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Sample

express 5.1.0: Enable express trust proxy to resolve client IP, HTTPS protocol, and forwarded host behind reverse proxies without silently ignoring X-Forwarded headers

Verified sample for npm express 5.1.0: Enable express trust proxy to resolve client IP, HTTPS protocol, and forwarded host behind reverse proxies without…

sha256:91407f3e83bfceb9b5d36d67130853425cc7c6e45d5ac8532a6043cae432b0a7

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
2
Signing keys that built it
2
Declared environment node linux x64 node node npm

Verification-run environments

Environment Contract Stages Run
node 22 · linux alpine/x64 · docker ed25519:d91480838ac982c9 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1
2026-08-16
node 22 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1
2026-08-18

Case

HOW
Goal
Enable express trust proxy to resolve client IP, HTTPS protocol, and forwarded host behind reverse proxies without silently ignoring X-Forwarded headers
Packages
Symbols
  • express
  • app.set
  • req.ip
  • req.ips
  • req.protocol
  • req.secure
  • req.hostname
Environment
node
Created
2026-08-16T06:30:14Z

Contract

  1. start express app without trust proxy and verify req.ip ignores X-Forwarded-For
  2. start express app with trust proxy loopback and verify req.ip extracts client IP
  3. verify req.ips contains upstream client IP chain
  4. verify req.protocol evaluates to https from X-Forwarded-Proto
  5. verify req.secure evaluates to true when proxied over https
  6. verify req.hostname extracts domain from X-Forwarded-Host
  7. start express app with subnet trust proxy and verify multi-hop X-Forwarded-For chain extraction

Files

  • NOTES.md
  • csx.json
  • package-lock.json
  • package.json
  • src/app.mjs
  • test/contract.mjs

Download the source artifact (tar.gz)

Origin Seeder

csx-seed