CONTROL THE CONDITIONS

Install the API you need to test. Switch its behaviour on demand.

Choose one mock module for your provider API, point your integration at its stable endpoint, then change between success and failure behaviours whenever you need them.

Inspect the real request your integration sent and the controlled response it received.

Start testing Explore modules

CONTROLLED RESPONSESALESFORCE LEAD API

POST /services/data/v66.0/sobjects/Lead

401INVALID_SESSION_ID

{
  "message": "Session expired or invalid",
  "errorCode": "INVALID_SESSION_ID"
}

Switch to success on the same endpoint

PROVIDER MODULE CATALOGUE

Seven APIs. The outcomes you need to exercise.

Each module has operations and provider-shaped behaviours. Install a module once, then choose its operation and response. Fidelity is labelled at the behaviour level.

CRM

Salesforce Lead API

Salesforce

Sales Cloud REST API Lead create and representative provider responses.

1 operation · 9 behaviours

Create Lead

HubSpot Contacts API

HubSpot

Contacts create/update, CRM validation, permissions and API usage behavior.

2 operations · 16 behaviours

Create Contact · Update Contact

Microsoft Dataverse Accounts API

Microsoft Dynamics 365 / Dataverse

Dataverse Web API table row operations and service-protection responses.

2 operations · 14 behaviours

Create Account · Update Account

Marketing

Convertr Campaign Webhook

Convertr

Campaign Webhook lead submission with documented API-key query auth, form fields and response outcomes.

1 operation · 8 behaviours

Submit Lead

AI

OpenAI Responses API

OpenAI

Responses API JSON, semantic SSE events, authentication, rate limits and quota outcomes.

3 operations · 12 behaviours

Generate Response · Stream Response · Tool Call

Anthropic Messages API

Anthropic

Messages API JSON and SSE lifecycle, validation, overload and timeout outcomes.

3 operations · 16 behaviours

Create Message · Stream Message · Tool Use

Google Gemini Interactions API

Google Gemini

Gemini Interactions API generation, SSE, safety blocks and tool-call outcomes.

3 operations · 15 behaviours

Generate Interaction · Stream Interaction · Tool / Function Call

HOW IT WORKS

Point your client at one endpoint.

01 · Install

Choose the provider API module and copy its receiver URL into your development configuration.

02 · Switch

Select an operation and a success, failure, delay or stream behaviour. The receiver URL stays the same.

03 · Inspect

Run your integration and review captured method, path, headers, body and response status.

MORE CONTROL

Build your own HTTP response when you need one.

Generic Mock remains available for internal APIs and custom response rules. Capture endpoints let you inspect incoming requests without a provider module.

GENERIC MOCK

You set the HTTP behaviour.

Choose a method and path, then control status, body, headers, delay or event stream.

PROVIDER MODULE

Start with a provider-shaped response.

Choose from documented, representative and clearly marked synthetic outcomes.

BEFORE PRODUCTION

Test the failure path before your customer does.

Start your 7-day free trial and make the next failure repeatable.

Start testing

NotTheRealAPI is independent and is not affiliated with or endorsed by the providers named here.