diff --git a/weave/trace_server/base64_content_conversion.py b/weave/trace_server/base64_content_conversion.py
index 8f50eef7da17..14c0f1aa3300 100644
--- a/weave/trace_server/base64_content_conversion.py
+++ b/weave/trace_server/base64_content_conversion.py
@@ -9,7 +9,6 @@
 import re
 from typing import Any, TypeVar
 
-import ddtrace
 
 from weave.trace_server.trace_server_interface import (
     CallEndReq,
@@ -20,6 +19,7 @@
     TraceServerInterface,
 )
 from weave.type_wrappers.Content.content import Content
+from weave.trace_server.tracing import traced
 
 logger = logging.getLogger(__name__)
 
@@ -66,7 +66,7 @@ def is_data_uri(data_uri: str) -> bool:
     return DATA_URI_PATTERN.match(data_uri) is not None
 
 
-@ddtrace.tracer.wrap(name="store_content_object")
+@traced(name="store_content_object")
 def store_content_object(
     content_obj: Content,
     project_id: str,
diff --git a/weave/trace_server/clickhouse/utilities.py b/weave/trace_server/clickhouse/utilities.py
index f0a4039ca03c..8149aabe9e85 100644
--- a/weave/trace_server/clickhouse/utilities.py
+++ b/weave/trace_server/clickhouse/utilities.py
@@ -12,7 +12,6 @@
 from collections.abc import Sequence
 from typing import Any, TypeVar, cast
 
-import ddtrace
 import sqlparse
 from clickhouse_connect.driver.client import Client as CHClient
 from clickhouse_connect.driver.exceptions import DatabaseError
@@ -23,6 +22,7 @@
 from weave.trace_server.datadog import set_current_span_dd_tags
 from weave.trace_server.errors import InsertTooLarge
 from weave.trace_server.kafka import KafkaProducer
+from weave.trace_server.tracing import traced
 
 logger = logging.getLogger(__name__)
 
@@ -380,7 +380,7 @@ def maybe_enqueue_minimal_call_end(
 # ---------------------------------------------------------------------------
 
 
-@ddtrace.tracer.wrap(name="clickhouse_trace_server_batched.find_call_descendants")
+@traced(name="clickhouse_trace_server_batched.find_call_descendants")
 def find_call_descendants(
     root_ids: list[str],
     all_calls: list[tsi.CallSchema],
diff --git a/weave/trace_server/eval_results_helpers.py b/weave/trace_server/eval_results_helpers.py
index 735293f02b59..a4f5124f53c2 100644
--- a/weave/trace_server/eval_results_helpers.py
+++ b/weave/trace_server/eval_results_helpers.py
@@ -13,7 +13,6 @@
 from collections.abc import Callable, Iterable
 from typing import Any
 
-import ddtrace
 from pydantic import ValidationError
 
 from weave.shared import refs_internal as ri
@@ -22,6 +21,7 @@
 from weave.trace_server import trace_server_common as tsc
 from weave.trace_server import trace_server_interface as tsi
 from weave.trace_server.errors import InvalidRequest
+from weave.trace_server.tracing import traced
 
 _SUPPORTED_SORT_PREFIXES = (
     "scores.",
@@ -367,7 +367,7 @@ def _build_trial(
     )
 
 
-@ddtrace.tracer.wrap(name="eval_results_helpers.build_eval_rows_from_calls")
+@traced(name="eval_results_helpers.build_eval_rows_from_calls")
 def build_eval_rows_from_calls(
     predict_and_score_calls: list[tsi.CallSchema],
     child_by_parent: dict[str, list[tsi.CallSchema]],
@@ -433,7 +433,7 @@ def finalize_rows(
     return apply_row_selection(rows, eval_root_ids, require_intersection, offset, limit)
 
 
-@ddtrace.tracer.wrap(name="eval_results_helpers.build_eval_rows")
+@traced(name="eval_results_helpers.build_eval_rows")
 def build_eval_rows(
     page_calls: list[tsi.CallSchema],
     eval_root_ids: list[str],
@@ -542,7 +542,7 @@ def resolve_eval_row_refs(
     return []
 
