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trulens.apps.langchain.tru_chain

trulens.apps.langchain.tru_chain

LangChain app instrumentation.

Classes

LangChainInstrument

Bases: Instrument

Instrumentation for LangChain apps.

Attributes
INSTRUMENT class-attribute instance-attribute
INSTRUMENT = '__tru_instrumented'

Attribute name to be used to flag instrumented objects/methods/others.

APPS class-attribute instance-attribute
APPS = '__tru_apps'

Attribute name for storing apps that expect to be notified of calls.

Classes
Default

Instrumentation specification for LangChain apps.

Attributes
MODULES class-attribute instance-attribute
MODULES = {'langchain'}

Filter for module name prefix for modules to be instrumented.

CLASSES class-attribute instance-attribute
CLASSES = lambda: {
    RunnableSerializable,
    Serializable,
    Document,
    Chain,
    BaseRetriever,
    BaseLLM,
    BasePromptTemplate,
    BaseMemory,
    BaseChatMemory,
    BaseChatMessageHistory,
    BaseSingleActionAgent,
    BaseMultiActionAgent,
    BaseLanguageModel,
    BaseTool,
    WithFeedbackFilterDocuments,
}

Filter for classes to be instrumented.

METHODS class-attribute instance-attribute
METHODS: Dict[str, ClassFilter] = dict_set_with_multikey(
    {},
    {
        (
            "invoke",
            "ainvoke",
            "stream",
            "astream",
        ): Runnable,
        ("save_context", "clear"): BaseMemory,
        (
            "run",
            "arun",
            "_call",
            "__call__",
            "_acall",
            "acall",
        ): Chain,
        (
            "_get_relevant_documents",
            "get_relevant_documents",
            "aget_relevant_documents",
            "_aget_relevant_documents",
        ): RunnableSerializable,
        ("plan", "aplan"): (
            BaseSingleActionAgent,
            BaseMultiActionAgent,
        ),
        ("_arun", "_run"): BaseTool,
    },
)

Methods to be instrumented.

Key is method name and value is filter for objects that need those methods instrumented

Functions
print_instrumentation
print_instrumentation() -> None

Print out description of the modules, classes, methods this class will instrument.

to_instrument_object
to_instrument_object(obj: object) -> bool

Determine whether the given object should be instrumented.

to_instrument_class
to_instrument_class(cls: type) -> bool

Determine whether the given class should be instrumented.

to_instrument_module
to_instrument_module(module_name: str) -> bool

Determine whether a module with the given (full) name should be instrumented.

tracked_method_wrapper
tracked_method_wrapper(
    query: Lens,
    func: Callable,
    method_name: str,
    cls: type,
    obj: object,
)

Wrap a method to capture its inputs/outputs/errors.

instrument_method
instrument_method(method_name: str, obj: Any, query: Lens)

Instrument a method.

instrument_class
instrument_class(cls)

Instrument the given class cls's new method.

This is done so we can be aware when new instances are created and is needed for wrapped methods that dynamically create instances of classes we wish to instrument. As they will not be visible at the time we wrap the app, we need to pay attention to new to make a note of them when they are created and the creator's path. This path will be used to place these new instances in the app json structure.

instrument_object
instrument_object(
    obj, query: Lens, done: Optional[Set[int]] = None
)

Instrument the given object obj and its components.

TruChain

Bases: App

Recorder for LangChain applications.

This recorder is designed for LangChain apps, providing a way to instrument, log, and evaluate their behavior.

Example: "Creating a LangChain RAG application"

Consider an example LangChain RAG application. For the complete code
example, see [LangChain
Quickstart](https://www.trulens.org/getting_started/quickstarts/langchain_quickstart/).

```python
from langchain import hub
from langchain.chat_models import ChatOpenAI
from langchain.schema import StrOutputParser
from langchain_core.runnables import RunnablePassthrough

retriever = vectorstore.as_retriever()

prompt = hub.pull("rlm/rag-prompt")
llm = ChatOpenAI(model_name="gpt-3.5-turbo", temperature=0)

rag_chain = (
    {"context": retriever | format_docs, "question": RunnablePassthrough()}
    | prompt
    | llm
    | StrOutputParser()
)
```

Feedback functions can utilize the specific context produced by the application's retriever. This is achieved using the select_context method, which then can be used by a feedback selector, such as on(context).

