sync_bridge - Pounce

asgi.sync_bridge

Sync ASGI bridge — run ASGI apps from a synchronous context.

For simple request-response (no streaming receive, no streaming send), collects the response in memory and returns it as a SyncResponse.

If the app sends more_body=True (streaming) or the scope type is websocket, raises NeedsAsyncError so the caller can hand off to the async pool.

Classes

NeedsAsyncError 0 ▼

Raised when the ASGI app requires async (streaming, WebSocket). The SyncWorker catches this and ha…

Raised when the ASGI app requires async (streaming, WebSocket).

The SyncWorker catches this and hands off the connection to the AsyncPool for multiplexed I/O handling.

SyncResponse 4 ▼

Complete HTTP response from a sync ASGI invocation.

Attributes

Name	Type	Description
`status`	`int`	HTTP status code.
`headers`	`list[tuple[bytes, bytes]]`	Response headers as list of (name, value) byte pairs.
`body`	`bytes`	Full response body bytes.
`needs_async`	`bool`	True if the app indicated streaming (more_body=True).

Functions

call_asgi_sync 4 SyncResponse ▼

Run an ASGI app from a sync context. For simple request-response (no streaming…

def call_asgi_sync(app: ASGIApp, scope: dict[str, Any], body: bytes, *, runner: asyncio.Runner | None = None) -> SyncResponse

Run an ASGI app from a sync context.

For simple request-response (no streaming receive, no streaming send), this collects the response in memory and returns it as a SyncResponse.

If the app sends more_body=True (streaming), sets needs_async=True on the response so the caller can hand off. The response may be partial (headers + first body chunk).

Raises NeedsAsyncError immediately for WebSocket scopes (caller must hand off before invoking the app).

Parameters

Name	Type	Description
`app`	`ASGIApp`	The ASGI application.
`scope`	`dict[str, Any]`	ASGI scope dict.
`body`	`bytes`	Full request body (for non-streaming requests).
`runner`	`asyncio.Runner \| None`	Reusable asyncio.Runner owned by the calling worker thread. Avoids creating/destroying an event loop per request. When None, a temporary Runner is created (slow fallback). Default:`None`

Returns

SyncResponse