 
-@ddtrace.tracer.wrap(name="eval_results_helpers.eval_results_grouped_rows")
+@traced(name="eval_results_helpers.eval_results_grouped_rows")
 def eval_results_grouped_rows(
     req: tsi.EvalResultsQueryReq,
     eval_root_ids: list[str],
@@ -576,7 +576,7 @@ def eval_results_grouped_rows(
     )
 
 
-@ddtrace.tracer.wrap(name="eval_results_helpers.fetch_eval_root_metadata")
+@traced(name="eval_results_helpers.fetch_eval_root_metadata")
 def fetch_eval_root_metadata(
     server: tsi.TraceServerInterface,
     project_id: str,
@@ -618,7 +618,7 @@ def validate_eval_results_request(req: tsi.EvalResultsQueryReq) -> None:
                 )
 
 
-@ddtrace.tracer.wrap(name="eval_results_helpers.eval_results_query")
+@traced(name="eval_results_helpers.eval_results_query")
 def eval_results_query(
     server: tsi.TraceServerInterface,
     req: tsi.EvalResultsQueryReq,
@@ -744,7 +744,7 @@ def _process_scorer_output(
             )
 
 
-@ddtrace.tracer.wrap(name="eval_results_helpers.compute_summary_from_rows")
+@traced(name="eval_results_helpers.compute_summary_from_rows")
 def compute_summary_from_rows(
     rows: list[tsi.EvalResultsRow],
     eval_call_metadata: dict[str, dict[str, Any]] | None = None,
diff --git a/weave/trace_server/kafka.py b/weave/trace_server/kafka.py
index dd9bd9a6c839..012e64bcdc3b 100644
--- a/weave/trace_server/kafka.py
+++ b/weave/trace_server/kafka.py
@@ -2,7 +2,6 @@
 import socket
 from typing import Any
 
-import ddtrace
 from confluent_kafka import (
     Consumer as ConfluentKafkaConsumer,
 )
@@ -26,6 +25,7 @@
     kafka_client_user,
     kafka_producer_max_buffer_size,
 )
+from weave.trace_server.tracing import traced
 
 CALL_ENDED_TOPIC = "weave.call_ended"
 SCORE_CALLS_TOPIC = "weave.score_calls"
@@ -149,7 +149,7 @@ def produce_score_calls(
         if flush_immediately:
             self.flush(0)
 
-    @ddtrace.tracer.wrap(name="kafka_producer.produce_score_agent_spans")
+    @traced(name="kafka_producer.produce_score_agent_spans")
     def produce_score_agent_spans(self, event: ScoreAgentSpansEvent) -> None:
         """Produce a weave.score_agent_spans event to Kafka.
 
diff --git a/weave/trace_server/parallel_bucket_uploads.py b/weave/trace_server/parallel_bucket_uploads.py
index 40cbd745e864..9a5530f67b77 100644
--- a/weave/trace_server/parallel_bucket_uploads.py
+++ b/weave/trace_server/parallel_bucket_uploads.py
@@ -44,7 +44,6 @@
 from concurrent.futures import ThreadPoolExecutor, as_completed
 from dataclasses import dataclass
 
-import ddtrace
 
 from weave.trace_server import clickhouse_trace_server_settings as ch_settings
 from weave.trace_server import trace_server_interface as tsi
@@ -57,6 +56,7 @@
     key_for_project_digest,
     store_in_bucket,
 )
+from weave.trace_server.tracing import traced
 
 logger = logging.getLogger(__name__)
 
@@ -129,7 +129,7 @@ def has(self, project_id: str, digest: str) -> bool:
     def __bool__(self) -> bool:
         return bool(self._pending)
 
-    @ddtrace.tracer.wrap(name="bucket_upload_batch.flush")
+    @traced(name="bucket_upload_batch.flush")
     def flush(
         self, client: FileStorageClient | None
     ) -> list[FileChunkCreateCHInsertable]:
diff --git a/weave/trace_server/project_version/clickhouse_project_version.py b/weave/trace_server/project_version/clickhouse_project_version.py
index af246e960ae3..4893993c5577 100644
--- a/weave/trace_server/project_version/clickhouse_project_version.py
+++ b/weave/trace_server/project_version/clickhouse_project_version.py
@@ -2,17 +2,18 @@
 
 import logging
 
-import ddtrace
 from clickhouse_connect.driver.client import Client as CHClient
 
 from weave.trace_server.calls_query_builder.utils import param_slot
 from weave.trace_server.orm import ParamBuilder
 from weave.trace_server.project_version.types import ProjectDataResidence
+from weave.trace_server.tracing import traced
+from opentelemetry import trace
 
 logger = logging.getLogger(__name__)
 
