[pull] main from langfuse:main

.github/workflows/zizmor.yml

@@ -26,7 +26,7 @@ jobs:
         with:
           persist-credentials: false
       - name: Run zizmor
-        uses: zizmorcore/zizmor-action@3dc1ecc9bcb9e94e9b2c709687979e1298497054 # v0.6.2
+        uses: zizmorcore/zizmor-action@70fb788f84895a7701f5643d103d587e460b5c99 # v0.6.3
         with:
           advanced-security: ${{ github.event_name == 'push' && 'true' || 'false' }}
           min-severity: low

README.md

@@ -9,13 +9,21 @@
 [![Discord](https://img.shields.io/discord/1111061815649124414?style=flat-square&logo=Discord&logoColor=white&label=Discord&color=%23434EE4)](https://discord.gg/7NXusRtqYU)
 [![YC W23](https://img.shields.io/badge/Y%20Combinator-W23-orange?style=flat-square)](https://www.ycombinator.com/companies/langfuse)
 
+> [!IMPORTANT]
+> The SDK was rewritten in v4 and released in March 2026. Refer to the [v4 migration guide](https://langfuse.com/docs/observability/sdk/upgrade-path/python-v3-to-v4) for instructions on updating your code.
+>
+> **This is the latest Langfuse Python SDK (v4, OpenTelemetry).** The legacy v2 client API (`trace()`, `span()`, `generation()`, `api.trace.list`) is **deprecated**. Do **not** use it for new instrumentation.
+>
+> **Latest Python SDK (OpenTelemetry):** `pip install langfuse`. Use `get_client()` + `start_as_current_observation` / `@observe`. Prompts/datasets/scores: the same `langfuse` package. Docs: https://langfuse.com/docs/observability/sdk/overview. Upgrade: [v2 to v3](https://langfuse.com/docs/observability/sdk/upgrade-path/python-v2-to-v3), [v3 to v4](https://langfuse.com/docs/observability/sdk/upgrade-path/python-v3-to-v4).
+>
+> Query traces with [Observations API v2](https://langfuse.com/docs/api-and-data-platform/features/observations-api) (`GET /api/public/v2/observations`, [API reference](https://api.reference.langfuse.com/#tag/observationsv2)), not `GET /api/public/traces` / `api.trace.list`.
+>
+> **Data freshness:** the only real-time path is OpenTelemetry ingestion (this SDK at `langfuse` >= 4.7.0, or any OTel exporter sending `x-langfuse-ingestion-version: 4`) combined with the [Observations API v2](https://langfuse.com/docs/api-and-data-platform/features/observations-api) and [Metrics API v2](https://langfuse.com/docs/metrics/features/metrics-api). All other GET APIs from all SDK versions can be up to 10 minutes behind.
+
 The [Langfuse](https://langfuse.com) Python SDK covers the full platform: **observability/tracing** (OpenTelemetry-based, with OpenAI and LangChain integrations), **datasets & experiments** (offline evaluation and regression testing of prompt/model changes, including [CI via GitHub Actions](https://github.com/langfuse/experiment-action)), **LLM-as-a-judge and custom evaluations/scores**, **prompt management**, and a **full REST API client**.
 
 ## Installation
 
-> [!IMPORTANT]
-> The SDK was rewritten in v4 and released in March 2026. Refer to the [v4 migration guide](https://langfuse.com/docs/observability/sdk/upgrade-path/python-v3-to-v4) for instructions on updating your code.
-
 ```
 pip install langfuse
 ```
@@ -52,3 +60,5 @@ langfuse.flush()
 - Full documentation: https://langfuse.com/docs
 - Machine-readable docs index (for AI agents): https://langfuse.com/llms.txt
 - API reference of this package: https://python.reference.langfuse.com
+- REST API reference (Observations API v2, Metrics API v2, Scores API v3): https://api.reference.langfuse.com
+- Data freshness and real-time ingestion: https://langfuse.com/docs/compatibility#faq-delay

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "langfuse"
-version = "4.15.2"
+version = "4.15.3"
 description = "Langfuse Python SDK - LLM observability/tracing, datasets, experiments, LLM-as-a-judge evaluation, and prompt management"
 readme = "README.md"
 authors = [{ name = "langfuse", email = "developers@langfuse.com" }]