API Inspector User Manual

Welcome to API Inspector, a modular API testing and analysis tool designed for developers and QA engineers.

Installation

Requirements

• .NET 9 runtime
• Windows 11 or later

Installer uses Inno Setup modern wizard style installation. The installer will automatically install the .NET 9 runtime if necessary.

Core Command‑Line Options Sysadmins Commonly Use

Silent / Unattended Installation

Silent install (no UI):

setup.exe /silent

Very silent (no UI, no progress window):

setup.exe /verysilent

Suppress reboot:

setup.exe /norestart

Force reboot if needed:

setup.exe /restart

Exclude desktop icon

setup.exe /TASKS="!desktopicon"

Override installation directory:

setup.exe /DIR="C:\Tools\API_Inspector"

Override Start Menu folder:

setup.exe /GROUP="API Tools"

Log installation

setup.exe /LOG="C:\Logs\api_inspector_install.log"

Silent uninstall:

"C:\Program Files\API_Inspector\unins000.exe" /silent

This example installs API Inspector silently, adds it to PATH, and logs the process:

API_Inspector_Setup.exe /verysilent /norestart 
 /TASKS=addtopath /LOG="C:\Logs\api_inspector.log"

Quick Start

1. Create a new project folder.
2. Launch API Inspector.
3. Enter your credentials.
4. Send an example request.
5. Add assertions for the request.
6. Set the working folder.
7. Save your tests.
8. You should now have test1.json and credentials.json in the working folder.

Application Sections

Request Editor

The Request Editor includes:

• A dropdown for selecting the HTTP method
• A textbox for the URL
• A Send button
• A result panel showing the returned content or any error
• A body textbox for requests that require a payload (e.g., POST)

The Request view contains a dropdown for selecting the HTTP method, a textbox for the URL, and a Send button.
The result textbox shows the returned content or any error message.
The body textbox is used for requests that include a payload, such as POST.

HTTP Methods Summary

• GET
  Retrieve a resource. No body. Safe and idempotent.

• POST
  Create a new resource or trigger an action. Request body usually required.

• PUT
  Replace an existing resource entirely. Idempotent.

• PATCH
  Partially update an existing resource. Not necessarily idempotent.

• DELETE
  Remove a resource. Idempotent in practice.

An operation is idempotent if applying it multiple times has the same effect as applying it once.

Log View

The Log View contains:

• A grep‑style search box
• The log output panel

Logs can grow large and difficult to navigate, so several features help keep them manageable:

• Each request is tagged with an Activity ID, a random number that helps you distinguish between requests.
• Fast scrolling with ALT + mouse wheel lets you move quickly through long logs.
• The grep‑style search allows you to filter and focus on specific entries.

Assertions

You can create simple assertion tests without coding.
To test a JSON value, use:

$.value equals expectedValue

You can add multiple assertions per request to validate different parts of the response. Typical checks include:

• Status code is expected (for example 200)
• JSON property equals a specific value
• JSON property exists
• Response body contains expected text

If an assertion fails, the test is marked as failed and the failure is shown in test results/logs.

Headers

Use Headers to add key/value metadata to the request.

Common examples:

• Authorization: Bearer <token> for authenticated endpoints
• Content-Type: application/json when sending JSON in the request body
• Accept: application/json when you want JSON responses

Notes:

• Header names are case-insensitive, but values are exact
• Missing required headers may cause 400 or 401 responses
• Custom headers are supported and saved with the request

Query Params

Query parameters are appended to the URL after ? and are used to filter or control results.

Example:

• URL: /api/tests?project=Core&status=passed&page=2
• project=Core filters by project
• status=passed filters by result status
• page=2 selects a specific page

Rules:

• Separate parameters with &
• URL-encode special characters when needed (for example space = %20)
• Query params are sent as part of the URL and are visible in logs/history

Test Explorer

Allow you to run all tests. Including subfolders ones.

Test Explorer scans the working folder and subfolders for saved test files. From this view you can:

• Run all discovered tests
• Run a single test file
• See pass/fail status after execution
• Quickly identify failed tests for re-run

Use this view to validate large test sets in one action before committing changes.

Authorisation

You can change authorisation settings here.
Settings are saved in the working folder in a file called credentials.json.

Typical use:

• Set bearer token credentials
• Update credentials when environments change (dev/test/prod)
• Reuse saved credentials across requests in the same working folder

Keep credentials.json secure and avoid committing sensitive values to source control.

Settings

The Settings view allows you to customise the behaviour of the application.

Examples of configurable behaviour include:

• Application theme
• Working folder defaults
• UI and usability preferences

Settings are intended to persist your preferred workflow between sessions.

API Inspector Command Line Tool

A command-line version of the API Inspector that allows you to execute API tests from .api files.

Features

1. Search for API files - Recursively searches for *.api files in a directory
2. Load credentials - Loads credentials from credentials.json in the search directory or AppData
3. Execute tests - Runs tests defined in each API file
4. Log output - Writes detailed logs to the current directory with timestamps
5. Display results - Shows test execution summary and returns appropriate exit codes
6. Exit codes:
   • 0 - All tests passed
   • 125 - One or more tests failed
   • 1 - Fatal error

Usage

Inspector [searchPath]

Arguments

• searchPath (optional): Directory to search for *.api files. Defaults to the current directory.

Examples

Run tests in current directory:

Inspector

Run tests in a specific folder:

Inspector "C:\Tests\Api"

Use the CLI in CI/CD pipelines and check the process exit code to fail builds when tests fail.

Version History and Updates

0.7 - 31.5.2026

• Added: Variables are now supported
• Added: Query Params view
• Added: Quick assertion creation
• Change: Speed improvements for large responses
• Change: Log file is now writen AppData
• Fix: More logging improvements
• Fix: Ctrl+R din't work.
• Fix: SyntaxHiliteBox logic fixes.
• Fix: Typing a header name that is not in the autocomplete list now persists and gets saved correctly.

0.6 - 6.5.2026

• Proxy support
• Syntax highlighting
• Http version selection
• Trace/options http verb
• Import/Export cUrl

0.5 - 19.4.2026

• Test Explorer
• Custom headers
• Multilingual support
• AutocompleteComboBox
• Dark mode support
• Bug fix: Unsaved Changes Warning

0.4 - 25.3.2026

• Credidentals are now loaded working folder: credentials.json
• Command-line tool
• Manual
• Updated log4net and system.management packages
• Open working folder and help commands
• Bug Fix: Authorisation

0.3 - 25.2.2026

• Assertions
• Save / load tests
• Fast log scrolling
• Remember previous view at startup
• Cycle views Ctrl+Tab

0.2 - 4.1.2026

• JSON Formatter / Beautifier
• Hotkey for Send button
• Auto update
• Save / Load window position
• Grep-like search

0.1 - 20.11.2025

• First version