Edit

Share via

Dev Proxy Toolkit diagnostics

The Dev Proxy Toolkit VS Code extension analyzes your Dev Proxy configuration files and highlights potential issues. Each diagnostic has a code that links to this page for resolution guidance.

Diagnostic codes reference

Code Severity Description
invalidSchema Warning Schema version mismatch with installed Dev Proxy
invalidConfigSection Warning Orphaned configuration section
deprecatedPluginPath Error Using old plugin DLL path
missingLanguageModel Warning Language model required but not enabled
noEnabledPlugins Warning No plugins are enabled
reporterPosition Warning Reporter plugin not at end of list
summaryWithoutReporter Warning Summary plugin without reporter
apiCenterPluginOrder Warning Incorrect plugin order for API Center
emptyUrlsToWatch Information No URLs configured to intercept
pluginConfigRequired Error/Warning Plugin requires configuration
pluginConfigMissing Error/Warning Referenced config section missing
pluginConfigNotRequired Error/Warning Unnecessary config section

invalidSchema

Severity: Warning
Quick fix available: Yes

The $schema property doesn't match the installed Dev Proxy version.

Cause

Your configuration references a different schema version than your installed Dev Proxy. This can cause validation issues or missing features.

Resolution

Update the $schema property to match your installed version. Use the quick fix (light bulb icon or Ctrl+. / Cmd+.) to update automatically.

{
  "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.0.0/rc.schema.json"
}

invalidConfigSection

Severity: Warning
Quick fix available: No

A configuration section exists but no plugin references it.

Cause

A top-level object exists that isn't used as a configSection by any plugin. This often happens after removing a plugin but forgetting to remove its configuration.

Resolution

Either remove the orphaned section or add a plugin that references it:

{
  "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.0.0/rc.schema.json",
  "plugins": [
    {
      "name": "GenericRandomErrorPlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll",
      "configSection": "genericRandomErrorPlugin"
    }
  ],
  "urlsToWatch": [
    "https://api.example.com/*"
  ],
  "genericRandomErrorPlugin": {
    "rate": 50
  }
}

deprecatedPluginPath

Severity: Error
Quick fix available: Yes

The pluginPath uses a deprecated path format.

Cause

In Dev Proxy v0.29, the plugin DLL was renamed from dev-proxy-plugins.dll to DevProxy.Plugins.dll.

Resolution

Update the pluginPath to use the new format. Use the quick fix to update automatically.

{
  "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll"
}

missingLanguageModel

Severity: Warning
Quick fix available: Yes

A plugin requires the language model but languageModel.enabled isn't true.

Cause

Plugins like LanguageModelFailurePlugin and LanguageModelRateLimitingPlugin require a language model connection.

Resolution

Add or update the languageModel configuration. Use the quick fix to add automatically.

{
  "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.0.0/rc.schema.json",
  "plugins": [
    {
      "name": "LanguageModelFailurePlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll",
      "configSection": "languageModelFailurePlugin"
    }
  ],
  "urlsToWatch": [
    "https://api.openai.com/*"
  ],
  "languageModel": {
    "enabled": true
  },
  "languageModelFailurePlugin": {
    "rate": 50
  }
}

noEnabledPlugins

Severity: Warning
Quick fix available: No

The plugins array is empty or all plugins are disabled.

Cause

Dev Proxy requires at least one enabled plugin to process requests.

Resolution

Add at least one plugin with enabled: true:

{
  "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.0.0/rc.schema.json",
  "plugins": [
    {
      "name": "MockResponsePlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll",
      "configSection": "mockResponsePlugin"
    }
  ],
  "urlsToWatch": [
    "https://api.example.com/*"
  ],
  "mockResponsePlugin": {
    "mocksFile": "mocks.json"
  }
}

reporterPosition

Severity: Warning
Quick fix available: No

A reporter plugin is placed before other nonreporter plugins.

Cause

Reporter plugins collect output from other plugins. Placing them before other plugins means they won't capture all data.

Resolution

Move reporter plugins to the end of the plugins array:

{
  "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.0.0/rc.schema.json",
  "plugins": [
    {
      "name": "MockResponsePlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll"
    },
    {
      "name": "LatencyPlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll"
    },
    {
      "name": "PlainTextReporterPlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll"
    }
  ],
  "urlsToWatch": [
    "https://api.example.com/*"
  ]
}

summaryWithoutReporter

Severity: Warning
Quick fix available: No

A summary plugin is enabled without a reporter plugin.