Example: "Defining a feedback function"

```python
from trulens.providers.openai import OpenAI
from trulens.core import Feedback
import numpy as np

# Select context to be used in feedback.
from trulens.apps.langchain import TruChain
context = TruChain.select_context(rag_chain)


# Use feedback
f_context_relevance = (
    Feedback(provider.context_relevance_with_context_reasons)
    .on_input()
    .on(context)  # Refers to context defined from `select_context`
    .aggregate(np.mean)
)
```

The application can be wrapped in a TruChain recorder to provide logging and evaluation upon the application's use.

Example: "Using the TruChain recorder"

```python
from trulens.apps.langchain import TruChain

# Wrap application
tru_recorder = TruChain(
    chain,
    app_name="ChatApplication",
    app_version="chain_v1",
    feedbacks=[f_context_relevance]
)

# Record application runs
with tru_recorder as recording:
    chain("What is langchain?")
```

Further information about LangChain apps can be found on the LangChain Documentation page.

PARAMETER DESCRIPTION
app

A LangChain application.

TYPE: Runnable

**kwargs

Additional arguments to pass to App and AppDefinition.

TYPE: Dict[str, Any] DEFAULT: {}

Attributes
tru_class_info instance-attribute
tru_class_info: Class

Class information of this pydantic object for use in deserialization.

Using this odd key to not pollute attribute names in whatever class we mix this into. Should be the same as CLASS_INFO.

app_id class-attribute instance-attribute
app_id: AppID = Field(frozen=True)

Unique identifier for this app.

Computed deterministically from app_name and app_version. Leaving it here for it to be dumped when serializing. Also making it read-only as it should not be changed after creation.

app_name instance-attribute
app_name: AppName

Name for this app. Default is "default_app".

app_version instance-attribute
app_version: AppVersion

Version tag for this app. Default is "base".

tags instance-attribute
tags: Tags = tags

Tags for the app.

metadata instance-attribute
metadata: Metadata

Metadata for the app.

feedback_definitions class-attribute instance-attribute
feedback_definitions: Sequence[FeedbackDefinitionID] = []

Feedback functions to evaluate on each record.

feedback_mode class-attribute instance-attribute
feedback_mode: FeedbackMode = WITH_APP_THREAD

How to evaluate feedback functions upon producing a record.

record_ingest_mode instance-attribute
record_ingest_mode: RecordIngestMode = record_ingest_mode

Mode of records ingestion.

root_class instance-attribute
root_class: Class

Class of the main instrumented object.

Ideally this would be a ClassVar but since we want to check this without instantiating the subclass of AppDefinition that would define it, we cannot use ClassVar.

initial_app_loader_dump class-attribute instance-attribute
initial_app_loader_dump: Optional[SerialBytes] = None

Serialization of a function that loads an app.

Dump is of the initial app state before any invocations. This can be used to create a new session.

Warning

Experimental work in progress.

app_extra_json instance-attribute
app_extra_json: JSON

Info to store about the app and to display in dashboard.

This can be used even if app itself cannot be serialized. app_extra_json, then, can stand in place for whatever data the user might want to keep track of about the app.

feedbacks class-attribute instance-attribute
feedbacks: List[Feedback] = Field(
    exclude=True, default_factory=list
)

Feedback functions to evaluate on each record.

session class-attribute instance-attribute
session: TruSession = Field(
    default_factory=TruSession, exclude=True
)

Session for this app.

connector property
connector: DBConnector

Database connector.

db property
db: DB

Database used by this app.

instrument class-attribute instance-attribute
instrument: Optional[Instrument] = Field(None, exclude=True)

Instrumentation class.

This is needed for serialization as it tells us which objects we want to be included in the json representation of this app.

recording_contexts class-attribute instance-attribute
recording_contexts: ContextVar[_RecordingContext] = Field(
    None, exclude=True
)

Sequences of records produced by the this class used as a context manager are stored in a RecordingContext.

Using a context var so that context managers can be nested.

instrumented_methods class-attribute instance-attribute
instrumented_methods: Dict[int, Dict[Callable, Lens]] = (
    Field(exclude=True, default_factory=dict)
)

Mapping of instrumented methods (by id(.) of owner object and the function) to their path in this app.

records_with_pending_feedback_results class-attribute instance-attribute
records_with_pending_feedback_results: BlockingSet[
    Record
] = Field(exclude=True, default_factory=BlockingSet)

Records produced by this app which might have yet to finish feedback runs.

manage_pending_feedback_results_thread class-attribute instance-attribute
manage_pending_feedback_results_thread: Optional[Thread] = (
    Field(exclude=True, default=None)
)

Thread for manager of pending feedback results queue.

