org.llm4s.trace

ANSI escape codes for terminal color formatting.

Provides a centralized set of color constants used by console-based tracing implementations for improved readability during development and debugging.

Attributes

Note

These codes work on most Unix terminals and Windows Terminal. They may not render correctly in non-ANSI-compatible environments.

Example

import org.llm4s.trace.AnsiColors._
println(s"${GREEN}Success!${RESET}")
println(s"${RED}${BOLD}Error: Something failed${RESET}")

Supertypes

class Object

trait Matchable

class Any

Self type

AnsiColors.type

Console-based Tracing implementation with colored, formatted output.

Prints trace events to standard output with ANSI color formatting for improved readability during development and debugging. Returns Result[Unit] to support functional composition.

== Features ==

Color-coded output by event type (errors in red, success in green, etc.)
Visual separators and headers for different trace sections
Formatted display of all TraceEvent types
Truncation of long JSON content for readability
Timestamps on all events

== Usage ==

val tracing: Tracing = new ConsoleTracing()

// Trace events functionally
for {
 _ <- tracing.traceEvent(TraceEvent.AgentInitialized("query", Vector("tool1")))
 _ <- tracing.traceTokenUsage(TokenUsage(100, 50, 150), "gpt-4", "completion")
} yield ()

Attributes

See also: NoOpTracing for silent tracing

LangfuseTracing for production observability

AnsiColors for color constants used
Supertypes: trait Tracing

class Object

trait Matchable

class Any

Default implementation of LangfuseBatchSender using HTTP requests.

Sends trace events to Langfuse using basic authentication with the provided public and secret keys. Handles both successful responses (200-299) and partial success responses (207).

Logs warnings if credentials are not configured and errors if the HTTP request fails.

Attributes

Supertypes: trait LangfuseBatchSender

class Object

trait Matchable

class Any

Abstraction for sending trace events to Langfuse in batches.

Implementations handle the HTTP communication with the Langfuse API, including authentication, error handling, and logging.

Attributes

See also: DefaultLangfuseBatchSender for the standard implementation
Supertypes: class Object

trait Matchable

class Any
Known subtypes: class DefaultLangfuseBatchSender

Configuration for calling the Langfuse HTTP API.

Value parameters

langfuseUrl: Base URL of the Langfuse API endpoint
publicKey: Langfuse public key for authentication
secretKey: Langfuse secret key for authentication

Attributes

Supertypes: trait Serializable

trait Product

trait Equals

class Object

trait Matchable

class Any
Show all

Langfuse Tracing implementation for production observability.

Sends trace events to Langfuse for centralized observability, debugging, and LLM application monitoring. Supports all trace event types with type-safe Result[Unit] return values.

== Features ==

Real-time event streaming to Langfuse
Hierarchical trace structure (traces with child spans)
Token usage and cost tracking
Error logging with stack traces
Agent state snapshots with conversation history

== Configuration ==

Configure via environment variables or direct instantiation:

// Environment variables
LANGFUSE_PUBLIC_KEY=pk-lf-...
LANGFUSE_SECRET_KEY=sk-lf-...
LANGFUSE_URL=https://cloud.langfuse.com (optional)

// Or programmatic configuration
val tracing = new LangfuseTracing(
 langfuseUrl = "https://cloud.langfuse.com",
 publicKey = "pk-lf-...",
 secretKey = "sk-lf-...",
 environment = "production",
 release = "1.0.0",
 version = "1.0.0"
)

== Usage ==

val tracing: Tracing = LangfuseTracing.from(config)

for {
 _ <- tracing.traceEvent(TraceEvent.AgentInitialized("query", tools))
 _ <- tracing.traceCompletion(completion, "gpt-4")
 _ <- tracing.traceTokenUsage(usage, "gpt-4", "completion")
} yield ()

Value parameters

environment: Environment name (e.g., "production", "staging")
langfuseUrl: Langfuse API URL (default: https://cloud.langfuse.com)
publicKey: Langfuse public key for authentication
release: Release/version identifier
secretKey: Langfuse secret key for authentication
version: API version

Attributes

See also: ConsoleTracing for local development

NoOpTracing for disabled tracing

TracingMode for configuration modes
Companion: object
Supertypes: trait Tracing

class Object

trait Matchable

class Any

Factory methods for LangfuseTracing.

