REST Client and diagrams

Test your APIs next to the code that calls them, and understand the system with architecture, flow, business, and database diagrams.

REST Client

The REST Client is an editor tab, right next to the code that calls the API. Debug a request and get back to the file in one click.

Open it

Right rail → More tools → REST Client. Its icon moves up to the rail while it's open.
Alt+9.
Tools → REST Client, or REST in the palette (Ctrl+Shift+A).

Collections

Collections and folders saved with the project, which you can rename.
Method selector, table of headers and parameters, body, and response view.
Variables with {{variable}}.
Requests generated from Spring endpoints.
Move / Copy to another project…
Next to each request's name, the status of its last response.

Multiple hosts per collection

Each request can go to:

Target	When
The URL as is	A specific request.
The project's local application	`localhost` with the port it started on.
Any of the defined hosts	Development, testing, staging…

Choose a default host per collection and change it per request, without editing the path or the parameters.

Accented characters without garbled symbols

Headers with accented characters are sent in ISO-8859-1 (the way Java, Node, and most servers read them), or in UTF-8 if you choose it per collection. Responses are read with the charset the server declares.

Certificates

For internal servers, mark their certificate as trusted. Yuli always asks for your confirmation first.

Contracts

Responses are validated against the contract. A rule that doesn't apply can be excluded for one field or for the whole contract, and restored from the list of exclusions.

Performance

The Quality panel's Performance tab shows the p50, p95, and p99 latency of REST Client requests.

The agent can create, send, and review requests with yuli_rest_*. Ask it to “test the orders endpoint with an id that doesn't exist”.

Diagrams

System diagrams open as a tab next to the editor: right rail → More tools → Diagrams, or Ctrl+Alt+D.

Tab	What it shows
System	Context: what it exposes and what it depends on.
Architecture	Layers and dependencies between components.
Flows	Each use case, step by step.
Business	Rules, queried data, and effects.
Code ↔ DB	Which DAOs and repositories call which functions, packages, and tables.

Classic Java applications

Servlets (web.xml), Struts 1 and 2 actions, and Spring MVC controllers come in as the entry layer. That way you see the complete flow: browser → action → service → DAO → database, with the business rules, including filters inside loops and the values of constants.

Method diagrams

Method flow and trace (Ctrl+Alt+F): an interactive flow graph.
Class and sequence diagrams for the method under the cursor.

Navigate and export

Fit to view, zoom at the cursor, and actual size.
Diagram export.
Diagram background: automatic (based on the theme) or white.

Mermaid in the chat

Mermaid diagrams written by the agent are rendered inside the chat.

Requirements and traceability

In the left rail, More tools → Requirements (Alt+Shift+R):

Import requirements documents and extract business rules, heuristically or with AI.
Rule ↔ test traceability: uncovered rules and orphan tests.
Alerts when a rule that's already covered changes.
Rule markers visible in the editor.