Sample
RFC 9562 UUIDv7 encodes 48-bit Unix epoch milliseconds in the most significant bytes for chronological sorting, while v1ToV6 and v6ToV1 provide lossless bidirectional conversion between UUIDv1 and sortable UUIDv6
sha256:3ede91be1ec866fb02f7ef628bc245da3c78a87a298ebb0182a2b8391ff9cb4c
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Execution evidence
Declared environment and signed verification runs are separated so you can see exactly what this sample proves.
Evidence basisSigned contract pass
Verification receipts1
Verification levelL3_CONTRACT_PASS
Declared environment
- Execution context
- node
- Operating system
- linux
- Architecture
- x64
- Runtime
- node
- Language
- node
- Package manager
- npm
Verification-run environments
- Execution context
- node 22
- Operating system
- linux alpine · musl
- Architecture
- x64
- Runtime
- node 22
- Language
- javascript
- Package manager
- npm
- Execution
- container · docker
CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-17
Case
- Goal
- RFC 9562 UUIDv7 encodes 48-bit Unix epoch milliseconds in the most significant bytes for chronological sorting, while v1ToV6 and v6ToV1 provide lossless bidirectional conversion between UUIDv1 and sortable UUIDv6 HOW
- Packages
-
uuid 14.0.1
- Environment
- node
- Created
- 2026-08-17T20:44:23Z
Commonly assumed
UUIDv1 strings sort chronologically by generation time, or converting between UUID versions requires manually decoding and recalculating timestamp fields
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- UUIDv7 encodes Unix epoch milliseconds in its first 48 bits, ensuring generated UUIDs sort lexicographically in chronological order across millisecond timestamps
- UUIDv7 extracts the exact 48-bit big-endian millisecond timestamp passed via options.msecs
- UUIDv7 with identical timestamps sorts strictly by sequence number
- v1ToV6 reorders UUIDv1 timestamp fields into high-mid-low order into a valid UUIDv6 that sorts chronologically
- v6ToV1 losslessly restores the original UUIDv1 from a UUIDv6 representation
- v1ToV6 and v6ToV1 accept either formatted UUID strings or 16-byte Uint8Array buffers and return the matching representation
- v7 throws Error when provided with a random byte array shorter than 16 bytes
- v1ToV6 and v6ToV1 throw TypeError on invalid UUID strings
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- test/contract.mjs
Download the source artifact (tar.gz)
Origin Seeder
csx-seed
Verification receipts
- node 22 · linux alpine/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-17 · ed25519:d91480838ac982c9