Dev Proxy

LLM usage costs are unpredictable without detailed telemetry. Dev Proxy logs OpenAI usage in OpenTelemetry, tracking tokens, requests, and costs. Get session-level insights to optimize prompts and control spending.

See how: learn.microsoft.com/microsoft-cl...

Dev Proxy v1.0 with new features for building robust AI-powered apps - Microsoft 365 Developer Blog Introducing Dev Proxy v1.0, with new language model-specific testing capabilities to help developers build more reliable AI-powered applications by simulating real-world scenarios and tracking resourc...

We’re excited to announce Dev Proxy v1.0, with new language model-specific testing capabilities. Check it out! devblogs.microsoft.com/microsoft365...

Apps using large language models risk errors - like biased or confusing responses - leading to broken workflows or reputational harm. Dev Proxy lets you simulate LLM failures in development, so you can test and improve your app's error handling.

See how: learn.microsoft.com/microsoft-cl...

Simulate a CRUD API across the internet - Dev Proxy How to simulate a CRUD API across the internet.

Need a mock API which is also available over the internet? Dev Proxy lets you simulate CRUD APIs instantly with no code, share live endpoints via Dev Tunnels, validate early, collaborate remotely, and speed up frontend integration.

Learn more: learn.microsoft.com/microsoft-cl...

Simulate a CRUD API secured with Microsoft Entra - Dev Proxy How to simulate a CRUD API secured with Microsoft Entra

Integrating APIs secured with Microsoft Entra but don't have the complete configuration yet? Don't wait! Dev Proxy's `CrudApiPlugin` simulates CRUD APIs with Entra auth and scope-based permissions, speeding up testing and reducing integration risks.

Check it out: learn.microsoft.com/microsoft-cl...

Screenshot showing mock data setup for a Microsoft Graph API response. On the left, a JSON file defines a mock GET response for https://graph.microsoft.com/v1.0/me, with user details like name and email. On the right, the terminal displays the mocked response being served from a local proxy.

Testing your app against real-world failures can be a pain. Especially when working with APIs that you don't own like Microsoft Graph. 1/4

In this video, we walk you through installing and running Dev Proxy on your machine for the first time using the Dev Proxy Toolkit extension for Visual Studio Code. ==== Dev Proxy is an API simulator that helps you effortlessly test your app beyond the happy path. Learn more: aka.ms/devproxy Get started with Dev Proxy

Ready to see how your app handles real API errors? Watch the quick start video and try Dev Proxy today: youtu.be/HVTJlGSxhcw?... 4/4

You'll spot error handling problems before production hits. No more guessing how your app reacts when the API fails. 3/4

GraphMockResponsePlugin - Dev Proxy GraphMockResponsePlugin reference

The GraphRandomErrorPlugin lets you simulate random Microsoft Graph errors-like 429, 500, and 503-right in your environment. 2/4

learn.microsoft.com/microsoft-cl...

Screenshot showing mock data setup for a Microsoft Graph API response. On the left, a JSON file defines a mock GET response for https://graph.microsoft.com/v1.0/me, with user details like name and email. On the right, the terminal displays the mocked response being served from a local proxy.

Testing your app against real-world failures can be a pain. Especially when working with APIs that you don't own like Microsoft Graph. 1/4

In this video, we walk you through how to use Dev Proxy to simulate Azure OpenAI APIs responses using locally running language models (Ollama). === Dev Proxy is an API simulator that helps you effortlessly test your app beyond the happy path. Learn more: https://aka.ms/devproxy Simulate Azure OpenAI APIs with Dev Proxy and local language models

Try simulating OpenAI API calls with Dev Proxy today. 4/4

youtu.be/RKCeKUMUFWk?...

You can work offline, run tests, and skip unnecessary API calls-all while cutting costs and staying focused on building. 3/4

OpenAIMockResponsePlugin - Dev Proxy OpenAIMockResponsePlugin reference

Dev Proxy lets you simulate OpenAI API responses using a local language model. No wasted tokens. No waiting. 2/4

learn.microsoft.com/microsoft-cl...

Terminal screenshot showing OpenAIMockResponsePlugin in use, with commands to run/stop proxy and a POST request to OpenAI API. Red arrows highlight 'Call cloud LLM' and 'Get local response'.

Building with OpenAI APIs can get expensive fast-especially when you just need to test parts of your app that don't need real AI replies. 1/4

Demo: Simulate random error responses from Microsoft 365 APIs This sample contains a demo web application connected to Microsoft Graph. Using Dev Proxy, you can simulate random errors returned by Microsoft Graph and see how the app handles them.

