Saving responses in Postman

Introduction

Saving responses helps you keep a record of what your API sends back. This makes it easy to check results later or share them with your team.

You want to compare current API results with past results to find changes.

You need to share API responses with teammates for debugging or review.

You want to keep examples of responses for documentation.

You want to test how your app handles different API responses by saving and reusing them.

You want to save responses to use in automated tests later.

Syntax

Postman

pm.test('Save response', function () {
    let responseBody = pm.response.text();
    pm.environment.set('savedResponse', responseBody);
});

pm.response.text() gets the full response as text.

pm.environment.set() saves data in Postman environment variables for reuse.

Examples

This saves the JSON response as a string in an environment variable called userData.

Postman

pm.test('Save JSON response', function () {
    let jsonData = pm.response.json();
    pm.environment.set('userData', JSON.stringify(jsonData));
});

This saves only the id field from the JSON response.

Postman

pm.test('Save specific field', function () {
    let jsonData = pm.response.json();
    pm.environment.set('userId', jsonData.id);
});

This saves the Content-Type header value from the response.

Postman

pm.test('Save response header', function () {
    let contentType = pm.response.headers.get('Content-Type');
    pm.environment.set('contentType', contentType);
});

Sample Program

This test saves the entire response body into an environment variable named fullResponse. It also checks that the response is not empty.

Postman

pm.test('Save full response body', function () {
    let responseBody = pm.response.text();
    pm.environment.set('fullResponse', responseBody);
    pm.expect(responseBody).to.not.be.empty;
});

Important Notes

Saved responses are stored as strings. Use JSON.parse() to convert back to objects if needed.

Environment variables are shared across requests in the same environment. Use collection or global variables if needed.

Remember to clear saved variables if they are no longer needed to avoid confusion.

Summary

Saving responses helps keep track of API outputs for later use.

You can save full responses or specific parts like fields or headers.

Use Postman scripts with pm.environment.set() to save data during tests.

Practice

1. What is the main purpose of saving responses in Postman?

easy

A. To speed up the API server

B. To delete old API requests automatically

C. To keep track of API outputs for later use

D. To change the API endpoint URL

Solution

1. Step 1: Understand the role of saving responses

   Saving responses allows testers to keep the output data from API calls for future reference or validation.

2. Step 2: Identify the correct purpose

   Among the options, only keeping track of API outputs matches the purpose of saving responses.

3. Final Answer:

   To keep track of API outputs for later use -> Option C

4. Quick Check:

   Saving responses = keep API outputs [OK]

Hint: Saving responses means storing API outputs for reuse [OK]

Common Mistakes:

• Confusing saving responses with deleting requests
• Thinking it speeds up the server
• Assuming it changes API URLs

2. Which Postman script command is used to save a value from a response into an environment variable?

easy

A. pm.response.save()

B. pm.environment.set()

C. pm.request.store()

D. pm.variable.get()

Solution

1. Step 1: Recall Postman scripting commands

   To save data into environment variables, Postman uses the command pm.environment.set(variableName, value).

2. Step 2: Match the command to the options

   Only pm.environment.set() correctly saves a value into an environment variable.

3. Final Answer:

   pm.environment.set() -> Option B

4. Quick Check:

   Save to environment = pm.environment.set() [OK]

Hint: Use pm.environment.set() to save response data [OK]

Common Mistakes:

• Using pm.response.save() which does not exist
• Confusing get() with set()
• Trying to save with pm.request.store() which is invalid

3. Given this Postman test script, what will be the value saved in the environment variable 'userId' if the response JSON is {"id": 42, "name": "Alice"}?

let jsonData = pm.response.json();
pm.environment.set('userId', jsonData.id);

medium

A. 42

B. null

C. undefined

D. "Alice"

Solution

1. Step 1: Parse the response JSON

   The response JSON has an "id" field with value 42 and a "name" field with "Alice".

2. Step 2: Check the script saving the value

   The script saves jsonData.id into 'userId', so it saves 42.

3. Final Answer:

   42 -> Option A

4. Quick Check:

   jsonData.id = 42 [OK]

Hint: jsonData.id saves the number 42 from response [OK]

Common Mistakes:

• Saving the name instead of id
• Assuming undefined if JSON parsing fails
• Confusing string and number values

4. You wrote this test script to save a token from response but it does not save correctly:

let jsonData = pm.response.json();
pm.environment.set('token', jsonData.token);

What is a likely reason the token is not saved?

medium

A. The response does not contain a 'token' field

B. pm.environment.set() is not a valid function

C. You must use pm.response.save() instead

D. The variable name 'token' is reserved

Solution

1. Step 1: Check the response JSON fields

   If the response JSON does not have a 'token' field, jsonData.token will be undefined.

2. Step 2: Understand saving undefined values

   Saving undefined means the environment variable 'token' will not be set correctly.

3. Final Answer:

   The response does not contain a 'token' field -> Option A

4. Quick Check:

   Missing field = no saved value [OK]

Hint: Check response fields before saving variables [OK]

Common Mistakes:

• Thinking pm.environment.set() is invalid
• Using non-existent pm.response.save()
• Assuming variable names are reserved

5. You want to save the 'sessionId' from a nested JSON response:

{
  "user": {
    "id": 10,
    "session": {
      "sessionId": "abc123"
    }
  }
}

Which script correctly saves 'sessionId' into an environment variable?

hard

A. let jsonData = pm.response.json(); pm.environment.set('sessionId', jsonData.user.session['id']);

B. let jsonData = pm.response.json(); pm.environment.set('sessionId', jsonData.sessionId);

C. let jsonData = pm.response.json(); pm.environment.set('sessionId', jsonData.user.sessionId);

D. let jsonData = pm.response.json(); pm.environment.set('sessionId', jsonData.user.session.sessionId);

Solution

1. Step 1: Analyze the JSON structure

   The 'sessionId' is inside user > session > sessionId.

2. Step 2: Match the correct path in script

   Only jsonData.user.session.sessionId correctly accesses the nested 'sessionId'.

3. Final Answer:

   let jsonData = pm.response.json(); pm.environment.set('sessionId', jsonData.user.session.sessionId); -> Option D

4. Quick Check:

   Nested access = jsonData.user.session.sessionId [OK]

Hint: Use full path for nested JSON fields [OK]

Common Mistakes:

• Accessing sessionId directly from jsonData
• Using wrong nested keys
• Confusing sessionId with user id