See _manage_pending_feedback_results.

selector_check_warning class-attribute instance-attribute
selector_check_warning: bool = False

Issue warnings when selectors are not found in the app with a placeholder record.

If False, constructor will raise an error instead.

selector_nocheck class-attribute instance-attribute
selector_nocheck: bool = False

Ignore selector checks entirely.

This may be necessary 1if the expected record content cannot be determined before it is produced.

app instance-attribute
app: Runnable

The langchain app to be instrumented.

root_callable class-attribute
root_callable: FunctionOrMethod = Field(None)

The root callable of the wrapped app.

Functions
on_method_instrumented
on_method_instrumented(
    obj: object, func: Callable, path: Lens
)

Called by instrumentation system for every function requested to be instrumented by this app.

get_method_path
get_method_path(obj: object, func: Callable) -> Lens

Get the path of the instrumented function method relative to this app.

wrap_lazy_values
wrap_lazy_values(
    rets: Any,
    wrap: Callable[[T], T],
    on_done: Callable[[T], T],
    context_vars: Optional[ContextVarsOrValues],
) -> Any

Wrap any lazy values in the return value of a method call to invoke handle_done when the value is ready.

This is used to handle library-specific lazy values that are hidden in containers not visible otherwise. Visible lazy values like iterators, generators, awaitables, and async generators are handled elsewhere.

PARAMETER DESCRIPTION
rets

The return value of the method call.

TYPE: Any

wrap

A callback to be called when the lazy value is ready. Should return the input value or a wrapped version of it.

TYPE: Callable[[T], T]

on_done

Called when the lazy values is done and is no longer lazy. This as opposed to a lazy value that evaluates to another lazy values. Should return the value or wrapper.

TYPE: Callable[[T], T]

context_vars

The contextvars to be captured by the lazy value. If not given, all contexts are captured.

TYPE: Optional[ContextVarsOrValues]

RETURNS DESCRIPTION
Any

The return value with lazy values wrapped.

get_methods_for_func
get_methods_for_func(
    func: Callable,
) -> Iterable[Tuple[int, Callable, Lens]]

Get the methods (rather the inner functions) matching the given func and the path of each.

See WithInstrumentCallbacks.get_methods_for_func.

on_new_record
on_new_record(func) -> Iterable[_RecordingContext]

Called at the start of record creation.

See WithInstrumentCallbacks.on_new_record.

on_add_record
on_add_record(
    ctx: _RecordingContext,
    func: Callable,
    sig: Signature,
    bindings: BoundArguments,
    ret: Any,
    error: Any,
    perf: Perf,
    cost: Cost,
    existing_record: Optional[Record] = None,
    final: bool = False,
) -> Record

Called by instrumented methods if they use _new_record to construct a "record call list.

See WithInstrumentCallbacks.on_add_record.

__rich_repr__
__rich_repr__() -> Result

Requirement for pretty printing using the rich package.

load staticmethod
load(obj, *args, **kwargs)

Deserialize/load this object using the class information in tru_class_info to lookup the actual class that will do the deserialization.

model_validate classmethod
model_validate(*args, **kwargs) -> Any

Deserialized a jsonized version of the app into the instance of the class it was serialized from.

Note

This process uses extra information stored in the jsonized object and handled by WithClassInfo.

continue_session staticmethod
continue_session(
    app_definition_json: JSON, app: Any
) -> AppDefinition

Instantiate the given app with the given state app_definition_json.

Warning

This is an experimental feature with ongoing work.

PARAMETER DESCRIPTION
app_definition_json

The json serialized app.

TYPE: JSON

app

The app to continue the session with.

TYPE: Any

RETURNS DESCRIPTION
AppDefinition

A new AppDefinition instance with the given app and the given app_definition_json state.

new_session staticmethod
new_session(
    app_definition_json: JSON,
    initial_app_loader: Optional[Callable] = None,
) -> AppDefinition

Create an app instance at the start of a session.

Warning

This is an experimental feature with ongoing work.

Create a copy of the json serialized app with the enclosed app being initialized to its initial state before any records are produced (i.e. blank memory).

get_loadable_apps staticmethod
get_loadable_apps()

Gets a list of all of the loadable apps.

