A Timestamp Identifier (TID) is a compact, sortable string identifier based on an integer timestamp. TIDs are used throughout the network to establish time ordering, serving as unique chronological identifiers for record and repository commits while remaining URL-friendly.
Each TID is a 64-bit integer with a specific bit layout:
TIDs use a base32-sortable encoding with the character set:
234567abcdefghijklmnopqrstuvwxyz
The encoding always produces exactly 13 ASCII characters with no padding characters, while maintaining lexicographic sorting (alphabetical sorting matches timestamp ordering).
For example, a TID might look like 3jzfcijpj2z2a
Unlike centralized systems with coordinated ID generation, the AT Protocol operates in a decentralized environment where global uniqueness cannot be guaranteed. Repository controllers could theoretically create records using their own TIDs, though this is generally considered adversarial behavior.