOT environment variable.

IIIF_SOURCE_ROOT=/path/to/images uvicorn sanf.main:create_app --factory --reload

Using as a Package

Public API

Symbol	Purpose
IIIFServerSettings	Settings dataclass
create_app(settings)	Creates a standalone FastAPI application
create_iiif_router(settings)	Creates an APIRouter for embedding into an existing application
ImageSourceConnector	Protocol definition for connectors
LocalFileConnector	Connector for local filesystem images
ConnectorError / ImageNotFoundError	Connector exceptions

IIIFServerSettings

from sanf import IIIFServerSettings, LocalFileConnector
from pathlib import Path

settings = IIIFServerSettings(
    connector=LocalFileConnector(root=Path("./images")),
    cors_origins=["https://example.com"],   # default: ["*"]
    jpeg_quality=85,                         # default: 85
    max_width=4096,                          # default: None (no limit)
    max_height=4096,                         # default: None (no limit)
)

create_app — Standalone Application

Returns a complete FastAPI instance including CORS middleware.

from sanf import create_app, IIIFServerSettings, LocalFileConnector
from pathlib import Path

settings = IIIFServerSettings(connector=LocalFileConnector(root=Path("./images")))
app = create_app(settings)

create_iiif_router — Embedding into an Existing Application

Returns an APIRouter without CORS. CORS should be managed by the calling application.

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from sanf import create_iiif_router, IIIFServerSettings, LocalFileConnector
from pathlib import Path

settings = IIIFServerSettings(connector=LocalFileConnector(root=Path("./images")))

app = FastAPI()
app.add_middleware(CORSMiddleware, allow_origins=["*"], allow_methods=["GET"])
app.include_router(create_iiif_router(settings), prefix="/iiif")

Custom Connectors

Any storage backend can be connected by implementing a class that conforms to the ImageSourceConnector protocol.

class MyS3Connector:
    def fetch_image_bytes(self, identifier: str) -> bytes:
        # Return image bytes from S3 or any other backend
        ...

• Raise ImageNotFoundError when the identifier does not exist
• Raise ConnectorError for backend failures
• The identifier is received as a URL-decoded string