ILangfuseClient

NexusLabs.Foundry.Langfuse

ILangfuseClient Interface

Provides the complete non-owning Langfuse client surface for scenarios, experiments, datasets, score configuration, metrics, model pricing, prompts, comments, and known-trace scoring.

public interface ILangfuseClient

Derived
↳ ILangfuseSession

Remarks

Resolve this interface from dependency injection after calling AddFoundryLangfuse(this IServiceCollection, Action<LangfuseOptions>). The facade does not own the host's OpenTelemetry providers or HTTP transport and does not implement System.IDisposable.

For standalone applications that must own and explicitly shut down their OpenTelemetry providers, use Start(LangfuseOptions) and retain the returned ILangfuseSession.

Properties

ILangfuseClient.Datasets Property

Gets the client for reading, creating, and populating Langfuse datasets.

NexusLabs.Foundry.Langfuse.ILangfuseDatasetClient Datasets { get; }

Property Value

ILangfuseDatasetClient

ILangfuseClient.IsEnabled Property

Gets a value indicating whether Langfuse export and API operations are enabled. false indicates a coherent no-op client.

bool IsEnabled { get; }

Property Value

System.Boolean

ILangfuseClient.Metrics Property

Gets the client for reading aggregates from the Langfuse Metrics API.

NexusLabs.Foundry.Langfuse.ILangfuseMetricsClient Metrics { get; }

Property Value

ILangfuseMetricsClient

ILangfuseClient.Models Property

Gets the client for registering Langfuse model price definitions.

NexusLabs.Foundry.Langfuse.ILangfuseModelClient Models { get; }

Property Value

ILangfuseModelClient

ILangfuseClient.Prompts Property

Gets the client for fetching and creating prompts in Langfuse prompt management.

NexusLabs.Foundry.Langfuse.ILangfusePromptClient Prompts { get; }

Property Value

ILangfusePromptClient

ILangfuseClient.PublicationHealth Property

Gets structured trace, REST publication, retry, and local-drain health.

NexusLabs.Foundry.Langfuse.LangfusePublicationHealth PublicationHealth { get; }

Property Value

LangfusePublicationHealth

ILangfuseClient.ScoreConfigs Property

Gets the client for idempotently registering Langfuse score configurations.

NexusLabs.Foundry.Langfuse.ILangfuseScoreConfigClient ScoreConfigs { get; }

Property Value

ILangfuseScoreConfigClient

ILangfuseClient.Scores Property

Gets the client for recording scores against known trace, observation, and session ids.

NexusLabs.Foundry.Langfuse.ILangfuseScoreClient Scores { get; }

Property Value

ILangfuseScoreClient

Methods

ILangfuseClient.AddTraceCommentAsync(string, string, CancellationToken) Method

Attaches a comment to an existing Langfuse trace.

System.Threading.Tasks.Task AddTraceCommentAsync(string traceId, string content, System.Threading.CancellationToken cancellationToken=default(System.Threading.CancellationToken));

Parameters

traceId System.String

The id of an existing Langfuse trace.

content System.String

The comment content.

cancellationToken System.Threading.CancellationToken

A cancellation token.

Returns

System.Threading.Tasks.Task
A task that completes when Langfuse accepts the comment or a non-fatal failure is reported.

ILangfuseClient.BeginExperimentRun(string, string) Method

Begins a Langfuse experiment run whose item traces are linked to an existing dataset.

NexusLabs.Foundry.Langfuse.ILangfuseExperimentRun BeginExperimentRun(string datasetName, string runName);

Parameters

datasetName System.String

The existing dataset to score against.

runName System.String

A caller-supplied run name used for experiment comparison.

Returns

ILangfuseExperimentRun
An ILangfuseExperimentRun. A disabled client returns an inert no-op run.

Exceptions

System.ArgumentException
datasetName or runName is null or whitespace.

ILangfuseClient.BeginExperimentRun(string, string, LangfuseExperimentRunOptions) Method

Begins a Langfuse experiment run whose item traces are linked to an existing dataset.

NexusLabs.Foundry.Langfuse.ILangfuseExperimentRun BeginExperimentRun(string datasetName, string runName, NexusLabs.Foundry.Langfuse.LangfuseExperimentRunOptions? options);

Parameters

datasetName System.String

The existing dataset to score against.

runName System.String

A caller-supplied run name used for experiment comparison.

options LangfuseExperimentRunOptions

Optional description and structured metadata for the run.

Returns

ILangfuseExperimentRun
An ILangfuseExperimentRun. A disabled client returns an inert no-op run.

Exceptions

System.ArgumentException
datasetName or runName is null or whitespace.

ILangfuseClient.BeginScenario(string, string, string, IEnumerable<string>, IReadOnlyDictionary<string,string>) Method

Begins a Langfuse trace scoped to a single evaluation scenario or agent run.

NexusLabs.Foundry.Langfuse.ILangfuseScenario BeginScenario(string name, string? sessionId=null, string? userId=null, System.Collections.Generic.IEnumerable<string>? tags=null, System.Collections.Generic.IReadOnlyDictionary<string,string>? metadata=null);

Parameters

name System.String

The trace name shown in Langfuse.

sessionId System.String

An optional Langfuse session id used to group related traces.

userId System.String

An optional end-user identifier associated with the trace.

tags System.Collections.Generic.IEnumerable<System.String>

Optional tags used to categorize the trace.

metadata System.Collections.Generic.IReadOnlyDictionary<System.String,System.String>

Optional filterable key/value metadata attached to the trace.

Returns

ILangfuseScenario
An ILangfuseScenario to dispose when the scenario completes. A disabled client returns an inert no-op scenario.

Exceptions

System.ArgumentException
name is null or whitespace.