Warning

This is an experimental feature with ongoing work.

This is those that have initial_app_loader_dump set.

select_inputs classmethod
select_inputs() -> Lens

Get the path to the main app's call inputs.

select_outputs classmethod
select_outputs() -> Lens

Get the path to the main app's call outputs.

__del__
__del__()

Shut down anything associated with this app that might persist otherwise.

wait_for_feedback_results
wait_for_feedback_results(
    feedback_timeout: Optional[float] = None,
) -> Iterable[Record]

Wait for all feedbacks functions to complete.

PARAMETER DESCRIPTION
feedback_timeout

Timeout in seconds for waiting for feedback results for each feedback function. Note that this is not the total timeout for this entire blocking call.

TYPE: Optional[float] DEFAULT: None

RETURNS DESCRIPTION
Iterable[Record]

An iterable of records that have been waited on. Note a record will be included even if a feedback computation for it failed or timed out.

This applies to all feedbacks on all records produced by this app. This call will block until finished and if new records are produced while this is running, it will include them.

json
json(*args, **kwargs)

Create a json string representation of this app.

awith_ async
awith_(
    func: CallableMaybeAwaitable[A, T], *args, **kwargs
) -> T

Call the given async func with the given *args and **kwargs while recording, producing func results.

The record of the computation is available through other means like the database or dashboard. If you need a record of this execution immediately, you can use awith_record or the App as a context manager instead.

with_ async
with_(func: Callable[[A], T], *args, **kwargs) -> T

Call the given async func with the given *args and **kwargs while recording, producing func results.

The record of the computation is available through other means like the database or dashboard. If you need a record of this execution immediately, you can use awith_record or the App as a context manager instead.

with_record
with_record(
    func: Callable[[A], T],
    *args,
    record_metadata: JSON = None,
    **kwargs
) -> Tuple[T, Record]

Call the given func with the given *args and **kwargs, producing its results as well as a record of the execution.

awith_record async
awith_record(
    func: Callable[[A], Awaitable[T]],
    *args,
    record_metadata: JSON = None,
    **kwargs
) -> Tuple[T, Record]

Call the given func with the given *args and **kwargs, producing its results as well as a record of the execution.

dummy_record
dummy_record(
    cost: Cost = base_schema.Cost(),
    perf: Perf = base_schema.Perf.now(),
    ts: datetime = datetime.datetime.now(),
    main_input: str = "main_input are strings.",
    main_output: str = "main_output are strings.",
    main_error: str = "main_error are strings.",
    meta: Dict = {"metakey": "meta are dicts"},
    tags: str = "tags are strings",
) -> Record

Create a dummy record with some of the expected structure without actually invoking the app.

The record is a guess of what an actual record might look like but will be missing information that can only be determined after a call is made.

All args are Record fields except these:

- `record_id` is generated using the default id naming schema.
- `app_id` is taken from this recorder.
- `calls` field is constructed based on instrumented methods.
instrumented
instrumented() -> Iterable[Tuple[Lens, ComponentView]]

Iteration over instrumented components and their categories.

print_instrumented
print_instrumented() -> None

Print the instrumented components and methods.

format_instrumented_methods
format_instrumented_methods() -> str

Build a string containing a listing of instrumented methods.

print_instrumented_methods
print_instrumented_methods() -> None

Print instrumented methods.

print_instrumented_components
print_instrumented_components() -> None

Print instrumented components and their categories.

select_context classmethod
select_context(app: Optional[Chain] = None) -> Lens

Get the path to the context in the query output.

main_input
main_input(
    func: Callable, sig: Signature, bindings: BoundArguments
) -> str

Determine the main input string for the given function func with signature sig if it is to be called with the given bindings bindings.

main_output
main_output(
    func: Callable,
    sig: Signature,
    bindings: BoundArguments,
    ret: Any,
) -> str

Determine the main out string for the given function func with signature sig after it is called with the given bindings and has returned ret.

acall_with_record async
acall_with_record(*args, **kwargs) -> None

DEPRECATED: Run the chain acall method and also return a record metadata object.

call_with_record
call_with_record(*args, **kwargs) -> None

DEPRECATED: Run the chain call method and also return a record metadata object.

__call__
__call__(*args, **kwargs) -> None

DEPRECATED: Wrapped call to self.app._call with instrumentation. If you need to get the record, use call_with_record instead.