Semantic Substrate

What is Custody?

CustodyControlled holding of an asset or key on another's behalf, responsibility without ownership.

Custody is the primitive that answers who safely holds this? It names the party trusted to keep an asset or key secure for someone else.

It is the layer where responsibility is separated from ownership. Custody lets an agent hold what it does not own, under rules that protect the true owner.

Where custody sits in the stack

In the four-layer architecture of the agentic web, custody is a Substrate (L1) concept — it the cited foundation every layer grounds in. See the thesis for how the layers compound.

Custody in the portfolio

13 positions in the Semantic Substrate portfolio carry the Custody primitive10 available individually, 3 held as a coordinated set. Explore the Custody cluster →

Quick answers

What is Custody in agentic systems?
Controlled holding of an asset or key on another's behalf, responsibility without ownership.
Where does Custody sit in the agentic stack?
Custody sits at the Substrate (L1) layer — it the cited foundation every layer grounds in.
How many Custody domain positions exist in the Semantic Substrate portfolio?
13 positions carry the Custody primitive — 10 available individually, the rest held as a coordinated set.

Related primitives

Held in the portfolio under Custody.