Trust starts from a small set of seed agents named in the network's settings and grows by approval. When a trusted person approves someone's introduction, the introduced key becomes trusted too, and can in turn approve others. A key is accepted when there is a chain of approvals leading back to a seed, up to ten steps long.

An approval is itself a nanopublication: the approver states, with npx:approvesOf, the address of the introduction they vouch for. Nanodash offers it as an action where an unapproved introduction is shown.