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FakeCallbackHandler Class — langchain Architecture

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

Class python

Entity Profile

Dependency Diagram

graph TD
  4b8e5bd6_69e8_42aa_044f_63f638ae480d["FakeCallbackHandler"]
  af283d05_75a6_5813_267b_f03a32501460["BaseCallbackHandler"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|extends| af283d05_75a6_5813_267b_f03a32501460
  bd0f558e_4f69_e5aa_d113_623bbeb51c3d["BaseFakeCallbackHandlerMixin"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|extends| bd0f558e_4f69_e5aa_d113_623bbeb51c3d
  30343711_5521_a7f5_4f30_8070ee088ac6["_utils.py"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|defined in| 30343711_5521_a7f5_4f30_8070ee088ac6
  3d2bc9a9_638b_7bb2_1b92_2b0f59296967["ignore_llm()"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|method| 3d2bc9a9_638b_7bb2_1b92_2b0f59296967
  95f6501f_e204_f392_b8c6_6dca47472e30["ignore_chain()"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|method| 95f6501f_e204_f392_b8c6_6dca47472e30
  5bc0523c_f464_dbc7_dad9_b9b61930a263["ignore_agent()"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|method| 5bc0523c_f464_dbc7_dad9_b9b61930a263
  b811bd5b_560d_73d4_4099_9959620348d3["ignore_retriever()"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|method| b811bd5b_560d_73d4_4099_9959620348d3
  9763f9a3_6126_17e8_8767_34ad899e959b["on_llm_start()"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|method| 9763f9a3_6126_17e8_8767_34ad899e959b
  526e392e_194d_0718_8eb3_fd792fafe4ac["on_llm_new_token()"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|method| 526e392e_194d_0718_8eb3_fd792fafe4ac
  4d0f9412_e8d1_76de_9d8e_9459cc107f22["on_llm_end()"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|method| 4d0f9412_e8d1_76de_9d8e_9459cc107f22
  6bf73a94_cedd_6c35_0750_f12e1800c291["on_llm_error()"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|method| 6bf73a94_cedd_6c35_0750_f12e1800c291
  d1c38150_6f05_7556_e891_16c5f0494d83["on_retry()"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|method| d1c38150_6f05_7556_e891_16c5f0494d83
  71bc8957_e840_cefe_5388_62adfe19e899["on_chain_start()"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|method| 71bc8957_e840_cefe_5388_62adfe19e899
  f12d5258_97a1_20d5_b790_a5f163f8ad84["on_chain_end()"]
  4b8e5bd6_69e8_42aa_044f_63f638ae480d -->|method| f12d5258_97a1_20d5_b790_a5f163f8ad84

Relationship Graph

Source Code

libs/partners/anthropic/tests/unit_tests/_utils.py lines 114–258

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_

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

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

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

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

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

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

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

    def on_chain_error(
        self,
        *args: Any,
        **kwargs: Any,
    ) -> Any:
        self.on_chain_error_common()

    def on_tool_start(
        self,

Defined In

Extends

Source

Frequently Asked Questions

What is the FakeCallbackHandler class?
FakeCallbackHandler is a class in the langchain codebase, defined in libs/partners/anthropic/tests/unit_tests/_utils.py.
Where is FakeCallbackHandler defined?
FakeCallbackHandler is defined in libs/partners/anthropic/tests/unit_tests/_utils.py at line 114.
What does FakeCallbackHandler extend?
FakeCallbackHandler extends BaseCallbackHandler, BaseFakeCallbackHandlerMixin.

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