Responses API calls build the generation output only from response["choices"],
which Responses payloads do not carry, so Langfuse rendered a blank output.
Fold output[] into one assistant choice (output_text parts concatenated,
function_call and custom_tool_call items as tool_calls) and derive the finish
reason from status when choices are absent. Custom tool call input is now
redacted alongside function call arguments under turn_off_message_logging.
Carries the behavior of #41604 by @moshemorad (issue #41591) onto current
main with typed conversion and single-message output.
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
The v2 LLM span built its output only from response choices, so /v1/embeddings
rendered a Langfuse generation with input, usage and cost but a blank output.
Embedding calls now carry an EmbeddingOutput(count, dimensions) summary that the
Langfuse mapper serializes as the observation output, and they are exported with
the embedding observation type instead of generation. Chat and Responses output
mapping is unchanged.
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Pass-through requests inject the proxy span into upstream headers since #40669, which
replaced an explicit x-pass-traceparent with an unrelated trace and dropped its
x-pass-tracestate. Keep the caller's context when the carrier already names a
different trace, and keep the proxy child span for same-trace or missing headers.
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
The pre-call hook passed the proxy's whole per-request metadata dict into the
request identity, so proxy-owned siblings such as requester_ip_address were
promoted alongside the caller's keys. Only the requester_metadata mapping is
read now, keyed under its wrapper, which keeps the default allowlist behaviour
unchanged
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Strip only the proxy's requester_metadata. wrapper from an allowlisted key so
requester_metadata.trace_id lands as litellm.metadata.trace_id while other
dotted keys keep their full path and cannot collide on a shared leaf name
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
baggage_metadata_keys entries such as requester_metadata.trace_id now resolve the caller's nested metadata.trace_id and stamp it on the LLM-call span as litellm.metadata.trace_id, in both the OTEL v2 logger and the legacy OpenTelemetry callback. Nested metadata mappings are flattened to dotted paths, only allowlisted leaves are promoted, and the requester_metadata blob itself is never promoted
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Pass user_api_key_dict.parent_otel_span into the outgoing W3C injection so the
legacy otel callback propagates its litellm_request span, falling back to the
otel_v2 request root span and then the ambient span. Extend the mapped unit
tests to assert the propagated trace and span ids over real captured headers
for HTTP and WebSocket passthrough with forwarding on and off.
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
CodeQL flagged that TraceControls could be undefined when metadata is imported before payloads. trace_controls now depends only on utils, and the mapping / sequence narrowing parses via pydantic TypeAdapter instead of cast.
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
`langfuse_otel` (OTel v2) only carried `trace_name` from the caller's metadata, so `metadata.trace_user_id` / `session_id` / `tags` (and the `langfuse_trace_user_id` / `langfuse_session_id` proxy headers) never reached Langfuse's user, session and tags fields. Widen the typed caller boundary to `TraceControls`, map it through one `LangfuseMapper.trace_attributes` table on both the root observation and the generation span, and keep `team_id` / `team_alias` proxy-authoritative
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* fix(otel v2): name Langfuse traces from the langfuse_trace_name header or metadata.trace_name
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* test(otel v2): type the named-request helper in the Langfuse logger tests
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
---------
Co-authored-by: yucheng <yucheng@berri.ai>
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
A value length limit clips the input.value blob, so the per-index keys are the
only untruncated copy of a message. Indexing the leading prompt messages dropped
the live user turn from every span attribute on long conversations. Keep message
0 and the most recent turns under the same span-wide budget, original indices
preserved, reply reservation unchanged
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
OpenInferenceMapper spelled every captured prompt and response message out as
two indexed attributes with no bound. A few dozen turns overran the OTel SDK's
128-attribute span limit, which evicts oldest first, so the gen_ai.* model,
provider, usage, cost and finish reason written before it were what got
dropped. Both directions now share one MAX_MESSAGE_ATTRS_PER_SPAN ceiling, the
response keeps at least half of it, and input.value / output.value still carry
the complete conversation
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* fix(otel v2): restore the Datadog auth span and the last-wins callback merge
Move @tracer.wrap() back onto user_api_key_auth so USE_DDTRACE=true emits the
auth span again, and let a failure entry's callback_vars take part in the
destination merge so the resolver picks the same account the runtime parser does
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* test(otel v2): drop docstrings from the two regression tests
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* ci: rerun proxy-infra after the flaky test_check_migration process-tree test
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
---------
Co-authored-by: yucheng <yucheng@berri.ai>
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* feat(otel v2): send a key's or team's whole trace to its own destination
A key or team that configures its own Langfuse, Arize, Weave or New Relic
credentials used to get a single detached span in its account while the rest of
the request trace stayed on the operator's backend, so neither side held a
complete trace. Resolve the destination during auth, forward every span of the
request to it, and hold the same request back from the operator's exporter for
that backend, so the tenant gets the tree the operator would have seen and the
operator gets nothing for that request.
