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FakeCallbackHandler Class — langchain Architecture

Architecture documentation for the FakeCallbackHandler class in fake_callback_handler.py from the langchain codebase.

Class python

Entity Profile

Dependency Diagram

graph TD
  6d87458b_f6fb_117c_0495_8d5d853f780e["FakeCallbackHandler"]
  50ee4473_6788_2806_dc06_5fbbc8f64275["BaseCallbackHandler"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|extends| 50ee4473_6788_2806_dc06_5fbbc8f64275
  36d14fc2_cb11_2856_bc3b_120f8e72dda8["BaseFakeCallbackHandlerMixin"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|extends| 36d14fc2_cb11_2856_bc3b_120f8e72dda8
  afcd0a1e_9c9e_7e16_e0ac_5259027d0d05["fake_callback_handler.py"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|defined in| afcd0a1e_9c9e_7e16_e0ac_5259027d0d05
  89f08084_3329_ba81_f6ce_82f2e0483124["ignore_llm()"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|method| 89f08084_3329_ba81_f6ce_82f2e0483124
  95cae379_ad03_727d_803c_8219f952571a["ignore_chain()"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|method| 95cae379_ad03_727d_803c_8219f952571a
  e163d14b_2911_11fb_d88d_194563d8cb0b["ignore_agent()"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|method| e163d14b_2911_11fb_d88d_194563d8cb0b
  b3eddd59_58ae_bfa5_0684_cbc96095a390["ignore_retriever()"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|method| b3eddd59_58ae_bfa5_0684_cbc96095a390
  be93a4b1_6105_e5cb_a9bc_2095daaa3fce["on_llm_start()"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|method| be93a4b1_6105_e5cb_a9bc_2095daaa3fce
  ae42cfc1_4520_45a3_9eb4_df0b7b2e13b7["on_llm_new_token()"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|method| ae42cfc1_4520_45a3_9eb4_df0b7b2e13b7
  a3ac2327_f611_177a_873b_7546da8ba288["on_llm_end()"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|method| a3ac2327_f611_177a_873b_7546da8ba288
  1df98f59_72c6_5176_9685_a92942aab26f["on_llm_error()"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|method| 1df98f59_72c6_5176_9685_a92942aab26f
  19bdcff7_6556_e5ad_99e4_acd5489562e2["on_retry()"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|method| 19bdcff7_6556_e5ad_99e4_acd5489562e2
  d20021d7_dd4c_717e_1e1c_3c414f05a3d8["on_chain_start()"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|method| d20021d7_dd4c_717e_1e1c_3c414f05a3d8
  96e35609_9c21_13db_5caf_f13fbef5eed7["on_chain_end()"]
  6d87458b_f6fb_117c_0495_8d5d853f780e -->|method| 96e35609_9c21_13db_5caf_f13fbef5eed7

Relationship Graph

Source Code

libs/langchain/tests/unit_tests/callbacks/fake_callback_handler.py lines 116–276

class FakeCallbackHandler(BaseCallbackHandler, BaseFakeCallbackHandlerMixin):
    """Fake callback handler for testing."""

    @property
    def ignore_llm(self) -> bool:
        """Whether to ignore LLM callbacks."""
        return self.ignore_llm_

    @property
    def ignore_chain(self) -> bool:
        """Whether to ignore chain callbacks."""
        return self.ignore_chain_

    @property
    def ignore_agent(self) -> bool:
        """Whether to ignore agent callbacks."""
        return self.ignore_agent_

    @property
    def ignore_retriever(self) -> bool:
        """Whether to ignore retriever callbacks."""
        return self.ignore_retriever_

    @override
    def on_llm_start(
        self,
        *args: Any,
        **kwargs: Any,
    ) -> Any:
        self.on_llm_start_common()

    @override
    def on_llm_new_token(
        self,
        *args: Any,
        **kwargs: Any,
    ) -> Any:
        self.on_llm_new_token_common()

    @override
    def on_llm_end(
        self,
        *args: Any,
        **kwargs: Any,
    ) -> Any:
        self.on_llm_end_common()

    @override
    def on_llm_error(
        self,
        *args: Any,
        **kwargs: Any,
    ) -> Any:
        self.on_llm_error_common()

    @override
    def on_retry(
        self,
        *args: Any,
        **kwargs: Any,
    ) -> Any:
        self.on_retry_common()

    @override
    def on_chain_start(
        self,
        *args: Any,
        **kwargs: Any,
    ) -> Any:
        self.on_chain_start_common()

    @override
    def on_chain_end(
        self,
        *args: Any,
        **kwargs: Any,
    ) -> Any:
        self.on_chain_end_common()

    @override
    def on_chain_error(

Defined In

Extends

Source

Frequently Asked Questions

What is the FakeCallbackHandler class?
FakeCallbackHandler is a class in the langchain codebase, defined in libs/langchain/tests/unit_tests/callbacks/fake_callback_handler.py.
Where is FakeCallbackHandler defined?
FakeCallbackHandler is defined in libs/langchain/tests/unit_tests/callbacks/fake_callback_handler.py at line 116.
What does FakeCallbackHandler extend?
FakeCallbackHandler extends BaseCallbackHandler, BaseFakeCallbackHandlerMixin.

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