Files
deerflow-factory/deer-flow/docs/plans/2026-04-01-langfuse-tracing.md
DATA 6de0bf9f5b Initial commit: hardened DeerFlow factory
Vendored deer-flow upstream (bytedance/deer-flow) plus prompt-injection
hardening:

- New deerflow.security package: content_delimiter, html_cleaner,
  sanitizer (8 layers — invisible chars, control chars, symbols, NFC,
  PUA, tag chars, horizontal whitespace collapse with newline/tab
  preservation, length cap)
- New deerflow.community.searx package: web_search, web_fetch,
  image_search backed by a private SearX instance, every external
  string sanitized and wrapped in <<<EXTERNAL_UNTRUSTED_CONTENT>>>
  delimiters
- All native community web providers (ddg_search, tavily, exa,
  firecrawl, jina_ai, infoquest, image_search) replaced with hard-fail
  stubs that raise NativeWebToolDisabledError at import time, so a
  misconfigured tool.use path fails loud rather than silently falling
  back to unsanitized output
- Native client back-doors (jina_client.py, infoquest_client.py)
  stubbed too
- Native-tool tests quarantined under tests/_disabled_native/
  (collect_ignore_glob via local conftest.py)
- Sanitizer Layer 7 fix: only collapse horizontal whitespace, preserve
  newlines and tabs so list/table structure survives
- Hardened runtime config.yaml references only the searx-backed tools
- Factory overlay (backend/) kept in sync with deer-flow tree as a
  reference / source

See HARDENING.md for the full audit trail and verification steps.
2026-04-12 14:23:57 +02:00

3.5 KiB

Langfuse Tracing Implementation Plan

Goal: Add optional Langfuse observability support to DeerFlow while preserving existing LangSmith tracing and allowing both providers to be enabled at the same time.

Architecture: Extend tracing configuration from a single LangSmith-only shape to a multi-provider config, add a tracing callback factory that builds zero, one, or two callbacks based on environment variables, and update model creation to attach those callbacks. If a provider is explicitly enabled but misconfigured or fails to initialize, tracing initialization during model creation should fail with a clear error naming that provider.

Tech Stack: Python 3.12, Pydantic, LangChain callbacks, LangSmith, Langfuse, pytest


Task 1: Add failing tracing config tests

Files:

  • Modify: backend/tests/test_tracing_config.py

Step 1: Write the failing tests

Add tests covering:

  • Langfuse-only config parsing
  • dual-provider parsing
  • explicit enable with missing required Langfuse fields
  • provider enable detection without relying on LangSmith-only helpers

Step 2: Run tests to verify they fail

Run: cd backend && uv run pytest tests/test_tracing_config.py -q Expected: FAIL because tracing config only supports LangSmith today.

Step 3: Write minimal implementation

Update tracing config code to represent multiple providers and expose helper functions needed by the tests.

Step 4: Run tests to verify they pass

Run: cd backend && uv run pytest tests/test_tracing_config.py -q Expected: PASS

Task 2: Add failing callback factory and model attachment tests

Files:

  • Modify: backend/tests/test_model_factory.py
  • Create: backend/tests/test_tracing_factory.py

Step 1: Write the failing tests

Add tests covering:

  • LangSmith callback creation
  • Langfuse callback creation
  • dual callback creation
  • startup failure when an explicitly enabled provider cannot initialize
  • model factory appends all tracing callbacks to model callbacks

Step 2: Run tests to verify they fail

Run: cd backend && uv run pytest tests/test_model_factory.py tests/test_tracing_factory.py -q Expected: FAIL because there is no provider factory and model creation only attaches LangSmith.

Step 3: Write minimal implementation

Create tracing callback factory module and update model factory to use it.

Step 4: Run tests to verify they pass

Run: cd backend && uv run pytest tests/test_model_factory.py tests/test_tracing_factory.py -q Expected: PASS

Task 3: Wire dependency and docs

Files:

  • Modify: backend/packages/harness/pyproject.toml
  • Modify: README.md
  • Modify: backend/README.md

Step 1: Update dependency

Add langfuse to the harness dependencies.

Step 2: Update docs

Document:

  • Langfuse environment variables
  • dual-provider behavior
  • failure behavior for explicitly enabled providers

Step 3: Run targeted verification

Run: cd backend && uv run pytest tests/test_tracing_config.py tests/test_model_factory.py tests/test_tracing_factory.py -q Expected: PASS

Task 4: Run broader regression checks

Files:

  • No code changes required

Step 1: Run relevant suite

Run: cd backend && uv run pytest tests/test_tracing_config.py tests/test_model_factory.py tests/test_tracing_factory.py -q

Step 2: Run lint if needed

Run: cd backend && uv run ruff check packages/harness/deerflow/config/tracing_config.py packages/harness/deerflow/models/factory.py packages/harness/deerflow/tracing

Step 3: Review diff

Run: git diff -- backend/packages/harness backend/tests README.md backend/README.md