Also let a credential-mandatory preset build without the operator's own env
credentials. Without that, a proxy whose teams each bring their own account fell
back to the legacy integration and never ran a line of the v2 path.
* fix(otel v2): validate tenant destinations and match each backend's own endpoint
Review round on the tenant destination routing.
- A key/team Langfuse host is user-supplied input, so it goes through the
proxy's SSRF guard. A private address is refused, the operator keeps the
trace, and the warning names user_url_allowed_hosts. The operator's own
LANGFUSE_HOST is not checked.
- Arize and Weave destinations now resolve their endpoint and transport
through the backend's own config, so an ARIZE_HTTP_ENDPOINT collector and
a self-hosted WANDB_HOST are honoured instead of the cloud default.
- A half-configured backend no longer resolves: several dynamic header
builders gate each credential separately, so an api key with no space id
produced a non-empty but unusable header set that suppressed the
operator's exporter.
- A callback_type of "failure" no longer takes over the trace. The
destination is resolved during auth, before the outcome is known.
- The fan-out cache evicts without shutting the processor down, matching
ArizePhoenixLogger: a concurrent on_end may still hold it.
- The stdout placeholder is identified by what it does rather than by
equality with an import-time default, so an operator's OTEL_EXPORTER_OTLP_*
collector survives the credential-less path.
* refactor(otel v2): reuse the proxy's own destination allowlist for tenant hosts
A tenant-supplied Langfuse host is the same threat as a URL-valued `model`, so
it now goes through `is_url_destination_allowed_by_host` against
`provider_url_destination_allowed_hosts` instead of a second, DNS-based check
of its own. The DNS lookup would have blocked the asyncio auth path on a
hostname the caller picked, and its cached verdicts could blackhole a real host
after one resolver blip.
Evicting a destination processor now retires it to drain rather than shutting it
down, since `on_end` hands a processor back and exports outside the lock. The
retirees are capped so they cannot accumulate a thread each.
`credential_gated_exporters` tells the synthesized stdout placeholder from a
real exporter by transport rather than by the literal kind `console`, so an
unrecognized kind is not mistaken for a configured collector, and an exporter
the operator did configure survives. That also stops a weave test's env writes
from making this look like a real OTLP exporter later in the same CI worker.
* fix(otel v2): read the tenant's stored callback config the way the sibling parser does
Three divergences between the destination resolver and
`convert_key_logging_metadata_to_callback`, which read the same stored config:
- A key whose callbacks are disabled stores an empty list, and `or` treated that
as "the key configured nothing", so the request inherited the team's
destination. The sibling parser treats an empty list as configured.
- Two entries naming one backend now merge their `callback_vars` last-wins,
matching the sibling, instead of the resolver taking the first entry and the
per-request tracer routing taking the last.
- `credential_gated_exporters` dropped any exporter whose kind had no transport,
which also dropped an `in_memory` exporter the operator asked for. The
placeholder is the spec with every field still at its default, so that is what
the predicate now says.
