Signers

An io.sign vault can contain Mobile Signers, Virtual Signers, or a combination of both. Every signer has a weight that contributes to the vault threshold when that signer participates.

Compare signer types

	Mobile Signer	Virtual Signer
Decision source	A person using the io.sign mobile app	OPA or a custom policy server
Runtime	Supported iOS or Android device	Customer-controlled service infrastructure
Typical use	Human review, separation of duties, recovery roles	Automated workflows and continuously available policy enforcement
Key-share protection	Device security hardware and app authentication	Encrypted storage and the deployment's confidential-computing controls
Connectivity	io.sign API and signer messaging endpoints	io.sign API, signer messaging endpoints, and the configured policy engine

Combine human and automated signers

Signer types do not define signing power. Weight does. For example, a threshold-4 vault could give two Mobile Signers weight 2 each and one Virtual Signer weight 4. The people can sign together, while the automated signer can sign independently.

Design weights around the combinations your security policy intends to permit. See Vaults, signers, and thresholds before creating a production vault.

Mobile Signer

Use a Mobile Signer when a person should review requests and participate from a supported phone. The app stores the signer's share locally and uses device authentication when the user approves an operation.

Continue to Mobile Signer to install and register the app, or Connect to a custom environment when your io.sign service does not use the default environment.

Virtual Signer

Use a Virtual Signer when an automated policy should decide whether the signer participates. Virtual Signers directly support OPA and customer-operated policy servers.

Continue to Virtual Signer for architecture, deployment, and policy configuration.