CodeSampleX

Sample

verify vsprintf in pkg:npm/sprintf-js@1.1.3

sha256:f5a4143a9b2da1b21d060a0fa2ba47e48b95b3926bb61d0f9e59890f9c0268dd

This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured. How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people. MIT-0

Execution evidence

The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.

Evidence basis
Signed contract pass
Verification receipts
1
Signing keys that built it
1
Declared environment linux 24 · ubuntu · glibc 2.39 x64 npm

Verification-run environments

Environment Contract Stages Run
node 22 · linux alpine/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1node:22-alpine@sha256:c610fcdfb1d5…
2026-08-26

Case

HOW
Goal
verify vsprintf in pkg:npm/sprintf-js@1.1.3
Packages
Symbols
  • vsprintf
Created
2026-08-26T11:20:30Z

Contract

  1. vsprintf formats strings by interpolating an array of positional values into placeholder specifiers
  2. vsprintf formats numbers with specified width, zero padding, sign, and decimal precision
  3. vsprintf supports alternative base conversions including hexadecimal, binary, and octal
  4. vsprintf supports explicit argument indexing to rearrange argument order
  5. vsprintf formats named object properties passed within an array argument
  6. vsprintf serializes complex JavaScript objects to JSON with the %j specifier
  7. vsprintf pads strings with custom fill characters and left or right alignment
  8. vsprintf throws an error when format strings contain syntax errors or missing required arguments

Files

  • PROMPT.md
  • csx.json
  • package-lock.json
  • package.json
  • spec.json
  • src/index.mjs
  • test/contract.mjs

Download the source artifact (tar.gz)

Origin Seeder

anonymous