Threshold APIs

@seams/wallet/threshold is the stable protocol-facing surface for applications that must reproduce threshold session-policy inputs or registration digests.

It exports:

• THRESHOLD_SESSION_POLICY_VERSION.
• buildEd25519SessionPolicy.
• computeEd25519SessionPolicyDigest32.
• the Ed25519SessionPolicy type.
• PRF_FIRST_SALT_V1 and PRF_SECOND_SALT_V1.
• computeThresholdEcdsaKeygenIntentDigest.

Keep policy construction at a trusted boundary. The digest binds authorization to the precise policy. Changing an input creates a different authorization object. Most browser integrations should let SeamsWeb own this work.

Read threshold signing before integrating this entrypoint directly.