Add retry mechanism for HTTP requests

README.md

@@ -17,6 +17,47 @@ npm install permitio
 3. Execute `yarn docs ; git add docs/ ; git commit -m "update tsdoc"` to update the auto generated docs
 4. Execute `yarn publish --access public`
 
+## Retry Configuration
+
+The SDK includes built-in retry support for transient failures. By default, retries are **enabled** with the following settings:
+
+- **3 retry attempts** with exponential backoff
+- Retries on network errors and status codes: `408`, `429`, `500`, `502`, `503`, `504`
+- Respects `Retry-After` headers for rate limiting (429)
+
+### Customizing Retry Behavior
+
+```typescript
+import { Permit } from 'permitio';
+
+// Use defaults (retry enabled)
+const permit = new Permit({ token: 'your-api-key' });
+
+// Custom retry configuration
+const permit = new Permit({
+  token: 'your-api-key',
+  retry: {
+    maxRetries: 5,
+    retryDelay: 500,        // Initial delay in ms
+    backoffMultiplier: 2,   // Exponential backoff multiplier
+    maxDelay: 30000,        // Maximum delay cap
+  },
+});
+
+// Disable retry entirely
+const permit = new Permit({
+  token: 'your-api-key',
+  retry: false,
+});
+
+// Different config for PDP vs REST API
+const permit = new Permit({
+  token: 'your-api-key',
+  retry: { maxRetries: 3 },
+  pdpRetry: { maxRetries: 5 },
+});
+```
+
 ## Documentation
 
 [Read the documentation at Permit.io website](https://docs.permit.io/sdk/nodejs/quickstart-nodejs#add-the-sdk-to-your-js-code)

src/config.ts

@@ -2,6 +2,7 @@ import globalAxios, { AxiosInstance } from 'axios';
 import _ from 'lodash';
 
 import { ApiContext } from './api/context';
+import { IRetryConfig } from './utils/retry';
 import { RecursivePartial } from './utils/types';
 
 export type FactsSyncTimeoutPolicy = 'ignore' | 'fail';
@@ -110,6 +111,24 @@ export interface IPermitConfig {
    * @see https://axios-http.com/docs/req_config
    */
   opaAxiosInstance?: AxiosInstance;
+
+  /**
+   * Configuration for automatic retry of failed requests.
+   * Set to false to disable retries entirely.
+   * Defaults to enabled with sensible defaults (3 retries, exponential backoff).
+   *
+   * @see {@link IRetryConfig}
+   */
+  retry?: IRetryConfig | false;
+
+  /**
+   * Optional separate retry configuration for PDP (enforcement) calls.
+   * If not provided, uses the main `retry` configuration.
+   * Set to false to disable retries for PDP calls only.
+   *
+   * @see {@link IRetryConfig}
+   */
+  pdpRetry?: IRetryConfig | false;
 }
 
 /**

src/enforcement/enforcer.ts

@@ -5,6 +5,8 @@ import URL from 'url-parse';
 import { IPermitConfig } from '../config';
 import { CheckConfig, Context, ContextStore } from '../utils/context';
 import { AxiosLoggingInterceptor } from '../utils/http-logger';
+import { resolveRetryConfig } from '../utils/retry';
+import { AxiosRetryInterceptor } from '../utils/retry-interceptor';
 
 import {
   AllTenantsResponse,
@@ -163,6 +165,20 @@ export class Enforcer implements IEnforcer {
     }
     this.logger = logger;
     AxiosLoggingInterceptor.setupInterceptor(this.client, this.logger);
+
+    // Setup retry interceptors for PDP clients
+    // Use pdpRetry config if provided, otherwise fall back to main retry config
+    const pdpRetryConfig = resolveRetryConfig(config.pdpRetry ?? config.retry);
+    if (pdpRetryConfig.enabled) {
+      // For PDP calls, enable POST retry since check operations are idempotent
+      const pdpRetryWithPost = {
+        ...pdpRetryConfig,
+        retryMethods: [...pdpRetryConfig.retryMethods, 'POST'],
+      };
+      AxiosRetryInterceptor.setupInterceptor(this.client, pdpRetryWithPost, this.logger, 'PDP');
+      AxiosRetryInterceptor.setupInterceptor(this.opaClient, pdpRetryWithPost, this.logger, 'OPA');
+    }
+
     this.contextStore = new ContextStore();
   }
 

src/index.ts

@@ -15,6 +15,8 @@ import {
 import { LoggerFactory } from './logger';
 import { CheckConfig, Context } from './utils/context';
 import { AxiosLoggingInterceptor } from './utils/http-logger';
+import { resolveRetryConfig } from './utils/retry';
+import { AxiosRetryInterceptor } from './utils/retry-interceptor';
 import { RecursivePartial } from './utils/types';
 
 // exported interfaces
@@ -25,6 +27,12 @@ export { PermitConnectionError, PermitError, PermitPDPStatusError } from './enfo
 export { Context, ContextTransform } from './utils/context';
 export { ApiContext, PermitContextError, ApiKeyLevel } from './api/context';
 export { PermitApiError } from './api/base';
+export {
+  IRetryConfig,
+  RetryConditionFn,
+  RETRYABLE_STATUS_CODES,
+  NON_RETRYABLE_STATUS_CODES,
+} from './utils/retry';
 
 export interface IPermitClient extends IEnforcer {
   /**
@@ -140,6 +148,17 @@ export class Permit implements IPermitClient {
     this.logger = LoggerFactory.createLogger(this.config);
     AxiosLoggingInterceptor.setupInterceptor(this.config.axiosInstance, this.logger);
 
+    // Setup retry interceptor for REST API calls
+    const resolvedRetryConfig = resolveRetryConfig(this.config.retry);
+    if (resolvedRetryConfig.enabled) {
+      AxiosRetryInterceptor.setupInterceptor(
+        this.config.axiosInstance,
+        resolvedRetryConfig,
+        this.logger,
+        'API',
+      );
+    }
+
     this.api = new ApiClient(this.config, this.logger);
 
     this.enforcer = new Enforcer(this.config, this.logger);