Attributes

Companion: class
Supertypes: class Object

trait Matchable

class Any
Self type: LangfuseTracing.type

No-operation Tracing implementation that silently discards all events.

All methods return Right(()) immediately without performing any operations. Use this implementation when tracing is disabled or not needed.

== Usage ==

val tracing: Tracing = new NoOpTracing()

// All operations succeed silently
tracing.traceEvent(TraceEvent.CustomEvent("test", ujson.Obj())) // Returns Right(())
tracing.traceError(new Exception("ignored")) // Returns Right(())

== Use Cases ==

Production environments where tracing overhead is undesirable
Unit tests that don't need trace output
Default fallback when no tracing is configured

Attributes

See also: ConsoleTracing for development/debugging

LangfuseTracing for production observability
Supertypes: trait Tracing

class Object

trait Matchable

class Any

Type-safe trace events for better composability and type safety

Attributes

Companion: object
Supertypes: class Object

trait Matchable

class Any
Known subtypes: class AgentInitialized

class AgentStateUpdated

class CompletionReceived

class CostRecorded

class CustomEvent

class EmbeddingUsageRecorded

class ErrorOccurred

class RAGOperationCompleted

class TokenUsageRecorded

class ToolExecuted
Show all

Attributes

Companion: trait
Supertypes: trait Sum

trait Mirror

class Object

trait Matchable

class Any
Self type: TraceEvent.type

Type-safe tracing interface for observability and debugging.

Provides a functional approach to tracing with Result[Unit] return types for proper error handling and composition. Supports multiple backends including console output, Langfuse, and custom implementations.

== Implementations ==

LangfuseTracing - Production observability via Langfuse
ConsoleTracing - Colored console output for development
NoOpTracing - Silent implementation for testing/disabled tracing

== Usage ==

// Create from settings
val tracing = Tracing.create(settings)

// Or use directly
val tracing: Tracing = new ConsoleTracing()

// Trace events functionally
for {
 _ <- tracing.traceEvent(TraceEvent.AgentInitialized("query", tools))
 _ <- tracing.traceTokenUsage(usage, "gpt-4", "completion")
} yield ()

== Composition ==

Tracers can be composed using TracingComposer:

val combined = TracingComposer.combine(consoleTracer, langfuseTracer)
val filtered = TracingComposer.filter(tracer)(_.eventType == "error_occurred")

Attributes

See also: TraceEvent for available event types

TracingComposer for composition utilities
Companion: object
Supertypes: class Object

trait Matchable

class Any
Known subtypes: class ConsoleTracing

class LangfuseTracing

class NoOpTracing

Factory for creating Tracing instances.

Creates the appropriate tracing implementation based on configuration settings.

// From TracingSettings
val tracing = Tracing.create(settings)

// Direct instantiation
val console = new ConsoleTracing()
val noop = new NoOpTracing()

Attributes

See also: TracingMode for available modes
Companion: trait
Supertypes: class Object

trait Matchable

class Any
Self type: Tracing.type

Utilities for composing multiple tracers.

Provides functional composition patterns for combining, filtering, and transforming trace events across multiple tracing backends.

== Combining Tracers ==

Send events to multiple backends simultaneously:

val combined = TracingComposer.combine(consoleTracer, langfuseTracer)
combined.traceEvent(event) // Sends to both

== Filtering Events ==

Only trace events matching a predicate:

val errorsOnly = TracingComposer.filter(tracer)(_.eventType == "error_occurred")

== Transforming Events ==

Modify events before tracing:

val enriched = TracingComposer.transform(tracer) {
 case e: TraceEvent.CustomEvent => e.copy(name = "prefix_" + e.name)
 case other => other
}

Attributes

Companion: object
Supertypes: class Object

trait Matchable

class Any
Known subtypes: object TracingComposer

Attributes

Companion: trait
Supertypes: trait TracingComposer

class Object

trait Matchable

class Any
Self type: TracingComposer.type

Type-safe tracing modes

Attributes

Companion: object
Supertypes: trait Serializable

trait Product

trait Equals

class Object

trait Matchable

class Any
Show all
Known subtypes: object Console

object Langfuse

object NoOp

Attributes

Companion: trait
Supertypes: trait Sum

trait Mirror

class Object

trait Matchable

class Any
Self type: TracingMode.type

org.llm4s.trace

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