What is a log API? A practical developer’s guide
Understand logging libraries, ingestion endpoints, and query interfaces—and build an event contract that connects them.
BUILT AROUND BETTER SIGNALEvery event.
Every event.
A clearer picture.
Logging patterns for applications, AI, and everything in between. Understand your events, connect the context, and build with less guesswork.
Structured JSONPrivacy-mindedDeveloper-first
{
"schema_version": "1.0",
"timestamp": "2026-09-21T09:41:02.184Z",
"severity": "INFO",
"event_id": "evt_demo_001",
"event_name": "request.completed",
"service": "checkout-api",
"attributes": {
"route": "/orders/{id}",
"status_code": 200,
"duration_ms": 42
}
}Synthetic fixture · nothing is sentDownload JSON ↗
{
"schema_version": "1.0",
"timestamp": "2026-09-21T09:41:02.184Z",
"severity": "INFO",
"event_id": "evt_demo_002",
"event_name": "generation.completed",
"service": "assistant-worker",
"attributes": {
"workflow_id": "wf_demo_042",
"model": "example-model",
"config_version": "prompt-v3",
"outcome": "completed",
"duration_ms": 842
}
}Synthetic fixture · nothing is sentDownload JSON ↗
{
"schema_version": "1.0",
"timestamp": "2026-09-21T09:41:02.184Z",
"severity": "INFO",
"event_id": "evt_demo_003",
"event_name": "usage.recorded",
"service": "assistant-worker",
"attributes": {
"input_tokens": 1240,
"output_tokens": 386,
"usage_source": "sample",
"usage_complete": true
}
}Synthetic fixture · nothing is sentDownload JSON ↗
{
"schema_version": "1.0",
"timestamp": "2026-09-21T09:41:02.184Z",
"severity": "WARN",
"event_id": "evt_demo_005",
"event_name": "access.denied",
"service": "identity-service",
"attributes": {
"actor_ref": "actor_demo_07",
"action": "settings.write",
"decision": "deny",
"outcome": "not_executed"
}
}Synthetic fixture · nothing is sentDownload JSON ↗
One shared envelopeContext across your stack
10 practical guidesPatterns you can build on
From your first event to your next investigation.
JSONHTTPAI & LLMTracesSecurity
YOUR STACK, IN CONTEXT
Different signals. A shared foundation.
Explore the fields, decisions, and implementation patterns behind every kind of log.
AI log API
Design AI logs for workflows, retrieval, tool actions, and application outcomes—with metadata at the center.
Explore the patternToken log API
Track input and output token measurements, preserve their provenance, and keep estimates separate from reported usage.
Explore the patternLLM log API
Connect LLM events to retrieval, retries, validation, and delivery so a single request tells a coherent story.
Explore the patternWeb traffic log API
Understand routes, response outcomes, and latency while keeping edge, proxy, and application observations distinct.
Explore the patternSecurity log API
Build useful security events around access checks, administrative actions, and sensitive changes—not just generic errors.
Explore the patternFirewall log API
Read firewall and WAF events with their original source, rule, action, and request context intact.
Explore the patternA BETTER WAY TO THINK ABOUT LOGS
Good logs start
before ingestion.
01
Define the signal.
Choose stable fields and a clear outcome. Keep sensitive content out of the default event.
02
Make delivery deliberate.
Document validation, queue limits, and what an acknowledgment actually means.
03
Connect the context.
Link related events so the next investigation starts with evidence, not interpretation.
AN EVENT’S JOURNEY ILLUSTRATIVE PATTERN
Application
AI / LLM
Web traffic
Security
A clear event contractStructured · versioned · intentional
CollectProtectInvestigate
Your pipeline. Your storage. One understandable event.
Context, not clutter.
Keep the identifiers and outcomes that answer a real question.
Less sensitive data.
Prefer safe metadata over complete requests and private prompts.
Visible failure paths.
Make missing records, retries, and delivery limits part of the design.
THE LOGAPI FIELD NOTES
Practical answers. Useful starting points.
Token usage logging: measurements, estimates, and cost
Keep reported usage separate from estimates, handle retries, and make cost calculations explainable.
Firewall log analysis: from rule match to investigation
Preserve rule decisions, review false positives, and connect edge events to application evidence.
A LITTLE MORE CLARITY
Good questions.
Clear answers.
A few things worth knowing before your first event.
Browse the documentation →What is a log API?
A log API can mean an application logging interface, an event-ingestion endpoint, or a query interface over stored records. Our guides separate these responsibilities so you can design each boundary deliberately.
How are AI logs different from LLM logs?
AI logging can cover the full application workflow, including retrieval and tool actions. LLM logging focuses on model-related operations, usage, and completion states. Both benefit from shared identifiers and explicit outcomes.
Does token logging record access tokens?
No. The token guides discuss model usage measurements. Authentication tokens, passwords, and other credentials should not be copied into routine telemetry.
Are the events in the explorer live?
No. Every event in the explorer is a fixed synthetic fixture. Switching tabs, copying an event, or downloading JSON does not submit data to a logging endpoint.
Is LogAPI.com a hosted logging service?
This site provides implementation guides, schemas, and local examples. A production collector, access policy, and storage destination belong in your own configured environment.
Where should I start?
Read the quickstart to emit one structured event locally. Then review the event schema and the delivery guide before connecting a production pipeline.
ONE EVENT IS A GOOD START
Make your next log more useful.
Start with a clear schema. Keep the context that matters.