ToIP
Also called Trust over IP, Trust over IP Foundation, ToIP stack
ToIP is a layered model for describing trust systems, in the way the OSI model describes networks: a shared way to say which problem you are solving without arguing about the whole stack at once.
The four layers, and why the split helps
Utilities at the bottom, agent-to-agent communication above them, credential exchange above that, and application ecosystems on top. The value is separation: a disagreement about a credential format is a layer-three disagreement and does not have to reopen the question of which ledger anyone uses.
The half people forget
Each technical layer has a governance counterpart. The model's claim is that a trust system needs both, and that most failures are governance failures wearing technical clothes. That is the part worth taking seriously even if the stack is never cited.
Where Solidus sits
Aligned in shape, uncertified in fact. Useful for explaining architecture to someone who already speaks it, and not a thing we can claim to hold.
Where it comes from
Someone else specified this. Solidus assembles it.
Trust over IP Foundation, under LF Decentralized Trust. It publishes an architectural model rather than a wire protocol: a four-layer stack separating utilities, agents, credentials and ecosystem governance, plus governance framework templates. Solidus did not contribute to it.
How to check this
Solidus has not built this. The entry explains the concept.
The model and its governance templates are public at trustoverip.org. What Solidus can show is architecture that maps onto the layers, which is a description rather than a credential.