Arize's `allow_missing_credentials` branch was unreachable: `get_arize_config`
resolves every credential with `os.environ.get` and always supplies an endpoint,
so it never raises. Dropped it and corrected the protocol docstring.
* fix(otel v2): keep the destination merge immutable
The per-backend var merge seeded a plain dict and the gated exporter list a plain
list, both of which the LIT budget counts. Wrap the merge in MappingProxyType and
hand the exporters back as a tuple.
* fix(otel v2): scope the fan-out to its own backend and close shed processors off the export path
Three problems in the fan-out, two of them in the eviction added last round:
- Every v2 logger carries its own provider and emits its own copy of a gen-AI
span, so a proxy running two of them handed the tenant the same model call
twice. A provider now forwards only destinations for the backend it speaks
for; the tenant's own backend always has a logger, since naming it in the key
or team config is what builds one. Reproduced live against a self-hosted
Langfuse on an arize-only proxy and on the bare `otel` callback.
- Eviction could close a processor another thread was still exporting through,
which drops that span. Exports are now counted, and a retired processor is
closed only once its count reaches zero.
- That close ran inside `on_end`, where `shutdown` flushes over the network, so
one unreachable tenant collector stalled every other tenant's spans. It now
runs on a short-lived thread, which also retires the retiree cap: a retiree
drains as soon as its export finishes.
* fix(otel v2): deliver tenant destinations from the published global provider
Scoping the fan-out by callback name in the previous commit left every backend
that is not the canonical logger with a one-span trace: only the published
global provider sees the FastAPI server span, the auth span and the post-call
database spans, so an arize-only proxy handed a team's Langfuse just the model
call. Attach the fan-out once, to that provider, and let it forward every
destination.
An overridden backend now skips per-request tracer routing outright rather than
only clearing its credential headers, since a key or team otel_service_name was
still enough to detach the model call onto a second provider. The destination
carries that service name as a resource attribute instead.
Shed processors drain on a two-thread pool rather than a thread each, so a
tenant cycling its destination config cannot spawn threads as fast as it sends
requests.
* fix(otel v2): drain shed destination processors on daemon workers
A ThreadPoolExecutor joins its workers at interpreter exit, so one unreachable
tenant collector would hold the whole proxy open for its export timeout on the
way down. Two long-lived daemon workers off a queue keep the thread count
bounded without blocking shutdown.
* fix(otel v2): give the fan-out its own drain pool instead of a lazy singleton
functools.lru_cache does not hold a lock across the call it caches, so
concurrent first evictions each finish building a queue and start its
workers, and every queue but the winner is abandoned with two daemon
threads blocked on it forever.
* fix(otel v2): close no destination processor under a span still in flight
The fan-out now refuses new work once shutdown starts and waits out the
spans already being forwarded, so teardown neither drops a trace mid-forward
nor hands the next caller an exporter nothing will ever close. The wait is
bounded so a dead collector cannot hold the proxy open.
* fix(otel v2): retire the drain workers with the fan-out that started them
A proxy that rebuilds its telemetry builds another fan-out, so workers that
outlive the one that started them are two more threads per reload. Shutdown
now retires them once everything queued is closed, and a processor shed
afterwards is closed inline rather than queued to nobody.
* fix(otel v2): guard the fan-out's closed state with the lock that gates it
An Event read on its own leaves room for shutdown to run in the gap. A cache
miss then inserted a live exporter into a map that had been cleared, and a
shed processor landed behind sentinels every drain worker had exited on.
The drain pool takes its queue by injection so both interleavings are
reachable from a test without patching.
* feat(otel v2): let a tenant destination export alongside the operator's own
Override stays the default: a key or team destination replaces the operator's
exporter for that backend. Operators running one org-wide backend across every
team set litellm_settings.otel_tenant_destination_mode to additive, and the
same trace lands in both places. A team that names the operator's own project
is still written once, since the fan-out skips a destination the operator's
exporter is already sending that span to.
