Strawberry GraphQL @ 0.320.0

Released June 27, 2026 at 11:10 PM GMT+00:00

This release adds support for GraphQL subscriptions over Server-Sent Events (SSE), following the GraphQL over SSE protocol in “distinct connections mode”.

SSE is opt-in. Enable it by including GRAPHQL_SSE_PROTOCOL in your integration’s subscription_protocols :

from strawberry.asgi import GraphQL
from strawberry.subscriptions import (
    GRAPHQL_SSE_PROTOCOL,
    GRAPHQL_TRANSPORT_WS_PROTOCOL,
    GRAPHQL_WS_PROTOCOL,
)
 
app = GraphQL(
    schema,
    subscription_protocols=[
        GRAPHQL_TRANSPORT_WS_PROTOCOL,
        GRAPHQL_WS_PROTOCOL,
        GRAPHQL_SSE_PROTOCOL,
    ],
)

Clients request a stream with Accept: text/event-stream . Queries, mutations, subscriptions, and @defer /@stream are all supported on the async streaming-capable integrations (ASGI, FastAPI, AIOHTTP, Litestar, Quart, Sanic, async Django, and async Channels). See the SSE subscriptions docs for client setup, reconnection, and deployment notes (prefer HTTP/2).

Breaking change: multipart subscriptions are now opt-in. Streaming transports are selected from subscription_protocols , so multipart subscriptions — previously served for any Accept: multipart/mixed request — now require MULTIPART_SUBSCRIPTION_PROTOCOL to be listed there explicitly.

This release was contributed by @patrick91 in https://github.com/strawberry-graphql/strawberry/pull/4466