Capsule

Capsule is a wallet-as-a-service platform that gives developers the infrastructure to embed non-custodial crypto wallets directly into their applications. Rather than forcing users to install separate browser extensions or manage seed phrases, Capsule handles key generation, authentication, and cross-chain signing behind a set of SDKs and APIs that developers integrate into web, mobile, and server environments. In January 2025, the company rebranded as Para, though the product, team, and underlying technology are continuous with the original Capsule infrastructure.

The Problem Capsule Solves

Getting users from a sign-up screen to an active on-chain wallet has been one of the recurring friction points in crypto product development. Traditional approaches push the burden onto the user — download a wallet app, write down a seed phrase, copy an address into the dApp — steps that routinely cause abandonment. A second problem affects multi-app ecosystems: each application typically provisions its own isolated wallet, leaving users with fragmented identities and balances spread across incompatible contexts.

Capsule addresses both problems. It provides hosted infrastructure for wallet creation and authentication so developers do not build key management from scratch, and it implements a cross-app portability model so a wallet created inside one application can be used to sign transactions in another, without re-onboarding.

How It Works

The security foundation is 2-of-2 multi-party computation (MPC). When a wallet is created, a private key is never assembled in one place. Instead, key shares are distributed between the user's device — stored in a secure enclave — and Capsule's backend infrastructure. Both shares are required to authorize any transaction, meaning neither Capsule nor the integrating application can unilaterally spend funds. The complete key material is never reconstructed; signatures are produced cooperatively through distributed key generation.

Passkeys replace seed phrases as the primary authentication mechanism. Users authenticate with biometrics or device PINs through their platform's built-in secure enclave, which maps to an existing cryptographic standard broadly supported on modern iOS, Android, and desktop environments. Social login options — Google, email, phone number — can supplement passkeys for products targeting broader audiences. This combination is designed to make the initial wallet setup feel equivalent to creating a conventional app account while preserving non-custodial ownership semantics.

Solana Support

Capsule launched support for Solana embedded wallets in July 2024. The implementation extends the same MPC and passkey architecture to Solana's Ed25519 key system, allowing developers building AMMs, trading applications, on-chain games, and payments products on Solana to generate and manage wallet infrastructure without switching to a separate provider. Capsule provides both web and mobile SDKs for Solana integration, along with a quickstart guide and API key provisioning for developers beginning integration.

Solana support sits alongside more than 100 total supported chains. The platform provides native signing for EVM-compatible chains, Solana, Stellar, and Cosmos ecosystems, with multichain wallet management so a single wallet identity operates across all supported networks.

Cross-App Portability

The cross-app model is Capsule's primary differentiator against competing embedded wallet providers. Most embedded wallet services bind a wallet to the application that created it — the user has a wallet inside App A and a separate wallet inside App B, with no connection between them. Capsule stores wallets at the infrastructure level rather than the application level, meaning the same wallet can authenticate and sign inside any application that has integrated Capsule.

This portability works through a permissions model. Each integrated application receives granular transaction-level access to the wallet rather than full control. A user can grant one application permission to trade on a specific protocol while restricting another to read-only visibility, and neither application sees the raw key material. Wallet actions do not require the originating application to remain open; signing is handled through Capsule's infrastructure using distributed key generation, so the user's key share on their device cooperates with Capsule's share without any full key ever existing in a single location.

Developer Tools and Integration

Capsule provides SDKs for web, native mobile (iOS and Android), progressive web apps, Telegram mini-apps, Chrome extensions, and desktop environments. A Server SDK is available for backend-side wallet operations — a capability the company identifies as absent from most competing providers. An open-source MetaMask Snap also extends Capsule wallet functionality into the MetaMask browser extension context.

Money movement capabilities sit alongside the core wallet infrastructure. The platform includes APIs for on- and off-ramp, cross-chain bridging and token swaps, and stablecoin payment and payout flows. A permissions and policy engine allows developers to configure transaction-level access controls and compliance rules without building that logic themselves.

The developer pricing model includes a free tier for applications with up to 1,200 Monthly Active Users, intended to make evaluation accessible for early-stage teams. Usage-based paid tiers scale from there.

Security and Compliance

Capsule achieved SOC 2 Type II certification in January 2025. The MPC implementation has been independently audited by Least Authority, with audits completed in 2023 and 2024. The distributed key generation design is intended to eliminate the single-point-of-failure risk associated with competing approaches that recombine key shares in a centralized location before signing — an architectural distinction Capsule emphasizes against implementations using Shamir Secret Sharing or traditional secure enclaves.

Traction and Rebrand

By the time of the Para rebrand, Capsule reported more than 200 companies using the platform and 15 million end users with wallets protected by the infrastructure. The rebrand to Para in January 2025 was a name and brand change rather than a product pivot; the core wallet technology, engineering team, and customer base remained the same. The usecapsule.com domain permanently redirects to getpara.com, and all documentation and blog content migrated to the getpara.com domain.

Fit in the Solana Ecosystem

For Solana application developers, Capsule provides a route to deploy wallet onboarding that does not require users to hold SOL in an external wallet before interacting with the product. The cross-app portability model is particularly relevant for ecosystem builders: a wallet provisioned inside one Solana application carries over to others that have integrated the same infrastructure, reducing the fragmentation that arises when every dApp provisions independent wallets.

The non-custodial MPC design means that unlike fully custodial providers, users retain the ability to export their wallets independently of whether Capsule continues to operate, preserving a meaningful degree of self-custody even within the hosted infrastructure model.