Cause

Plugins like ExecutionSummaryPlugin and UrlDiscoveryPlugin generate data that requires a reporter plugin to output.

Resolution

Add a reporter plugin after the summary plugin:

{
  "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.0.0/rc.schema.json",
  "plugins": [
    {
      "name": "ExecutionSummaryPlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll"
    },
    {
      "name": "PlainTextReporterPlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll"
    }
  ],
  "urlsToWatch": [
    "https://api.example.com/*"
  ]
}

apiCenterPluginOrder

Severity: Warning
Quick fix available: No

OpenApiSpecGeneratorPlugin is placed after ApiCenterOnboardingPlugin.

Cause

OpenApiSpecGeneratorPlugin must generate the OpenAPI specification before ApiCenterOnboardingPlugin can use it.

Resolution

Place OpenApiSpecGeneratorPlugin before ApiCenterOnboardingPlugin:

{
  "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.0.0/rc.schema.json",
  "plugins": [
    {
      "name": "OpenApiSpecGeneratorPlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll"
    },
    {
      "name": "ApiCenterOnboardingPlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll",
      "configSection": "apiCenterOnboardingPlugin"
    }
  ],
  "urlsToWatch": [
    "https://api.example.com/*"
  ],
  "apiCenterOnboardingPlugin": {
    "subscriptionId": "your-subscription-id",
    "resourceGroupName": "your-resource-group",
    "serviceName": "your-api-center",
    "workspaceName": "default"
  }
}

emptyUrlsToWatch

Severity: Information
Quick fix available: No

The urlsToWatch array is empty.

Cause

Dev Proxy uses urlsToWatch to determine which requests to intercept. An empty array means no requests will be processed.

Resolution

Add URL patterns to intercept:

{
  "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.0.0/rc.schema.json",
  "plugins": [
    {
      "name": "MockResponsePlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll"
    }
  ],
  "urlsToWatch": [
    "https://api.example.com/*",
    "https://graph.microsoft.com/v1.0/*"
  ]
}

pluginConfigRequired

Severity: Error (enabled plugin) / Warning (disabled plugin)
Quick fix available: No

A plugin requires a configSection but none is specified.

Cause

Some plugins require configuration to function. The plugin definition is missing the configSection property.

Resolution

Add a configSection property and create the configuration object. Use the snippet name shown in the diagnostic message.

{
  "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.0.0/rc.schema.json",
  "plugins": [
    {
      "name": "GenericRandomErrorPlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll",
      "configSection": "genericRandomErrorPlugin"
    }
  ],
  "urlsToWatch": [
    "https://api.example.com/*"
  ],
  "genericRandomErrorPlugin": {
    "errorsFile": "errors.json",
    "rate": 50
  }
}

pluginConfigMissing

Severity: Error (enabled plugin) / Warning (disabled plugin)
Quick fix available: No

A plugin references a configSection that doesn't exist.

Cause

The plugin has a configSection property but the corresponding configuration object is missing from the file.

Resolution

Add the missing configuration section. Use the snippet name shown in the diagnostic message.

{
  "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.0.0/rc.schema.json",
  "plugins": [
    {
      "name": "MockResponsePlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll",
      "configSection": "mockResponsePlugin"
    }
  ],
  "urlsToWatch": [
    "https://api.example.com/*"
  ],
  "mockResponsePlugin": {
    "mocksFile": "mocks.json"
  }
}

pluginConfigNotRequired

Severity: Error (enabled plugin) / Warning (disabled plugin)
Quick fix available: No

A plugin has a configSection but doesn't support configuration.

Cause

Not all plugins support custom configuration. Adding a configSection to a plugin that doesn't need one has no effect.

Resolution

Remove the configSection property:

{
  "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.0.0/rc.schema.json",
  "plugins": [
    {
      "name": "RetryAfterPlugin",
      "enabled": true,
      "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll"
    }
  ],
  "urlsToWatch": [
    "https://api.example.com/*"
  ]
}
  • Last updated on