Eric Hare b95d309c46 fix(tracing): surface Langfuse setup failures, pin pydantic>=2.13 (Py3.14) (#13341)
* fix(tracing): surface Langfuse setup failures and pin pydantic>=2.13 for Py3.14

Docker v1.9.3 silently dropped Langfuse traces because the Docker image
was bumped to Python 3.14 while the lockfile still resolved pydantic
2.12.x. Langfuse v3 imports `pydantic.v1.BaseModel`, which only gained
Python 3.14 support in pydantic 2.13. On the user's Docker container,
`from langfuse import Langfuse` raised `pydantic.v1.errors.ConfigError`,
the broad `except Exception` in `_setup_langfuse` logged at debug level,
and the tracer initialized with `_ready = False` — no error in default
logs, no traces in Langfuse. PyPI installs worked because users tend to
run Python 3.10-3.13 where pydantic.v1 is still happy.

Two changes:

- Replace `logger.debug` with `logger.warning`/`logger.exception` in
  `_setup_langfuse` so future failures (network, auth, dependency
  conflicts) surface in logs by default instead of vanishing silently.
- Add `pydantic>=2.13.0` to the `langfuse` extra in
  `src/backend/base/pyproject.toml` so the Python 3.14 import path is
  guaranteed to work whenever the extra is installed, regardless of
  what other deps resolve transitively.

Adds regression tests asserting `_setup_langfuse` calls
`logger.warning`/`logger.exception` on the three failure modes
(auth check returning False, auth check raising, post-auth setup
exception).

Fixes #13317

* [autofix.ci] apply automated fixes

* [autofix.ci] apply automated fixes (attempt 2/3)

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
2026-05-26 20:31:44 +00:00
2025-03-20 00:05:55 +00:00
2026-04-23 17:49:53 -07:00
2024-06-04 09:26:13 -03:00
2026-04-13 23:23:37 +00:00
2026-05-12 14:13:46 +00:00

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Langflow is a powerful platform for building and deploying AI-powered agents and workflows. It provides developers with both a visual authoring experience and built-in API and MCP servers that turn every workflow into a tool that can be integrated into applications built on any framework or stack. Langflow comes with batteries included and supports all major LLMs, vector databases and a growing library of AI tools.

Highlight features

  • Visual builder interface to quickly get started and iterate.
  • Source code access lets you customize any component using Python.
  • Interactive playground to immediately test and refine your flows with step-by-step control.
  • Multi-agent orchestration with conversation management and retrieval.
  • Deploy as an API or export as JSON for Python apps.
  • Deploy as an MCP server and turn your flows into tools for MCP clients.
  • Observability with LangSmith, LangFuse and other integrations.
  • Enterprise-ready security and scalability.

🖥️ Langflow Desktop

Langflow Desktop is the easiest way to get started with Langflow. All dependencies are included, so you don't need to manage Python environments or install packages manually. Available for Windows and macOS.

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Quickstart

Requires Python 3.103.13 and uv (recommended package manager).

Install

From a fresh directory, run:

uv pip install langflow -U

The latest Langflow package is installed. For more information, see Install and run the Langflow OSS Python package.

Run

To start Langflow, run:

uv run langflow run

Langflow starts at http://127.0.0.1:7860.

That's it! You're ready to build with Langflow! 🎉

📦 Other install options

Run from source

If you've cloned this repository and want to contribute, run this command from the repository root:

make run_cli

For more information, see DEVELOPMENT.md.

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Start a Langflow container with default settings:

docker run -p 7860:7860 langflowai/langflow:latest

Langflow is available at http://localhost:7860/. For configuration options, see the Docker deployment guide.

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