 
-@ddtrace.tracer.wrap(name="clickhouse_project_version.get_project_data_residence")
+@traced(name="clickhouse_project_version.get_project_data_residence")
 def get_project_data_residence(
     project_id: str, ch_client: CHClient
 ) -> ProjectDataResidence:
@@ -43,9 +44,11 @@ def get_project_data_residence(
         has_complete = row[0]
         has_merged = row[1]
 
-        root_span = ddtrace.tracer.current_root_span()
-        if root_span:
-            root_span.set_tags({"has_complete": has_complete, "has_merged": has_merged})
+        root_span = trace.get_current_span()
+        if root_span.is_recording():
+            root_span.set_attributes(
+                {"has_complete": has_complete, "has_merged": has_merged}
+            )
 
         if has_complete and has_merged:
             return ProjectDataResidence.BOTH
diff --git a/weave/trace_server/project_version/project_version.py b/weave/trace_server/project_version/project_version.py
index 56da433bd0ca..400f6020d99b 100644
--- a/weave/trace_server/project_version/project_version.py
+++ b/weave/trace_server/project_version/project_version.py
@@ -1,7 +1,6 @@
 import logging
 import threading
 
-import ddtrace
 from cachetools import LRUCache
 from clickhouse_connect.driver.client import Client as CHClient
 
@@ -18,6 +17,7 @@
     ReadTable,
     WriteTarget,
 )
+from weave.trace_server.tracing import _tracer  # noqa: PLC2701
 
 logger = logging.getLogger(__name__)
 
@@ -60,7 +60,7 @@ def _get_residence(
 
         # Only span the cache-miss path. Cache-hit calls are extremely high
         # volume and produce noisy DD spans with no useful information.
-        with ddtrace.tracer.trace("table_routing.fetch_residence"):
+        with _tracer.start_as_current_span("table_routing.fetch_residence"):
             residence = get_project_data_residence(project_id, ch_client)
 
             set_root_span_dd_tags({"project_version.fetch_residence": residence.value})
diff --git a/weave/trace_server/ttl_settings.py b/weave/trace_server/ttl_settings.py
index 45912d89a27d..f6649fc4d1ca 100644
--- a/weave/trace_server/ttl_settings.py
+++ b/weave/trace_server/ttl_settings.py
@@ -18,13 +18,13 @@
 import logging
 import threading
 
-import ddtrace
 import redis
 from cachetools import TTLCache
 from clickhouse_connect.driver.client import Client as CHClient
 
 from weave.trace_server.datadog import set_current_span_dd_tags
 from weave.trace_server.redis_client import get_redis_client
+from weave.trace_server.tracing import _tracer, traced  # noqa: PLC2701
 
 logger = logging.getLogger(__name__)
 
@@ -66,18 +66,18 @@ def get_project_retention_days(
         set_current_span_dd_tags({"ttl.cache_hit": "L1"})
         return cached
 
-    with ddtrace.tracer.trace("ttl_settings.get_project_retention_days") as span:
+    with _tracer.start_as_current_span("ttl_settings.get_project_retention_days") as span:
         redis_client = get_redis_client()
         if redis_client is not None:
             redis_val = _l2_get(redis_client, project_id)
             if redis_val is not None:
                 _l1_set(project_id, redis_val)
-                span.set_tag("ttl.cache_hit", "L2")
+                span.set_attribute("ttl.cache_hit", "L2")
                 return redis_val
 
         retention_days = _query_clickhouse(ch_client, project_id)
-        span.set_tag("ttl.cache_hit", "clickhouse")
-        span.set_tag("ttl.retention_days", retention_days)
+        span.set_attribute("ttl.cache_hit", "clickhouse")
+        span.set_attribute("ttl.retention_days", retention_days)
 
         if redis_client is not None:
             _l2_set(redis_client, project_id, retention_days)
@@ -179,7 +179,7 @@ def _l2_delete(redis_client: redis.Redis, project_id: str) -> None:
         logger.exception("Redis L2 cache delete failed for project %s", project_id)
 