* fix(otel v2): let a straggling export close its own destination processor
Shutdown waits out the exports in flight, but the wait has to be bounded or a
tenant collector that stops answering holds the proxy open on the way down.
Past the bound it closed everything anyway, which is the case it was written to
avoid: a processor closed under the span it is carrying loses that span.
Keep the bound and retire the stragglers instead. The thread still exporting one
closes it through the drain as soon as its export returns, so teardown stays
bounded and no span is dropped mid-forward.
* fix(otel v2): identify a destination account by its credentials, not its header names
Under additive the fan-out skips a destination the operator's own exporter
already writes to, so the same account is not written twice. It compared header
names as well as values, and one account answers to more than one spelling:
the operator's Arize exporter sends space_id where a team destination sends
arize-space-id, so every span landed in the operator's own space twice.
The credentials are the identity. Compare those and leave the spelling to each
backend.
* fix(otel v2): keep the credential's role in a destination's account identity
Comparing values alone folds two accounts together whenever they hold the same
strings in different roles, and the second team would then get no trace at all.
Compare the credential under a normalized name instead, and fold the one alias
that actually exists: Arize's space_id and arize-space-id.
* fix(otel v2): build one destination processor per destination, not per racing span
Building outside the cache lock meant a cold cache met by a burst of concurrent
requests constructed an exporter per thread, kept one, and handed the rest to the
drain, so a batch worker and a connection pool per losing thread sat in a queue
two workers service.
Build under the lock that reads the cache. Opening an exporter connects to
nothing, so the lock is held for a constructor, once per destination, and the
race it was avoiding stops existing.
* fix(otel v2): bound the teardown that closes a destination, not the one that never blocks
The five-second bound guarded the wait for spans still inside on_end, but a
batching processor's on_end only queues the span and returns, so that counter is
empty and the bound engaged against nothing. The blocking half was the serial
close, which flushes over the network and joins the SDK's own worker thread with
no timeout of its own, so a single tenant collector that answers and never
finishes held process teardown open for as long as it liked.
Hand every close to the drain, whose workers are daemons, and give the whole
teardown one deadline.
* fix(otel v2): preserve operator spans on destination failure
* fix(otel v2): anchor destinations off the published provider, refuse headerless tenant transports
set_tracer_provider keeps the first provider it is handed, so a process whose
OTel global was claimed before the proxy published (auto-instrumentation, a
legacy logger) had no fan-out on the global and auth anchored no destination.
Auth now reads the fan-out off the registered logger's own provider.
A destination whose protocol maps to a headerless exporter kind is no longer
buildable: the console fallback would drop the tenant's credentials and print
the spans to stdout while the operator's exporter stood down for them.
* fix(otel): anchor tenant fan-out to the published provider
A legacy v1 logger can occupy proxy_server.open_telemetry_logger, in which case
the proxy publishes with registered=None and the fan-out lands on a v2 logger
taken from _in_memory_loggers. Reading the registered slot found no v2 logger
and the OTel global belonged to v1, so auth refused every tenant destination.
* fix(otel): preserve registered provider fallback
* test(otel): cover pre-publish provider fallback
* fix(otel): attach fan-out on fallback provider
* fix(otel): serialize first fan-out attach
* fix(otel): keep the operator's database endpoint out of tenant traces
A database span forwarded to a key or team destination carried the proxy's own
Postgres host, port and schema, and on failure the Prisma error text naming them.
