Context propagation¶

Your service was handed a request carrying x-request-id: rid-1. servicewright's transports bind that id — and the user, tenant and trace ids next to it — into its request context for the whole unit of work. Every outgoing call that request makes should carry the same ids, or the trail stops at your service.

clientwright[servicewright] wires that. servicewright's propagation_metadata already satisfies the HeaderProvider protocol as it is; the contrib module names the join so no service writes it by hand.

Wiring it¶

from clientwright import AdapterDeps, ClientConfig, build
from clientwright.contrib.servicewright import servicewright_headers

deps = AdapterDeps(header_providers=servicewright_headers())
client = build("httpx", ClientConfig(service_name="orders"), deps)

# inside a unit of work the transport has bound (or your own bind_context block):
await client.get("/inventory")  # x-request-id, x-user-id, x-tenant-id, x-trace-id

Only the ids actually bound travel: outside any bound context the provider returns nothing and the request goes out unchanged. A header the caller set explicitly is never overwritten — providers fill in what is missing.

Composing¶

servicewright_headers() returns the providers tuple rather than a whole AdapterDeps, so it sits next to everything else you inject:

from clientwright.adapters.observability import PrometheusClientMetrics
from clientwright.contrib.deadline import AmbientDeadlineSource
from clientwright.contrib.servicewright import servicewright_headers

deps = AdapterDeps(
    metrics=PrometheusClientMetrics(),
    header_providers=servicewright_headers(),
    deadline_source=AmbientDeadlineSource(),
)

Your own providers go in the same tuple: (*servicewright_headers(), my_provider).

A different header mapping¶

propagation_metadata takes a {context_key: header_name} mapping; the helper uses servicewright's standard one. For another, build the tuple yourself:

from functools import partial

from servicewright import propagation_metadata

deps = AdapterDeps(header_providers=(partial(propagation_metadata, {"request_id": "X-Correlation-ID"}),))

Why an extra¶

Unlike contrib.deadline, this module imports servicewright at import time — the real function is the point, there is nothing structural to type — so a missing extra fails at import clientwright.contrib.servicewright with an install hint. The extra pins servicewright>=0.1,<1; the export has not changed since 0.1.0.