dev-proxy

# Dev Proxy Dev Proxy is a command-line API simulator and proxy for testing how applications handle API failures, rate limits, latency, and more. It uses a plugin-based architecture configured through JSON configuration files. ## Prerequisites Before proceeding, verify that Dev Proxy is installed by running `devproxy --version`. If the command fails or Dev Proxy is not found: STOP — Read [references/installation.md](references/installation.md) for platform-specific installation instructions (macOS, Windows, Linux), first-run certificate setup, and verification steps. ## Quick Start Store all Dev Proxy files in `.devproxy/` in the workspace root. Start with: ```bash devproxy --config-file .devproxy/devproxyrc.json ``` STOP — Before creating or modifying any Dev Proxy configuration, read [references/best-practices.md](references/best-practices.md) for critical rules on file structure, plugin ordering, URL matching, and configuration patterns. ## Scenario Selection Identify the user's scenario and load the corresponding reference file for detailed instructions. ### Mock API Responses Return predefined responses, simulate CRUD APIs, mock MCP servers, or simulate authentication. **Plugins:** `MockResponsePlugin`, `CrudApiPlugin`, `GraphMockResponsePlugin`, `MockStdioResponsePlugin`, `AuthPlugin` STOP — Read [references/mock-api-responses.md](references/mock-api-responses.md) for mock file structure, matching rules, dynamic responses, CRUD API definitions, STDIO mocks, and auth simulation. ### Test API Resilience Simulate API failures, rate limits, throttling, and slow responses to verify error handling. **Plugins:** `GenericRandomErrorPlugin`, `GraphRandomErrorPlugin`, `RateLimitingPlugin`, `RetryAfterPlugin`, `LatencyPlugin` STOP — Read [references/test-api-resilience.md](references/test-api-resilience.md) for error injection configs, rate limiting setup, throttling simulation, and latency testing. ### Test LLM Applications Mock OpenAI/Azure OpenAI responses, simulate LLM failures, enforce token-based rate limits, and monitor usage. **Plugins:** `OpenAIMockResponsePlugin`, `LanguageModelFailurePlugin`, `LanguageModelRateLimitingPlugin`, `OpenAITelemetryPlugin`, `OpenAIUsageDebuggingPlugin`, `MockStdioResponsePlugin` STOP — Read [references/test-llm-apps.md](references/test-llm-apps.md) for LLM mocking with local models, failure simulation, token rate limiting, telemetry dashboards, and MCP server testing. ### Analyze API Usage Record traffic and generate reports, specs, and governance insights. **Plugins:** `OpenApiSpecGeneratorPlugin`, `TypeSpecGeneratorPlugin`, `HttpFileGeneratorPlugin`, `HarGeneratorPlugin`, `ExecutionSummaryPlugin`, `UrlDiscoveryPlugin`, `MockGeneratorPlugin`, `GraphMinimalPermissionsPlugin`, `GraphMinimalPermissionsGuidancePlugin`, `ApiCenterOnboardingPlugin`, `ApiCenterProductionVersionPlugin` STOP — Read [references/analyze-api-usage.md](references/analyze-api-usage.md) for recording workflow, spec generation, permission analysis, shadow API detection, and reporting. ### CI/CD Integration Automate API testing in GitHub Actions, Azure Pipelines, or any CI system. STOP — Read [references/ci-cd-integration.md](references/ci-cd-integration.md) for GitHub Actions setup, Azure Pipelines config, general CI patterns, and pipeline templates. ### Configuration & Plugin Reference Set up Dev Proxy, understand plugin architecture, URL matching, proxy settings, and detached (background) mode. STOP — Read [references/configuration.md](references/configuration.md) for config file structure, plugin types and ordering, URL matching rules, proxy settings, detached mode, and process filtering. For the full plugin catalog, read [references/plugin-catalog.md](references/plugin-catalog.md). ## Configuration File Structure A quick reference. All configuration details are in [references/configuration.md](references/configuration.md). ```json { "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v4.0.0/rc.schema.json", "plugins": [ { "name": "PluginName", "enabled": true, "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll", "configSection": "pluginConfig" } ], "urlsToWatch": ["https://api.contoso.com/*"], "pluginConfig": { "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v4.0.0/pluginname.schema.json" } } ``` ### Critical Rules - Property order: `$schema` → `plugins` → `urlsToWatch` → plugin config sections → general settings - `pluginPath` is always `~appFolder/plugins/DevProxy.Plugins.dll` - Schema version must match the installed Dev Proxy version - Reporter plugins MUST be listed AFTER reporting plugins - Plugin execution order follows the config array order - File paths are relative to the config file where they are defined - Configuration hot-reloads on file save (v2.1.0+) ### Plugin Ordering 1. `RetryAfterPlugin` first (when simulating throttling) 2. `LatencyPlugin` before mock/error plugins 3. `AuthPlugin` before mock plugins 4. Response-simulating plugins (mocks, errors) 5. Reporting plugins 6. Reporters last (`MarkdownReporter`, `JsonReporter`, `PlainTextReporter`)