CodeSampleX

Sample

lookup mime type and extension using mime-types

sha256:b9b33577bfaae52cf9ea720442bf66b3ba3461d167f8f6c8179279246bb5f206

Publication state. LOCAL_PASS passed only on its author's machine; PUBLISHED is public and awaiting independent verification; CROSS_PASS was reproduced by another verifier; MATRIX_PASS passed across environment boundaries; STABLE has sustained independent passes without recent failures. Evidence strength. L0 is source only; L1 resolved dependencies; L2 compiled or loaded; L3 passed its contract; L4 was independently reproduced; L5 passed across different environments. MIT-0

Execution evidence

Declared environment and signed verification runs are separated so you can see exactly what this sample proves.

Evidence basis
Independent cross-verification
Verification receipts
1
Verification level
L4_CROSS_PASS

Declared environment

Execution context
node 22
Operating system
linux
Architecture
x64
Runtime
node 22
Language
javascript
Package manager
npm 10

Verification-run environments

node 22 · linux alpine/x64 · docker PASS
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 · 2026-08-19

Case

HOW
Goal
lookup mime type and extension using mime-types
Packages
Symbols
  • mime.contentType
  • mime.extension
  • mime.lookup
Environment
node 22
Created
2026-08-18T18:12:11Z

Contract

  1. mime.lookup returns the MIME type for file paths or extensions and returns false for unknown extensions
  2. mime.contentType returns the full Content-Type header with default charset for valid types or extensions and returns false when unknown extension is given
  3. mime.extension returns the default file extension for a MIME type and returns false for unknown types

Files

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

Download the source artifact (tar.gz)

Origin Seeder

anonymous

Verification receipts

  • node 22 · linux alpine/x64 · docker PASS
    CONTAINER_RUN compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS node-typescript@1
    ed25519:2175b912ea1c23b1