The fan-out now hands tenants a view of each database span without those keys,
its events or its status text, while the operator's own copy is untouched and
model endpoints such as server.address on the LLM span still travel
* fix(otel): keep relabelled spans in the fan-out and honour disabled callbacks for destinations
A key or team otel_service_name used to move a backend's span onto a second
provider even when another backend had a destination, so the fan-out never saw
the model call and the tenant's trace lost it. A service name alone now stays on
the published provider whenever the request has a destination; credential and
project routing to a tenant's own account is unchanged
Destinations now skip a backend the request disabled dynamically, reading the
x-litellm-disable-callbacks header and the key's litellm_disabled_callbacks with
the same precedence and premium gate dispatch applies, so a disabled backend is
neither delivered to nor withheld from the operator
* test(otel): project routing survives a sibling backend destination
* docs(otel): state why a disabled backend still routes its own span
* fix(otel): keep a degraded backend's spans off a collector another v2 logger already serves
* test(otel): a credentialed preset beside another v2 logger keeps every exporter
* fix(otel): keep credentialless fallback on base path
* test(otel): cover legacy callback carrier rejection
* fix(otel): preserve valid exporter beside gated preset
* fix(otel): avoid console export without operator destination
* refactor(otel): share the console placeholder check with the presets
* fix(otel): bound shed destination processors waiting on a dead collector
* fix(otel): preserve explicit console exporters
* fix(otel): avoid mutable field-set construction
* fix(otel): close drain saturation race
* fix(otel): drop captured request headers from tenant spans
* test(otel v2): give the newrelic dispatch tests operator credentials, since a credential-less preset now falls back
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* fix(otel): rebuild an anchored destination's processor past drain saturation
A destination deliverable() accepted at auth can be evicted by other tenants' auths
before its request's spans end, and that eviction is what tips the drain over. The
saturation gate then refused the rebuild at on_end, and with the operator's exporter
already stood down for that backend the span went nowhere. The gate now applies only
while a request decides whether to anchor
* fix(otel): hold destination eviction while the drain is saturated
An anchored destination evicted by other tenants' auths is rebuilt on its
next span, and that rebuild evicted another anchored one, so with more
destinations in flight than the cache holds every span cost one more
processor, one more batch thread and one more close queued behind a collector
that never answers. Eviction now holds while the drain is saturated, so the
cache keeps one entry per destination in flight and trims back to its cap on
the next hit or build once the drain has room
* fix(otel): keep the proxy's own error text out of tenant traces
A tenant destination received every span the request produced, error text
included, so a Prisma failure during auth handed a team admin's collector the
operator's Postgres endpoint, and the exception event on any failed span carried
a stack trace naming the proxy's install paths.
Spans the tenant's own call produced (the model call, MCP, guardrails) keep their
error text. Every other span keeps the failure without the prose: its type, its
provider error code and its status code, with the message, the events and the
status description dropped. Stack traces come off every span, attribute and event
alike.
A destination's resource attributes now merge onto the span's resource instead of
rebuilding one per span, which was re-running resource detection on every export.
* fix(otel): redact tenant URL query parameters
* fix(otel): close final tenant routing gaps
* fix(otel): refresh destinations for stateful MCP messages
---------
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* feat(otel): add http/json export protocol for OTel v2 traces
OTEL_EXPORTER_OTLP_PROTOCOL=http/json was accepted but routed to the protobuf
OTLP/HTTP exporter, so collectors that only decode JSON rejected every batch.
Route it to an OTLP/JSON span exporter that reuses the SDK HTTP transport and
expose the protocol as a select field on the OpenTelemetry callback in the
admin UI.
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* refactor(otel): walk the fixed OTLP shape instead of recursing when hex-encoding ids
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* fix(ui): map stored callback variables onto their form fields when editing a callback
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
---------
Co-authored-by: yassin <yassin@berri.ai>
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Add traces_endpoint (env OTEL_TRACES_ENDPOINT / OTEL_EXPORTER_OTLP_TRACES_ENDPOINT, per-exporter key traces_endpoint, Admin UI field) as a complete OTLP/HTTP trace URL used verbatim, so collectors that do not serve /v1/traces can receive traces. endpoint keeps its existing base-URL + signal-path normalization.
