OTPless Android Headless SDK Variants

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Overview

OTPless provides three Android SDK variants, all designed to support headless authentication (i.e., OTPless does not require showing a dedicated UI screen). The key difference between the variants is where the authentication orchestration happens:

• Variant 1: Headless via OTPless Web SDK running inside a hidden WebView
• Variant 2: Headless via fully native orchestration (no WebView)
• Variant 3: Headless via native orchestration + reduced footprint (Phone Auth only)

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1) OTPless Android SDK: io.github.otpless-tech:otpless-android-sdk (WebView-backed via OTPless Web SDK) — Deprecated

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What it is

This is our first-generation headless SDK. It keeps the experience headless by using a hidden WebView that loads the OTPless Web SDK in the background. The Android SDK acts as a bridge between the host app and the web layer.

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How it works (high level)

• SDK initializes a hidden WebView (not user-facing)
• WebView loads the OTPless Web SDK in the background
• The web layer communicates with Android via bridge callbacks
• Android SDK forwards structured responses to the host app

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Why it’s still “headless”

• The WebView is not shown as a UI screen
• Authentication orchestration runs in the background
• The host app controls the visible UI while receiving callbacks/events

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Key characteristics

• ✅ Headless experience (background WebView)
• ⚠️ Depends on WebView + Web SDK runtime
• Orchestration happens primarily in the Web SDK, bridged to native

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2) OTPless Headless SDK (Native): io.github.otpless-tech:otpless-headless-sdk (Fully Native, No WebView)

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What it is

This variant removes the WebView dependency completely. The SDK connects directly to OTPless APIs, and orchestration happens in native Android code.

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How it works (high level)

• SDK communicates directly with OTPless APIs
• Orchestration, state management, retries, and callbacks are handled natively
• The host app receives structured auth results and manages its own UI

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Best for

• Apps that prefer fully native execution
• Better control over UX and flow states
• Environments where WebView is discouraged or restricted

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Key characteristics

• ✅ Headless experience
• ✅ No WebView dependency
• ✅ Native orchestration and tighter app integration

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3) OTPless Headless Lite SDK: io.github.otpless-tech:otpless-headless-lite (Native + Size Optimized, Phone Auth Only)

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What it is

A trimmed-down version of Variant 2 focused on minimizing SDK size. It supports only Phone Authentication:

• SNA (Silent Network Authentication)
• OTP

It excludes additional authentication methods such as:

• Google / Truecaller / Facebook flows
• Passkeys
• Other non-phone auth methods

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Best for

• Apps where APK size / dependency footprint is a priority
• Teams that only need phone-number login

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Key characteristics

• ✅ Headless experience
• ✅ No WebView dependency
• ✅ Smallest footprint
• ✅ Phone auth only (SNA/OTP)

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Quick Comparison

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Recommendation

• The WebView-based headless SDK (Variant 1) is deprecated. For new integrations, use the Native Headless SDK (Variant 2).
• If your requirement is only Phone Authentication (SNA/OTP) and SDK size is a key concern, use Headless Lite (Variant 3).