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HTTP CLIENT

Sending Requests

Everything about making HTTP requests — methods, URLs with variables, concurrent execution, HTTP/2 negotiation, SSL settings, and cURL import.

API Studio with a POST request and response side by side

HTTP Methods

Select the method from the dropdown left of the URL bar. All standard methods are built-in, plus you can type any custom method.

GET POST PUT PATCH DELETE HEAD OPTIONS CUSTOM

Methods are color-coded in the tab bar and sidebar for quick identification. The method dropdown is a native <select> for maximum compatibility.

URL Bar

Enter your endpoint URL. It supports:

Variables — Use {{base_url}}/users/{{id}}. Resolved from active environment, collection vars, or vault secrets.
Query params sync — Adding ?key=val in the URL auto-populates the Params tab, and vice versa. Bidirectional.
Protocol schemes — https://, http://, ws://, wss://, grpc://, grpcs://
Variable hover — Hover over a {{var}} to see its resolved value and source (env, vault, collection).
Resolved variable showing value and source

Resolved variable — shows value + source

Unresolved variable with Add Variable button

Unresolved — click "Add Variable" to create it

Send & Cancel

ActionHowNotes
SendClick Send or Cmd+EnterButton shows a loading spinner while in-flight
CancelClick the spinning button (becomes Cancel)Aborts the request immediately via AbortController
SSE StreamAuto-detected when response is text/event-streamButton becomes "Stop" — events shown live in Stream tab

Execution Pipeline

When you click Send, the request goes through this pipeline:

Auth inject → Pre-request script → Cookies attach → HTTP send → Cookies parse → Set Variables → Test rules → Test script → History save

Concurrent Requests

Multiple tabs can have in-flight requests simultaneously. Each tab has its own independent AbortController — cancelling one request doesn't affect others.

Each tab shows its own loading state independently
Responses are routed back to the correct tab via tabId
Closing a tab auto-cancels any in-flight request for that tab
SSE streams and WebSocket connections are also per-tab

HTTP/2 Auto-Negotiation

API Studio uses HTTP/2 when the server supports it, automatically falling back to HTTP/1.1 otherwise. No configuration needed.

The protocol used is shown in the Request tab of the response viewer (e.g. HTTP/2 or HTTP/1.1).

SSL & Certificates

SSL verification is enabled by default. For self-signed certificates during development:

Global toggle — Settings → uncheck "SSL Verification" to disable for all requests
Per-request — SSL verification is per-request (uses undici Agent), concurrent requests with different SSL settings don't interfere
Client certificates — Configure mTLS with client cert, private key, and CA bundle from the vault. Set at request, folder, or collection level with inheritance.

cURL Import

Paste a cURL command anywhere in the URL bar — API Studio automatically detects and parses it into a full request.

Supported flags

-X, --requestHTTP method
-H, --headerCustom headers
-d, --dataRequest body
-F, --formMultipart form-data
--jsonJSON shorthand
-u, --userBasic auth
--oauth2-bearerBearer token
-G, --getForce GET + query body
-b, --cookieCookie header
-A, --user-agentUser-Agent header

Example — paste this into the URL bar:

curl -X POST https://api.example.com/users \
  -H "Authorization: Bearer token123" \
  -H "Content-Type: application/json" \
  -d '{"name":"John","email":"john@example.com"}'

Cookies

API Studio has a built-in cookie jar that automatically stores and sends cookies across requests.

Automatic — Set-Cookie headers are parsed and stored per domain
Sent automatically — Matching cookies are attached to subsequent requests
Toggle — Settings → "Cookies Enabled" to disable the cookie jar
View & manage — Settings → Cookie Manager to see, edit, or clear stored cookies
Stored in — .openpost/cookies.json (workspace-local)

Next

Request Body → Parameters & Headers → Response Viewer →
Ko-fi