Header Actions

Header actions control how request and response headers are stored in the log database. The original request/response headers are never mutated — actions only affect logged data.

HeaderAction Types

Keep

Log the header as-is (default behavior).

headerAction = { HeaderAction.Keep }

Mask(mask: String = "***")

Replace the header value with a mask string in logged data.

headerAction = { key ->
    if (key.equals("Authorization", ignoreCase = true))
        HeaderAction.Mask()       // Value becomes "***"
    else
        HeaderAction.Keep
}

// Custom mask
HeaderAction.Mask("REDACTED")    // Value becomes "REDACTED"
HeaderAction.Mask("[hidden]")    // Value becomes "[hidden]"

Skip

Omit the header entirely from logged data.

headerAction = { key ->
    if (key.equals("Cookie", ignoreCase = true))
        HeaderAction.Skip         // Header not logged at all
    else
        HeaderAction.Keep
}

Common Patterns

Mask Authentication Headers

headerAction = { key ->
    when {
        key.equals("Authorization", ignoreCase = true) -> HeaderAction.Mask()
        key.equals("X-Api-Key", ignoreCase = true) -> HeaderAction.Mask()
        key.equals("Cookie", ignoreCase = true) -> HeaderAction.Skip
        key.equals("Set-Cookie", ignoreCase = true) -> HeaderAction.Skip
        else -> HeaderAction.Keep
    }
}

Allowlist Pattern

Only log specific headers:

val allowedHeaders = setOf("content-type", "accept", "cache-control")

headerAction = { key ->
    if (key.lowercase() in allowedHeaders) HeaderAction.Keep
    else HeaderAction.Skip
}