Apps often break with random API errors, as testing only "success" hides bugs. Dev Proxy lets you simulate Microsoft Graph API errors, testing your app's resilience before users do. Check out this sample to see it in action: adoption.microsoft.com/en-us/sample...

Unpredictable API errors slow dev and frustrate users. Dev Proxy's GenericRandomErrorPlugin simulates API failures with configurable error types and rates-no code changes needed. Uncover bugs, boost reliability, and cut manual test time.

Try it on your app: learn.microsoft.com/microsoft-cl...

Simulate rate limiting on Microsoft Graph APIs This sample contains a preset to simulate rate limiting on Microsoft Graph APIs. Selected Microsoft Graph endpoints support rate limiting, which is a mechanism that informs developers of the available...

Worried about Microsoft Graph rate limits? Use Dev Proxy's sample to simulate throttling locally, test your app's behavior, fine-tune error handling, and ship confident your app won't break under real-world limits. Try it before you deploy! adoption.microsoft.com/sample-solut...

Integrating with GitHub APIs? Test GitHub API rate limits safely with Dev Proxy's GitHub Rate Limiting sample. Simulate throttling, catch issues early, and ensure your app stays reliable. Try it here: adoption.microsoft.com/sample-solut...

Unexpected API rate limits, especially with custom status codes, can hinder development and trust. Dev Proxy simulates rate-limit responses in your workflow, letting you test and validate app resilience before production. Integrate confidently.

Check it out: learn.microsoft.com/microsoft-cl...

Still waiting for the API webhook? Don't! Dev Proxy's MockRequestPlugin lets you trigger customizable web requests instantly, speeding up testing, debugging, and integration-no setup required.

Check it out: learn.microsoft.com/microsoft-cl...

Mock responses that return binary data - Dev Proxy How to mock responses that return binary data

Integrating APIs that return binary data is hard without test endpoints, slowing development and complicating automation. Dev Proxy solves this by letting you mock binary responses from local files, saving you precious time!

Check it out: learn.microsoft.com/microsoft-cl...

Building with unreliable third-party APIs wastes time on setup, debugging, and mock creation. Dev Proxy's Northwind sample offers ready-made CRUD APIs with real data-test all flows early, skip guesswork, and build faster.

Check it out: adoption.microsoft.com/sample-solut...

Full CRUD API in minutes, no backend needed. Dev Proxy's `CrudApiPlugin` simulates interactive CRUD endpoints with an in-memory store via simple config-no mock servers needed. Test integrations fast and unblock your team.

Try it: learn.microsoft.com/microsoft-cl...

Testing APIs with varying responses by request order is tedious and error-prone. Dev Proxy's "Mock nth request" lets you easily simulate different responses per request. Validate edge cases faster, improve confidence, and simplify testing workflows.

Check it out: learn.microsoft.com/microsoft-cl...

Testing integrations with real APIs is tricky. Manually setting unique responses for every query is tedious. Dev Proxy streamlines this: mock multiple responses per endpoint, control match precision, and debug easily for smoother API testing.

Check it out: learn.microsoft.com/microsoft-cl...

New Dev Proxy beta v1.0.0-beta.7 with:
- configurable OIDC metadata URL in the AuthPlugin
- fixed bugs in RateLimitingPlugin and ApiCenterMinimalPermissionsPlugin

Try it: learn.microsoft.com/microsoft-cl...

Mocking APIs doesn't need to be hard. At least, as long as you use Dev Proxy. See for yourself: github.com/pnp/proxy-sa...

Manual mock creation for API tests is slow and error-prone. Dev Proxy's MockGeneratorPlugin records real API traffic, auto-generates accurate mocks, and saves them for reuse, speeding up integration testing. No more manual work!

See for yourself: learn.microsoft.com/microsoft-cl...

Testing the real Microsoft Graph API is slow and unpredictable. Dev Proxy's Graph Docs Mocks simulate API requests via docs-based mock files. Get reliable test data-no production data needed. Spot issues early with Dev Proxy.

Check it out: adoption.microsoft.com/sample-solut...

Waiting for backend APIs slows front-end development. Dev Proxy's mock feature lets you emulate any API without code changes-define custom responses, use wildcards, and serve data instantly. Build, test, and iterate confidently, free from API delays

Check it out: learn.microsoft.com/microsoft-cl...