# Arcadia Age API (A3)

> Arcadia Age API (A3) provides compliant, frictionless age assurance built for the US market — without verification walls, identity friction, or storing a single byte of PII. Keep your users flowing. Stay compliant. Currently available in the United States only; EU/EEA/UK country codes are rejected (403 Forbidden).

> For comprehensive documentation including full API reference, request/response schemas, evidence tags, and code examples, see [llms-full.txt](https://www.a3api.io/llms-full.txt).

A3 (Arcadia Age API) is the unified age compliance layer for web, iOS, and Android. California AB 1043 mandates age assurance, but browsers have no Apple or Google age signal — A3 fills that gap. On native apps, A3 normalizes Apple's Declared Age Range API and Google's Play Age Signals into a single response. On the web, A3 provides full age assurance through passive signal fusion. One API call, one response format, one audit trail — regardless of platform. Zero data retention. No verification walls. No stored PII.

## Key Links

- [Documentation](https://www.a3api.io/docs)
- [API Playground](https://www.a3api.io/playground)
- [Pricing](https://www.a3api.io/pricing)
- [Developer Portal (Get API Key)](https://portal.a3api.io)
- [OpenAPI Spec](https://www.a3api.io/openapi.json)
- [AB 1043 Compliance Guide](https://www.a3api.io/docs/compliance/ab-1043)
- [Trust & Reliability](https://www.a3api.io/trust)
- [Privacy Policy](https://www.a3api.io/privacy)
- [Terms of Service](https://www.a3api.io/terms)
- [Browser SDK (`@a3api/signals`)](https://www.a3api.io/docs/integration/sdks#browser-sdk-a3apisignals)
- [Changelog](https://www.a3api.io/changelog)
- [Contact](https://www.a3api.io/contact)

## What A3 Does

A3 provides a REST API endpoint for **age assurance** across web, iOS, and Android. On native apps, it normalizes Apple and Google OS age signals into a single, consistent response. On the web — where no OS signal exists — it provides full age assurance through behavioral biometrics, input complexity, device context, and other passively collected signals. The core use case is California AB 1043 compliance across every platform.

### Core Capabilities

- **Unified Cross-Platform Age Assurance**: One API call (`POST /v1/assurance/assess-age`) works across web, iOS, and Android. On native apps, it normalizes Apple's Declared Age Range API and Google's Play Age Signals into a single response format. On the web, supplementary signals become the primary assessment mechanism — filling the gap where no OS signal exists.
- **Two-Phase Signal Fusion Engine**: Phase 1 treats the OS-provided age bracket as the primary indicator per §1798.501(b)(3)(A). Phase 2 scores five categories of supplementary evidence independently. The OS signal is overridden only when evidence meets the "clear and convincing" legal standard per §1798.501(b)(3)(B). Returns one of four verdicts: `CONSISTENT`, `OVERRIDE`, `REVIEW`, or `PROVISIONAL`. Supports touch-mode (mobile/tablet), pointer-mode (desktop/laptop), and hybrid interaction modes with calibrated thresholds for each.
- **Web-Native Age Assurance**: For browsers where no OS age signal exists, A3's signal fusion engine provides full age assessment through passively collected behavioral and contextual signals — the only path to compliance for web applications serving California users. The `@a3api/signals` npm package is a drop-in browser SDK (<5KB gzipped) that collects these signals automatically and packages them into the exact payload shape expected by the API. Available for vanilla JS, React, and Vue.
- **Audit-Ready Confidence Scoring**: Every response includes a confidence score, age bracket assessment, verdict, evidence tags, and a cryptographic receipt structured for compliance audits.
- **Zero Data Retention**: Fully stateless architecture. No request payloads, images, or personally identifiable information are stored or logged — ever.