 
-@ddtrace.tracer.wrap(name="ttl_settings.query_clickhouse")
+@traced(name="ttl_settings.query_clickhouse")
 def _query_clickhouse(ch_client: CHClient, project_id: str) -> int:
     """Query ClickHouse for the latest retention_days via argMax.
 
diff --git a/weave/trace_server/usage_utils.py b/weave/trace_server/usage_utils.py
index f481b125a424..239a84a176ae 100644
--- a/weave/trace_server/usage_utils.py
+++ b/weave/trace_server/usage_utils.py
@@ -5,9 +5,9 @@
 from collections.abc import Iterable
 from typing import Any
 
-import ddtrace
 
 from weave.trace_server import trace_server_interface as tsi
+from weave.trace_server.tracing import traced
 
 
 @dataclasses.dataclass(frozen=True)
@@ -17,7 +17,7 @@ class UsageCall:
     summary: dict[str, Any] | None
 
 
-@ddtrace.tracer.wrap(name="usage_utils.aggregate_usage_with_descendants")
+@traced(name="usage_utils.aggregate_usage_with_descendants")
 def aggregate_usage_with_descendants(
     calls: Iterable[UsageCall],
     include_costs: bool,
diff --git a/weave/trace_server/workers/evaluate_model_worker/evaluate_model_worker.py b/weave/trace_server/workers/evaluate_model_worker/evaluate_model_worker.py
index 660d97dab658..b488b7de7518 100644
--- a/weave/trace_server/workers/evaluate_model_worker/evaluate_model_worker.py
+++ b/weave/trace_server/workers/evaluate_model_worker/evaluate_model_worker.py
@@ -1,7 +1,6 @@
 import asyncio
 from abc import ABC, abstractmethod
 
-import ddtrace
 
 import weave
 from weave.evaluation.eval import Evaluation
@@ -13,6 +12,7 @@
     LLMStructuredCompletionModel,
 )
 from weave.trace_server.trace_server_interface import EvaluateModelArgs
+from weave.trace_server.tracing import traced
 
 EVALUATE_MODEL_WORKER_MARKER = {"_weave_eval_meta": {"evaluate_model_worker": True}}
 
@@ -34,7 +34,7 @@ def evaluate_model(args: EvaluateModelArgs) -> None:
     _evaluate_model(args)
 
 
-@ddtrace.tracer.wrap(name="evaluate_model_worker.evaluate_model")
+@traced(name="evaluate_model_worker.evaluate_model")
 def _evaluate_model(args: EvaluateModelArgs) -> None:
     # This worker reconstructs user-supplied objects; it must never deserialize
     # code-bearing custom objects (Op / load_op). The secure client locks the decode
@@ -51,7 +51,7 @@ def _evaluate_model(args: EvaluateModelArgs) -> None:
     _run_evaluation(loaded_evaluation, loaded_model, args.evaluation_call_id)
 
 
-@ddtrace.tracer.wrap(name="evaluate_model_worker.evaluate_model.get_valid_evaluation")
+@traced(name="evaluate_model_worker.evaluate_model.get_valid_evaluation")
 def _get_valid_evaluation(client: WeaveClient, evaluation_ref: str) -> Evaluation:
     loaded_evaluation = client.get(Ref.parse_uri(evaluation_ref))
 
@@ -73,7 +73,7 @@ def _get_valid_evaluation(client: WeaveClient, evaluation_ref: str) -> Evaluatio
     return loaded_evaluation
 
 
-@ddtrace.tracer.wrap(name="evaluate_model_worker.evaluate_model.get_valid_model")
+@traced(name="evaluate_model_worker.evaluate_model.get_valid_model")
 def _get_valid_model(
     client: WeaveClient, model_ref: str
 ) -> LLMStructuredCompletionModel:
@@ -87,7 +87,7 @@ def _get_valid_model(
     return loaded_model
 
 
-@ddtrace.tracer.wrap(name="evaluate_model_worker.evaluate_model.run_evaluation")
+@traced(name="evaluate_model_worker.evaluate_model.run_evaluation")
 def _run_evaluation(
     loaded_evaluation: Evaluation,
     loaded_model: LLMStructuredCompletionModel,