> ## 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.

# Tracer

> Reference the Tracer fields used in real-time transaction validation — requests, rules, spending limits, and decision responses.

This page covers fields specific to Tracer — Lerian's real-time transaction validation engine. These fields are used across validation requests, rules, spending limits, and decision responses.

## 1. Validation requests

***

| Field                | Description                                                            | Used in |
| -------------------- | ---------------------------------------------------------------------- | ------- |
| requestId            | Client-generated unique ID for idempotency and audit correlation       | Tracer  |
| transactionType      | Type of transaction: CARD, WIRE, Pix, or CRYPTO                        | Tracer  |
| subType              | Transaction subtype for additional context (e.g., debit, credit)       | Tracer  |
| amount               | Transaction amount in cents (smallest currency unit, must be positive) | Tracer  |
| currency             | ISO 4217 currency code (3 uppercase letters)                           | Tracer  |
| transactionTimestamp | When the transaction occurred (RFC 3339 format with timezone)          | Tracer  |

## 2. Validation responses

***

| Field            | Description                                                  | Used in |
| ---------------- | ------------------------------------------------------------ | ------- |
| validationId     | Server-generated unique identifier for the validation record | Tracer  |
| decision         | Validation decision: ALLOW, DENY, or REVIEW                  | Tracer  |
| reason           | Human-readable reason for the decision                       | Tracer  |
| matchedRuleIds   | IDs of rules that matched and triggered the decision         | Tracer  |
| evaluatedRuleIds | IDs of all rules that were evaluated                         | Tracer  |
| processingTimeMs | Processing time in milliseconds                              | Tracer  |
| totalRulesLoaded | Total number of rules loaded for evaluation                  | Tracer  |
| truncated        | Whether the response was truncated due to size limits        | Tracer  |

## 3. Rules

***

| Field         | Description                                                                | Used in |
| ------------- | -------------------------------------------------------------------------- | ------- |
| ruleId        | Unique identifier for the rule                                             | Tracer  |
| name          | Human-readable rule name (globally unique, max 255 characters)             | Tracer  |
| description   | Rule purpose and logic explanation (max 1000 characters)                   | Tracer  |
| expression    | CEL expression that must evaluate to boolean (max 5000 characters)         | Tracer  |
| action        | Action taken when the expression evaluates to true: ALLOW, DENY, or REVIEW | Tracer  |
| scopes        | Array of scopes that determine which transactions this rule applies to     | Tracer  |
| status        | Rule lifecycle status: DRAFT, ACTIVE, INACTIVE, or DELETED                 | Tracer  |
| activatedAt   | When the rule was last activated (null if never activated)                 | Tracer  |
| deactivatedAt | When the rule was last deactivated (null if never deactivated)             | Tracer  |

## 4. Spending limits

***

| Field           | Description                                                                                   | Used in |
| --------------- | --------------------------------------------------------------------------------------------- | ------- |
| limitId         | Unique identifier for the limit                                                               | Tracer  |
| name            | Human-readable limit name (max 255 characters)                                                | Tracer  |
| description     | Limit purpose and usage explanation (max 1000 characters)                                     | Tracer  |
| limitType       | Type of limit: DAILY, WEEKLY, MONTHLY, CUSTOM, or PER\_TRANSACTION (immutable after creation) | Tracer  |
| maxAmount       | Maximum decimal amount as a string, for example `"1000.00"`                                   | Tracer  |
| currency        | ISO 4217 currency code (immutable after creation)                                             | Tracer  |
| scopes          | Array of scopes that determine which transactions this limit applies to                       | Tracer  |
| status          | Limit lifecycle status: DRAFT, ACTIVE, INACTIVE, or DELETED                                   | Tracer  |
| activeTimeStart | Start of the daily active window in `HH:mm` format                                            | Tracer  |
| activeTimeEnd   | End of the daily active window in `HH:mm` format                                              | Tracer  |
| customStartDate | Start date-time for CUSTOM limits                                                             | Tracer  |
| customEndDate   | End date-time for CUSTOM limits                                                               | Tracer  |

## 5. Limit usage

***

| Field           | Description                                                             | Used in |
| --------------- | ----------------------------------------------------------------------- | ------- |
| limitAmount     | Total limit amount in cents                                             | Tracer  |
| currentUsage    | Current or projected usage after applying the transaction               | Tracer  |
| exceeded        | Whether the limit was exceeded during validation                        | Tracer  |
| period          | Limit period type: DAILY, WEEKLY, MONTHLY, CUSTOM, or PER\_TRANSACTION  | Tracer  |
| scope           | Human-readable scope description (e.g., "account:uuid", "segment:uuid") | Tracer  |
| attemptedAmount | Transaction amount being validated, in cents                            | Tracer  |

## 6. Scopes and targeting

***

| Field           | Description                                                | Used in |
| --------------- | ---------------------------------------------------------- | ------- |
| accountId       | Account identifier for scope targeting                     | Tracer  |
| segmentId       | Segment identifier for scope targeting                     | Tracer  |
| portfolioId     | Portfolio identifier for scope targeting                   | Tracer  |
| merchantId      | Merchant identifier for scope targeting                    | Tracer  |
| transactionType | Transaction type filter: CARD, WIRE, Pix, or CRYPTO        | Tracer  |
| category        | Merchant Category Code (4-digit MCC per ISO 18245)         | Tracer  |
| country         | Merchant country (ISO 3166-1 alpha-2, 2 uppercase letters) | Tracer  |