Postman Environment Variables: Current Value vs Initial Value disparity in Newman

Answer (to the question)

In a headless Newman run, the value field inside an exported environment JSON wins. Newman loads the environment once, copies every variable’s value into memory, and ignores any current_value that may also be present. The current_value key is only used by the Postman desktop app to keep a local override; it is not considered by the Newman CLI.

Why This Happens (Confirmed Facts)

• Newman parses the environment file with JSON.parse and builds an in‑memory map of variables using the value key.
• During a run, any assignment via pm.environment.set updates that in‑memory map only; the source file stays unchanged unless you use --export-environment.
• The console output shows the value that was in effect at the time of each request, which will always be the value from the in‑memory map.
• Because current_value is not part of the map, it never influences runtime resolution.

How to Verify This Safely

1. Create a Non‑Sensitive Test Environment
   

   {
     "id": "test-env",
     "name": "Test Env",
     "values": [
       {"key": "demoVar", "value": "initial", "current_value": "override"}
     ]
   }

2. Run Newman
   

   newman run collection.json -e test-env.json

   The console will print demoVar: "initial" for each request, showing that the value was used.

3. Export the Final State (Optional)
   

   newman run collection.json -e test-env.json --export-environment exported.json

   Open exported.json – it will contain "value": "initial" unless a test script changed it.

4. Check for Overrides in Scripts
   

   If a pre‑request script calls pm.environment.set('demoVar', 'updated'), subsequent requests will use "updated" and the exported file will reflect that change.

What to Ask Next

If you still see a mismatch between the value you expect and what Newman reports, confirm whether the environment file actually contains a current_value entry for that variable. The presence of current_value does not affect Newman, but it can be a source of confusion when reviewing the file.

Key Takeaway

During a Newman run, only the value field matters. Use a non‑secret placeholder or export the environment after the run to avoid leaking sensitive data.