Response Extraction

Extraction rules let you automatically pull values out of HTTP responses and save them as environment variables. Once configured, rules run after every send -- no manual copy-pasting needed. This is the foundation for request chaining, where one request's output feeds into the next request's input.

Configuring Extraction Rules

You configure extraction rules in the Extract tab of the Response panel. Each rule has three parts:

1. Source: Where to extract from (body, header, status, or cookie).
2. Path or name: The specific value to extract (a JSON path, header name, or cookie name).
3. Variable name: The environment variable to save the extracted value into.

Rules are saved per request and persist across sessions. Every time you send the request, the rules execute against the new response and update the environment variables.

Sources

Body (JSON Path)

Extract a value from a JSON response body using dot notation. Array indices use bracket notation.

JSON Path	Response Body	Extracted Value
data.token	{"data": {"token": "abc123"}}	abc123
data.user.name	{"data": {"user": {"name": "Alice"}}}	Alice
items[0].id	{"items": [{"id": 42}, {"id": 43}]}	42
meta.pagination.next	{"meta": {"pagination": {"next": "/page/2"}}}	/page/2

Paths are evaluated against the parsed JSON. If the path does not resolve to a value (e.g., the key is missing or the response is not valid JSON), the extraction is skipped and the environment variable is not updated.

Header

Extract the value of a response header by name.

Header Name	Extracted Value Example
Content-Type	application/json; charset=utf-8
X-Request-Id	req-7f3a2b1c
X-RateLimit-Remaining	42
Location	https://api.example.com/resources/123

Header name matching is case-insensitive. The full header value string is stored in the environment variable.

Status

Extract the HTTP status code as a numeric string.

Response Status	Extracted Value
200 OK	200
201 Created	201
404 Not Found	404

This is useful for conditional logic in pre-request scripts that check the outcome of a previous request.

Cookie

Extract a cookie value by name from the response's Set-Cookie headers.

Cookie Name	Extracted Value Example
session_id	s%3Aabc123.xyz
csrf_token	d4f7a2b1c3e8

Only the cookie value is extracted, not the attributes (Path, Expires, HttpOnly, etc.).

Rule Configuration Example

Here is how three extraction rules might be configured for a login endpoint:

Source	Path / Name	Variable Name
Body	data.token	authToken
Body	data.user.id	userId
Header	X-Request-Id	lastRequestId

After sending POST /login, LitePost extracts the token and user ID from the JSON body and the request ID from the headers, saving each to the specified environment variable. Any subsequent request can reference these as , , and .

Request Chaining Workflow

Extraction rules are most powerful when used to chain requests together. Here is a concrete three-step example.

Step 1: Authenticate

POST /auth/login

Request body:

{
  "email": "alice@example.com",
  "password": "{{testPassword}}"
}

Extraction rules on this request:

Source	Path	Variable Name
Body	data.token	authToken
Body	data.user.id	userId

After this request completes, the environment now contains authToken and userId.

Step 2: Fetch User Profile

GET /users//profile

Headers:

Authorization: Bearer {{authToken}}

The URL substitutes (extracted in Step 1), and the Authorization header substitutes (also from Step 1).

Extraction rules on this request:

Source	Path	Variable Name
Body	data.profile.orgId	organizationId

Step 3: List Organization Resources

GET /orgs//resources

Headers:

Authorization: Bearer {{authToken}}

This request uses from Step 2 and from Step 1, completing a three-step chain where each request depends on data from the previous one.

Extraction in the Collection Runner

When you execute a collection through the Collection Runner, extraction rules on each request run in sequence. This means you can build entire workflows:

1. The runner sends the first request and executes its extraction rules.
2. The extracted values are written to the environment immediately.
3. The next request in the collection picks up those values via substitution.
4. This continues through every request in the collection.

Because the environment is shared and updated in real time, a collection can implement complex multi-step API workflows -- authentication, data creation, verification, and cleanup -- all in a single automated run.

TIP

Pair extraction rules with test assertions to both validate and capture response data in one step. For example, assert that data.token exists, then extract it into an environment variable.