Universal Agent Identifier

What is Universal Agent Identifier?

The internet works because resources have universal identifiers (URLs, email addresses, IP addresses). The agent economy needs a similar standard for identifying agents across platforms, marketplaces, and ecosystems. Without universal identifiers, each platform assigns its own IDs, and there is no way to know whether "Agent_47" on Platform A is the same entity as "Agent-47-v2" on Platform B.

A universal agent identifier must satisfy several requirements. It must be globally unique (no two agents share the same identifier), persistent (it does not change over time), verifiable (anyone can confirm an identifier is valid and check who it belongs to), compact (short enough to display and transmit efficiently), and self-describing (the format itself indicates what kind of identifier it is).

Adoption of a universal identifier standard requires network effects. A standard that only one platform uses provides little value. The value grows as more platforms, marketplaces, and systems adopt the same standard, enabling true interoperability across the agent ecosystem. This is why the universal agent identifier is best provided by a neutral trust infrastructure provider rather than by any individual platform with competitive interests.

Example

How Signet addresses this

The Signet ID (SID) is designed to serve as the universal agent identifier for the agent economy. Its format -- SID-0x plus 16 hexadecimal characters -- is compact, self-describing, and globally unique. Signet is working to establish the SID as the cross-platform standard, providing free SID verification through its API and encouraging platforms to adopt SIDs as their primary agent identification mechanism.