NetLens is a Kotlin Multiplatform, opt-in network inspector for Ktor Client.
It lets you see what your app is actually sending and receiving — on Android and iOS — without leaving your app.

Think Chucker, but for Ktor + KMP.

• ✅ Kotlin Multiplatform (Android + iOS)
• ✅ Ktor Client plugin (Ktor 3.x)
• ✅ SQLDelight persistence
• ✅ Optional Compose Multiplatform UI
• ✅ Opt-in request & response body capture
• ✅ Header + JSON key redaction by default
• ✅ Safe response interception (does not break .body<T>())
• ✅ No Swift / Obj-C code required

NetLens is published as multiple artifacts so you only include what you need:

commonMain.dependencies {
  implementation("io.github.myapplabs.netlens:netlens-core:0.1.0")
  implementation("io.github.myapplabs.netlens:netlens-ktor:0.1.0")
  implementation("io.github.myapplabs.netlens:netlens-db:0.1.0")

  // Optional UI
  implementation("io.github.myapplabs.netlens:netlens-ui:0.1.0")
}

1. Create the repository

Android

val repo = SqlDelightNetLensRepository(
  SqlDriverFactory()
)

iOS

val repo = SqlDelightNetLensRepository(
  SqlDriverFactory()
)

2. Create NetLens and install the Ktor plugin

val netLens = NetLens(
  config = NetLensConfig(
    enabled = BuildConfig.DEBUG   // strongly recommended
  ),
  repo = repo,
  scope = CoroutineScope(SupervisorJob() + Dispatchers.Default)
)

val client = HttpClient {
  install(NetLensPlugin) {
    this.netLens = netLens
  }
}

What gets logged right away

• HTTP method + URL
• Request & response headers(redacted)
• Status code
• Duration
• Network errors

Request and response bodies are captured only when explicitly enabled per request

client.post("https://api.example.com/login") {
  enableNetLensBodyCapture()
  contentType(ContentType.Application.Json)
  setBody("""{"email":"a@b.com","password":"secret"}""")
}

Why opt-in?

• Prevents accidental logging of credentials
• Makes NetLens safe by default
• Encourages intentional debugging

Bodies are still:

• truncated (maxBodyBytes)
• redacted
• allowed only when content type is approved

If you include netlens-ui, you can show an in-app inspector

@Composable
fun NetLensRoot(repo: NetLensRepository) {
  var selectedId by remember { mutableStateOf<String?>(null) }

  if (selectedId == null) {
    NetLensListScreen(repo) { selectedId = it }
  } else {
    NetLensDetailScreen(repo, selectedId!!) {
      selectedId = null
    }
  }
}

Recommended usage:

• Debug builds only
• Behind a developer menu/secret gesture

NetLensConfig(
  enabled = true,
  maxEntries = 500,
  maxBodyBytes = 64_000,
  captureResponseBodyWhenRequestOptedIn = true,
  contentTypeAllowList = setOf(
    "application/json",
    "text/plain"
  )
)

Headers

• Authorization
• Cookie
• Set-Cookie

JSON keys

• password
• token
• refreshToken
• accessToken
• secret
• apiKey

Developers can supply their own redactor through NetLensConfig.redactor to override header or body sanitization logic.

NetLensConfig(
  redactor = object : NetLensRedactor {
    override fun redactHeaders(headers: Map<String, List<String>>): Map<String, List<String>> = headers
    override fun redactBody(contentType: String?, body: String): String = body
  }
)

Android

enabled = BuildConfig.DEBUG

iOS User you own flag or configuration

• Request body capture supports non-streaming bodies only
• Streaming request bodies are intentionally skipped
• JSON redaction is regex-based (structural parsing coming later)

Apache-2.0

• Streaming request body capture (safe tee)
• Structural JSON redaction
• Search & filters in UI
• Export (HAR / JSON)
• WebSocket inspection

Issues and PRs are welcome.
NetLens is designed to be safe, explicit, and developer-friendly — contributions should follow the same philosophy.