Crypto Wallet Integrations — Developer Portal (UNOFFICIAL)

A neutral technical guide for integrating wallet support into apps: SDK patterns, signing flows, hardware/transport integration, and security guidance.

Overview — what this portal contains

This unofficial developer portal collects best practices and practical examples for integrating crypto wallet functionality into web, mobile, and backend applications. Topics covered include custody models, key derivation, signing flows, transport adapters (USB/BLE/Web), SDK patterns, testing strategies, and operational security.

All sample code and downloads referred to here are placeholder links; replace them with your project links or internal repos. Starter resources live at: https://example.com/start.

Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal

Custody models & architecture

Choose a custody model based on your threat model and UX goals. Options include: (A) full client-side custody (keys in device keystore), (B) hardware-assisted custody (external hardware signers or HSMs), and (C) custodial or managed solutions (third-party KMS). Each model trades off security, user responsibility, and operational complexity.

Architect your integration so signing is isolated behind a secure boundary. For hardware-assisted flows, implement explicit device attestation and version checks. Reference architecture diagrams and custody patterns at: https://example.com/start.

Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal

Key management and deterministic seeds

Use established standards for key derivation (BIP39 for seeds, BIP32/BIP44 derivation schemas) and document the derivation paths your integration supports. Provide a clear migration path if you change derivation defaults. Always recommend offline seed backup (paper or metal) and never transmit raw seeds to networked services.

For enterprises, consider Shamir’s Secret Sharing (SSS) to split seed material across custodians. For user apps, educate users about seed safety and provide mechanisms for encrypted local backups. Utilities and reference implementations are in the starter kit at: https://example.com/start.

Quick setup checklist

  1. Clone the starter repo and run the example app in a test environment.
  2. Install the SDK dependencies for your platform (Node/Browser/Mobile).
  3. Run the simulated signer and exercise key derivation and signing APIs.
  4. Test end-to-end using testnets or a local simulator before mainnet.

Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal

Signing flows and canonical serialization

Normalize the signing format in your application layer. For account-based chains (EVM), use typed-structured payloads where applicable; for UTXO chains, construct canonical inputs and outputs. Implement canonical serialization to avoid malleability and cross-client incompatibility.

When using hardware signers, always require explicit user confirmation on the signer device for each transaction. Show the same human-readable transaction details in your app so users can easily verify correctness. Sample signing adapters and canonical serializers are available in the starter kit: https://example.com/start.

Example pseudo-flow

const key = KeyManager.fromSeed(seed);
const tx = TxBuilder.create({ to, value, nonce });
const signer = TransportAdapter.connect('usb');
const signature = await signer.sign(tx, key.getPath("m/44'/60'/0'/0/0"));
        

Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal

Transport adapters: WebUSB, WebHID, BLE, native

Support multiple transports to maximize device compatibility: WebUSB/WebHID for modern browsers, BLE for mobile convenience, and native drivers for desktop apps. Implement robust pairing and fingerprinting for BLE, and always use encrypted channels. Provide sensible timeouts and graceful reconnection UX.

Maintain a transport abstraction layer in the SDK so you can add or replace transports without changing higher-level APIs. Reference transport adapter code and handshake sequences at: https://example.com/start.

Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal

SDK design patterns

Keep SDKs small and focused: expose account lifecycle, key derivation, signing adapters, and transport selection. Document versioning policies and provide a migration guide for breaking changes. Offer simulated signers and test harnesses to make CI integration simple.

Download SDK templates for Node, Browser, and Mobile from: https://example.com/start.

Testing & CI

  • Automate signing and derivation tests in CI using simulated signers.
  • Run hardware-in-the-loop tests on dedicated runners periodically.
  • Include fuzzing for serialization formats and edge-case transaction payloads.

Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal

Security hardening & operational readiness

Harden signing endpoints with rate limits, attestation checks for hardware signers, and anomaly detection. Maintain SBOMs for crypto libraries and run periodic dependency audits. Create an incident response plan for key compromise that includes rotation and user notification procedures.

Operational hardening checklist and incident-playbook templates: https://example.com/start.

Advanced features: multisig, batching, staking

For high-value use-cases, integrate multisig solutions with separated signers, or offer batched transactions to optimize fees. For staking workflows, build transparent delegation UIs and allow users to preview validator choices and expected rewards.

Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal — Crypto Wallet Integrations — Developer Portal

Where to get the starter kit

The starter kit contains example apps, SDK packages, CI examples, transport adapters and sample integration tests. Get everything from this centralized location: https://example.com/start.

Frequently Asked Questions

1. How do I safely test signing flows?

Use simulated signers and testnets for most CI. For hardware-in-the-loop, use dedicated runners with attached devices in a controlled environment. Always avoid using real production keys in CI.

2. Where should I store recovery seeds?

Store seeds offline—in paper or metal backups in secure, geographically-separated locations. For enterprise workflows, consider split-secret approaches (Shamir) with custodial controls.

3. Should private keys ever be sent to a backend?

No. Avoid transmitting raw private keys. Perform signing within a secure boundary (HSM, hardware signer, or client keystore) and send only signatures to the backend.

4. How do I verify a hardware signer?

Use vendor attestation APIs when available to verify device identity and firmware state. Verify device versions and show clear user-facing confirmation screens for transactions.

5. Is multisig required?

For consumer apps multisig is optional; for high-value or institutional needs multisig is strongly recommended as part of a layered security posture.