> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt
> Use this file to discover all available pages before exploring further.

# Introducing Tracer

> New Tracer documentation for real-time transaction validation under 100ms, with guides, rules engine, spending limits, and audit and compliance content.

<Badge stroke icon="calendar-days" iconType="regular">January 30, 2026</Badge> <Badge stroke icon="file-code" iconType="regular">Documentation update</Badge> <Badge color="purple" size="lg" stroke icon="eye" iconType="regular">Review recommended</Badge>

## Affects

***

Teams evaluating or integrating real-time transaction validation and spending controls.

This update applies to the public documentation portal. It does not change the runtime API behavior unless the linked product documentation says otherwise.

## What changed

***

We're excited to announce **Tracer** — Lerian's real-time transaction validation and spending control platform. Tracer enables financial institutions to make instant decisions (ALLOW/DENY/REVIEW) for any transaction type in under 100ms, while maintaining regulatory compliance.

### What is Tracer?

***

Tracer is a **transaction validation engine** optimized for low-latency decisions. It validates pre-enriched payloads against configurable rules and spending limits, returning decisions typically in under 35ms.

### Key capabilities

* **Real-time validation** — Response times under 80ms (p99)
* **Rule-based decisions** — Expression-based rules using CEL (Common Expression Language)
* **Spending limits** — Dynamic limits per transaction, account, portfolio, or segment
* **Complete audit trail** — Immutable records with 7+ year retention for SOX/GLBA compliance
* **Product-agnostic** — Supports Card, Wire, PIX, and Crypto transactions

### Documentation

***

This release includes comprehensive documentation to help you get started:

### Guides

* [**What is Tracer**](/en/tracer/what-is-tracer) — Overview of Tracer's capabilities, scope, and design principles
* [**Getting Started**](/en/tracer/getting-started) — Quickstart guide to set up and run your first validation
* [**Integration Guide**](/en/tracer/integration-guide) — How to integrate your authorization system with Tracer
* [**Rules Engine**](/en/tracer/rule-engine) — Create and manage expression-based validation rules
* [**Spending Limits**](/en/tracer/spending-limits) — Configure and monitor spending limits
* [**Audit and Compliance**](/en/tracer/audit-compliance) — Query validation history and audit trail

### API Reference

* [**Validate Transaction**](/en/reference/tracer/validate-transaction) — Submit transactions for validation
* [**Rules API**](/en/reference/tracer/create-rule) — Create, update, and manage rules
* [**Limits API**](/en/reference/tracer/create-limit) — Configure spending limits
* [**Audit Events API**](/en/reference/tracer/list-audit-events) — Query audit trail
* [**Error Reference**](/en/reference/tracer/tracer-error-list) — Complete list of error codes

### Getting started

***

Ready to start validating transactions? Head to the [Getting Started guide](/en/tracer/getting-started) to set up your environment and run your first validation.

For questions about scope and design decisions, check out the [What is Tracer](/en/tracer/what-is-tracer) page, which explains what Tracer focuses on and what it intentionally does not include.

## Impact

***

This is a documentation update. Existing integrations do not need a migration from this release note alone.

## What you need to do

***

<Steps>
  <Step>
    Review the Tracer overview and getting started guides.
  </Step>

  <Step>
    Use the API reference when planning transaction validation, rules, limits, and audit integrations.
  </Step>
</Steps>

### Deadline

None.

### Why

This release introduced Tracer as a documented product area and gave teams a complete starting point for evaluation and integration.