slog Provider¶

The slog provider logs trace events to Go's standard log/slog package. It's useful for local development, debugging, or as a fallback when no observability platform is configured.

Installation¶

The slog provider is included in OmniObserve:

go get github.com/plexusone/omniobserve

Configuration¶

import (
    "log/slog"

    "github.com/plexusone/omniobserve/llmops"
    _ "github.com/plexusone/omniobserve/llmops/slog"
)

// Use default slog logger
provider, err := llmops.Open("slog",
    llmops.WithProjectName("my-project"),
)

// Or use a custom logger
provider, err := llmops.Open("slog",
    llmops.WithLogger(slog.Default()),
    llmops.WithProjectName("my-project"),
)

Features¶

Feature	Supported
Tracing	:white_check_mark:
Evaluation	:x:
Prompts	:x:
Datasets	:x:
Experiments	:x:
Streaming	:x:

Log Output¶

The slog provider logs trace and span events with structured attributes:

INFO trace started trace_id=abc123 name=chat-workflow project=my-project
INFO span started span_id=def456 trace_id=abc123 name=llm-call type=llm model=gpt-4
INFO span ended span_id=def456 trace_id=abc123 name=llm-call duration=1.5s prompt_tokens=10 completion_tokens=8
INFO trace ended trace_id=abc123 name=chat-workflow duration=2.1s

Use Cases¶

Local Development: See traces in your terminal without external services
Debugging: Understand trace flow during development
Fallback: Default provider when no other is configured
Testing: Verify tracing instrumentation in tests

Custom Logger¶

Configure with a JSON logger for structured output:

logger := slog.New(slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{
    Level: slog.LevelDebug,
}))

provider, _ := llmops.Open("slog",
    llmops.WithLogger(logger),
)