Resolves LIT-7218
Co-authored-by: yassin <yassin@berri.ai>
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* feat(otel): stamp litellm.request.route on the LLM call span
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* refactor(otel): drop redundant comment on REQUEST_ROUTE
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* style(otel): Final-annotate route test locals, drop field comment
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* fix(otel): read litellm.request.route off the server span
The LLM call span took the auth-normalized literal path from logging
metadata, which disagrees with the SERVER span wherever FastAPI matched a
template: on /engines/{model:path}/chat/completions the LLM span spelled the
model name while http.route carried the template, so the two spans grouped
into different buckets and the PR's premise did not hold.
Read the value off the span that already holds it. The request's root SERVER
span is anchored per request for parenting, and its attributes stay readable
after it ends, so request_root_http_route() answers from the async close
callback with the same http.route the SERVER span exports: the route template
on a normal route, the literal path where the passthrough hook rewrote it, and
the mount point on an MCP call. Nothing has to re-derive any of that, so the
two spans cannot drift apart.
The route the proxy recorded at auth stays as the backstop for a deployment
whose FastAPI instrumentation never mounted, where there is no server span to
disagree with. Off the proxy the attribute is omitted rather than empty.
---------
Co-authored-by: shivam <shivam@berri.ai>
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Yucheng He <yucheng@berri.ai>
* fix(otel): emit cache token counts on OTel v2 LLM spans
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* fix(otel): trim comment in LLMUsage adapter
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* fix(otel): drop casts in LLMUsage cache token adapter
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* fix(deps): bump restrictedpython to 8.3 for GHSA-ffg3-p8fm-mjx2
Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
---------
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
* fix(otel/v2): detach credential-routed tenant spans into their own trace
Multi-tenant OTel v2 routes a team or key's LLM-call span to that tenant's
own vendor account (New Relic, Arize, Langfuse, Weave) via dynamic OTLP
credential headers, while the request-root, auth, and db spans stay on the
operator's default backend. The span was still parented into the request
trace, so the tenant account received a child whose parent it never got,
and New Relic rendered it as a fragmented trace with a missing parent.
Detach a credential-routed span the same way a project-routed (Phoenix)
span already detaches: root a fresh trace in the tenant account and link
back to the request trace for correlation. Service-name routing keeps
parenting, since it only relabels service.name on the same operator
backend where the parent is present.
Guard the detach on the callback actually owning an OTLP exporter the
credentials can reach: a callback owning only a console or in_memory
exporter has nowhere to stamp them, so the span would export to the
default backend unchanged and detaching would orphan it on the very
backend that holds its parent. In that case warn once and keep the
default tracer.
* fix(otel/v2): derive tenant-route routability from resolved exporter transport
A denylist classified an owned exporter as routable whenever its kind was
not console/in_memory, so a typo'd or unavailable kind (e.g. "otlp",
"grcp") passed the check while _exporter_from_spec falls it back to a
header-ignoring console exporter. Detaching such a span would root a fresh
trace that only ever reaches the operator console, never the tenant
backend, orphaning it on both sides.
Route on a shared exporter_transport() predicate that resolves the kind the
same way _exporter_from_spec builds it (registered factories + otlp_http
aliases -> http, otlp_grpc aliases -> grpc, else headerless), so an
unresolvable kind is headerless and stays parented. Fixes the same latent
gap in project routability.
Under otel_v2, a client that propagates W3C trace context in params._meta
(SEP-414) pulled the tools/call span out of the gateway's trace:
resolve_mcp_span_context parented the MCP span to the client's remote
context and demoted the gateway's own transport span to a span link. The
gateway's tracing backend only ever receives the gateway's half of such a
trace, so the span was unreachable from the trace view and the POST
transaction showed a dangling link.
Invert the anchoring: the MCP tool-call and tools/list spans now always
nest under the transport span of the request carrying the message, and the
client's propagated context is recorded as the span link instead, so the
correlation survives while every trace stays renderable. With no transport
at all the span roots its own trace and still carries the link, keeping a
single shape for the event. Both returned contexts are built on an
explicitly empty base so ambient session state can never leak in, and the
span inherits the transport's sampling decision like every other
request-level span.