## How A3 Handles AB 1043 Compliance

California AB 1043 mandates age assurance for applications, but creates a gap: browsers have no OS age signal. A3 solves compliance across every platform:

1. **Web Compliance**: Browsers have no Apple or Google age signal. A3's signal fusion engine provides full age assurance for web applications using behavioral biometrics, input complexity, and device context — the only path to compliance for web properties serving California users.
2. **Cross-Platform Normalization**: Instead of integrating Apple's Declared Age Range API, Google's Play Age Signals API, and a separate web solution, A3 normalizes all platform signals into a single response format. One API, one response, one audit trail.
3. **Two-Phase Signal Fusion**: On native apps, the OS-provided age bracket is treated as the statutory primary indicator. Five categories of supplementary evidence can override it only when they meet the "clear and convincing" legal standard per §1798.501(b)(3)(B). On the web, supplementary signals become the primary assessment mechanism.
4. **Privacy-by-Design**: The API is stateless and retains zero data. No images, biometric templates, or PII are stored at any point — eliminating data liability.
5. **Audit-Ready Receipts**: Each response includes a verdict, confidence score, evidence tags, and a cryptographic `verification_token` (HMAC-SHA256) — structured for AG investigation defense across every platform.

## Tech Stack

- **Runtime**: AWS Lambda (serverless, auto-scaling)
- **Framework**: NestJS (Node.js / TypeScript)
- **Architecture**: Stateless REST API, zero data retention
- **Validation**: Class-validator DTOs with strict input validation
- **Latency**: Cold starts under 200 ms, warm invocations in single-digit milliseconds
- **Scaling**: Automatic from zero to thousands of concurrent executions
- **Documentation Site**: Next.js (App Router), MDX, deployed as standalone

## Pricing

A3 uses transparent, usage-based pricing. No hidden fees, no minimum commitments. Developers pay only for API calls consumed. See [Pricing](https://www.a3api.io/pricing) for current tiers.

## Getting Started

1. Sign up at the [Developer Portal](https://portal.a3api.io) and create a free API key.
2. Read the [Quick Start Guide](https://www.a3api.io/docs) to make your first API call.
3. Use the [Interactive Playground](https://www.a3api.io/playground) to test endpoints live.
4. Review the [AB 1043 Compliance Guide](https://www.a3api.io/docs/compliance/ab-1043) for integration best practices.

## Frequently Asked Questions

### What is A3 (Arcadia Age API)?
Arcadia Age API (A3) provides compliant, frictionless age assurance built for the US market — without verification walls, identity friction, or storing a single byte of PII. Keep your users flowing. Stay compliant. Built specifically for California AB 1043 with zero data retention and audit-ready confidence scoring.

### How does A3 handle California AB 1043 compliance?
A3 implements a two-phase signal fusion engine. On native apps, the OS-provided age bracket is the primary indicator per §1798.501(b)(3)(A), with supplementary evidence that can override it when meeting the "clear and convincing" standard per §1798.501(b)(3)(B). On the web — where no OS signal exists — supplementary signals become the primary assessment mechanism. A3 normalizes all platforms into one API call, one response format, and one audit trail. The architecture is fully stateless with zero data retention.

### Does A3 store facial images or biometric data?
No. A3 is completely stateless. No images, biometric templates, or personally identifiable information are stored, logged, or persisted. Each request is processed and immediately forgotten.

### What is the latency of the A3 API?
Cold starts are under 200 ms and warm invocations complete in single-digit milliseconds. The API runs on AWS Lambda for automatic scaling.

### What tech stack does A3 use?
A3 is built with NestJS (TypeScript) on AWS Lambda. The documentation site uses Next.js with the App Router. All endpoints use class-validated DTOs with strict input validation.

### How much does A3 cost?
A3 uses transparent, pay-per-use pricing with no hidden fees or minimum commitments. Visit a3api.io/pricing for current rates.

### How do I get started with A3?
Sign up at portal.a3api.io for a free API key, then follow the quick start guide at www.a3api.io/docs.