Add OTel exporter for weave + example config

docs/source/run-workflows/observe/observe-workflow-with-weave.md

@@ -194,8 +194,66 @@ def my_auth_callback(request):
     context.metadata.trace_user_email = user_info.get("email")
 ```
 
+## OTel-Based Exporter
+
+Weave also supports an [OTel-based integration](https://weave-docs.wandb.ai/guides/tracking/otel) that sends traces via OpenTelemetry. This uses the `opentelemetry` plugin instead of the `weave` plugin, which means it does not require installing `weave` as a dependency — only the `opentelemetry` extra is needed.
+
+### Install the OTel plugin
+
+::::{tab-set}
+:sync-group: install-tool
+
+:::{tab-item} source
+:selected:
+:sync: source
+
+```bash
+uv pip install -e ".[opentelemetry]"
+```
+
+:::
+
+:::{tab-item} package
+:sync: package
+
+```bash
+uv pip install "nvidia-nat[opentelemetry]"
+```
+
+:::
+
+::::
+
+### Configuration
+
+Update your workflow configuration to use the `weave_otel` exporter type:
+
+```yaml
+general:
+  telemetry:
+    tracing:
+      weave_otel:
+        _type: weave_otel
+        project: "nat-demo"
+        entity: "your-team-name"
+```
+
+| Parameter | Description | Example |
+|-----------|-------------|---------|
+| `project` | The name of your W&B Weave project | `"nat-demo"` |
+| `entity` | Your W&B username or team name | `"your-team-name"` |
+| `endpoint` | The W&B Weave OTel endpoint (optional) | `"https://trace.wandb.ai/otel/v1/traces"` |
+| `api_key` | The W&B API key (optional, falls back to `WANDB_API_KEY` env var) | — |
+
+### Run the Workflow
+
+```bash
+nat run --config_file examples/observability/simple_calculator_observability/configs/config-weave-otel.yml --input "What's the sum of 7 and 8?"
+```
+
 ## Resources
 
 - Learn more about tracing [here](https://weave-docs.wandb.ai/guides/tracking/tracing).
 - Learn more about how to navigate the logged traces [here](https://weave-docs.wandb.ai/guides/tracking/trace-tree).
 - Learn more about PII redaction [here](https://weave-docs.wandb.ai/guides/tracking/redact-pii).
+- Learn more about the OTel-based integration [here](https://weave-docs.wandb.ai/guides/tracking/otel).

examples/observability/simple_calculator_observability/README.md

@@ -210,6 +210,22 @@ For simple local development and debugging, you can export traces directly to a
 
 For detailed Weave setup instructions, refer to the [Fine-grained Tracing with Weave](../../../docs/source/run-workflows/observe/observe-workflow-with-weave.md) guide.
 
+### Weave OTel Integration
+
+Weave also supports an [OTel-based integration](https://weave-docs.wandb.ai/guides/tracking/otel) that sends traces via OpenTelemetry. This approach uses the `opentelemetry` plugin instead of the `weave` plugin, which means it does not require installing `weave` as a dependency.
+
+1. Set your Weights & Biases API key:
+
+    ```bash
+    export WANDB_API_KEY=<your_api_key>
+    ```
+
+2. Run the workflow:
+
+    ```bash
+    nat run --config_file examples/observability/simple_calculator_observability/configs/config-weave-otel.yml --input "What's the sum of 7 and 8?"
+    ```
+
 ### AI Safety Monitoring with Patronus
 
 [Patronus](https://patronus.ai/) enables AI safety monitoring and compliance tracking.
@@ -339,6 +355,7 @@ The example includes multiple configuration files for different observability pl
 | `config-langfuse.yml` | Langfuse | Langfuse monitoring and analytics |
 | `config-langsmith.yml` | LangSmith | LangChain/LangGraph ecosystem integration |
 | `config-weave.yml` | Weave | Workflow-focused tracking |
+| `config-weave-otel.yml` | Weave (OTel) | W&B Weave OTel tracing and monitoring integration |
 | `config-patronus.yml` | Patronus | AI safety and compliance monitoring |
 | `config-catalyst.yml` | Catalyst | RagaAI Catalyst integration |
 | `config-galileo.yml` | Galileo | Galileo integration |

examples/observability/simple_calculator_observability/configs/config-weave-otel.yml

@@ -0,0 +1,45 @@
+# SPDX-FileCopyrightText: Copyright (c) 2024-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+general:
+  telemetry:
+    tracing:
+      weave_otel:
+        _type: weave_otel
+        project: "nat-demo"
+        entity: "your-team-name"
+
+function_groups:
+  calculator:
+    _type: calculator
+
+functions:
+  current_datetime:
+    _type: current_datetime
+
+llms:
+  nim_llm:
+    _type: nim
+    model_name: meta/llama-3.1-70b-instruct
+    temperature: 0.0
+    max_tokens: 1024
+
+workflow:
+  _type: react_agent
+  tool_names: [calculator, current_datetime]
+  llm_name: nim_llm
+  verbose: true
+  parse_agent_response_max_retries: 3

packages/nvidia_nat_opentelemetry/src/nat/plugins/opentelemetry/register.py

@@ -15,6 +15,7 @@
 
 import logging
 import os
+from collections.abc import AsyncGenerator
 
 from pydantic import Field
 
@@ -209,6 +210,49 @@ async def galileo_telemetry_exporter(config: GalileoTelemetryExporter, builder:
     )
 
 
+class WeaveOtelTelemetryExporter(BatchConfigMixin, TelemetryExporterBaseConfig, name="weave_otel"):
+    """A telemetry exporter to transmit traces to Weights & Biases Weave via OTel."""
+
+    endpoint: str = Field(
+        description="The W&B Weave OTel endpoint",
+        default="https://trace.wandb.ai/otel/v1/traces",
+    )
+    api_key: SerializableSecretStr = Field(description="The W&B API key",
+                                           default_factory=lambda: SerializableSecretStr(""))
+    project: str = Field(description="The W&B project name.")
+    entity: str = Field(description="The W&B username or team name.")
+
+
+@register_telemetry_exporter(config_type=WeaveOtelTelemetryExporter)
+async def weave_otel_telemetry_exporter(
+    config: WeaveOtelTelemetryExporter, builder: Builder,
+) -> AsyncGenerator["OTLPSpanAdapterExporter", None]:
+    """Create a Weave OTel telemetry exporter."""
+
+    from nat.plugins.opentelemetry import OTLPSpanAdapterExporter
+
+    api_key = get_secret_value(config.api_key) if config.api_key else os.environ.get("WANDB_API_KEY")
+    if not api_key:
+        raise ValueError("API key is required for Weave (set api_key or WANDB_API_KEY env var)")
+
+    headers = {"wandb-api-key": api_key}
+    resource_attributes = {
+        "wandb.project": config.project,
+        "wandb.entity": config.entity,
+    }
+
+    yield OTLPSpanAdapterExporter(
+        endpoint=config.endpoint,
+        headers=headers,
+        resource_attributes=resource_attributes,
+        batch_size=config.batch_size,
+        flush_interval=config.flush_interval,
+        max_queue_size=config.max_queue_size,
+        drop_on_overflow=config.drop_on_overflow,
+        shutdown_timeout=config.shutdown_timeout,
+    )
+
+
 class DBNLTelemetryExporter(BatchConfigMixin, TelemetryExporterBaseConfig, name="dbnl"):
     """A telemetry exporter to transmit traces to DBNL."""