The choice between non-custodial and custodial embedded wallet architecture is the most consequential technical decision in an embedded crypto wallet integration, and it affects every downstream design choice including key management, user experience, security architecture, and regulatory exposure. A non-custodial embedded wallet gives the user ultimate control over their private key, with the platform's role limited to facilitating key generation and storage in a way that does not give the platform itself access to the user's funds. Non-custodial approaches using multi-party computation split the private key across multiple parties so that no single party, including the platform, can unilaterally sign transactions. This approach preserves the trustless properties of blockchain ownership but introduces technical complexity in the key management infrastructure.
A custodial embedded wallet gives the platform control over the private keys on the user's behalf, simplifying the user experience at the cost of making the platform responsible for the security and availability of those keys. Custodial embedded wallets are simpler to implement and easier for users to interact with, but they expose the platform to custody liability and create a single point of failure if the platform's key management infrastructure is compromised. 27 Blockchain helps clients assess the right embedded wallet architecture for their specific platform based on the user base, the value of assets the wallet will hold, the regulatory environment the platform operates in, and the security resources the platform can dedicate to key management infrastructure. The embedded wallet solution that results is built to the architecture decision made in that assessment rather than defaulting to whichever approach is simplest to implement.
