Ktor2Curl

Turns Ktor HTTP requests into runnable curl commands for debugging and logging. Pure Kotlin, works on Android, iOS, and JVM (KMP).

Inspired by Ok2Curl for OkHttp.

Features

• Zero-config install: add the plugin, done
• Mask sensitive headers (tokens, API keys) before they hit your logs
• Exclude noisy headers entirely
• Correct multipart/form-data and file-upload rendering
• Bring your own logger: console, Logcat, remote sink, anything

Requirements

Kotlin 2.3+, Ktor 3.5+, Gradle 7.0+.

Install

dependencies {
    implementation("io.github.kabirnayeem99:ktor2curl:3.0.1")
}

Same snippet for KMP (commonMain) and Android-only projects.

Quick Start

val client = HttpClient(CIO) {
    install(KtorToCurl) {
        logger = CurlLogger.console() // or Log.d(), a file sink, anything
    }
}

client.post("https://api.example.com/users") {
    headers.append(HttpHeaders.Authorization, "Bearer YOUR_TOKEN")
    contentType(ContentType.Application.Json)
    setBody("""{"name":"Alice"}""")
}

curl -H 'Authorization: Bearer YOUR_TOKEN' -H 'Content-Type: application/json' 'https://api.example.com/users' --data-binary '{"name":"Alice"}'

Masking sensitive headers

install(KtorToCurl) {
    logger = CurlLogger.console()
    maskedHeaders = setOf(HttpHeaders.Authorization, "X-API-Key")
    excludedHeaders = setOf(HttpHeaders.UserAgent) // dropped entirely, not just masked
}

curl -H 'Authorization: [masked]' -H 'Content-Type: application/json' 'https://api.example.com/users' --data-binary '{"name":"Alice"}'

Configuration

Property	Type	Default	Purpose
logger	CurlLogger	No-op	Where rendered curl commands go
maskedHeaders	Set<String>	emptySet()	Replace values with [masked]
excludedHeaders	Set<String>	emptySet()	Drop headers entirely
maskedQueryParams	Set<String>	emptySet()	Mask query-param values
maskedJsonKeys	Set<String>	emptySet()	Deep-redact JSON body fields
shell	CurlShell	Posix	Quoting dialect (Posix/PowerShell/Cmd)

Full reference with a runnable example per option (timeouts, retries, truncation, shell dialect, custom logger, multipart, and more): docs/API.md.

Troubleshooting

• Dependency won't resolve: make sure mavenCentral() is in repositories {} and Kotlin is 2.3+.
• Nothing gets logged: confirm logger is set, the plugin is installed before any requests are made, and the request actually completes (failed requests may not reach the send pipeline).
• A header isn't masked: header names match case-insensitively, but check for typos; prefer HttpHeaders.* constants over string literals.
• iOS build fails: Kotlin must be 2.3.0+ (older versions can't consume Ktor 3.5's Darwin klib ABI).

Contributing

See CONTRIBUTING.md.

Support

Ktor docs | Issues | Discussions

License

MIT. See LICENSE.