Add retry mechanism for HTTP requests by EliMoshkovich · Pull Request #120 · permitio/permit-node

EliMoshkovich · 2026-02-18T16:00:35Z

Add built-in retry support with exponential backoff for transient failures
Retry on network errors and status codes: 408, 429, 500, 502, 503, 504
Respect Retry-After headers for rate limiting (429)
Default: 3 retries with exponential backoff (1s, 2s, 4s)
Add IRetryConfig interface for full configuration control
Support separate retry config for PDP calls via pdpRetry option
Enable POST retry for PDP calls (check operations are idempotent)
Add comprehensive unit tests (33 tests)
Update README with retry configuration documentation
What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
What is the current behavior? (You can also link to an open issue here)
What is the new behavior (if this is a feature change)?
Other information:

- Add built-in retry support with exponential backoff for transient failures - Retry on network errors and status codes: 408, 429, 500, 502, 503, 504 - Respect Retry-After headers for rate limiting (429) - Default: 3 retries with exponential backoff (1s, 2s, 4s) - Add IRetryConfig interface for full configuration control - Support separate retry config for PDP calls via pdpRetry option - Enable POST retry for PDP calls (check operations are idempotent) - Add comprehensive unit tests (33 tests) - Update README with retry configuration documentation Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

linear · 2026-02-18T16:00:39Z

PER-13890 Adding Retry Mechanism to node sdk

Sort imports alphabetically to satisfy eslint sort-imports rule. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Copilot

Pull request overview

Adds first-class HTTP retry support to the SDK (REST API + PDP/OPA clients), including exponential backoff, optional Retry-After handling, and user-configurable retry behavior via retry / pdpRetry options.

Changes:

Introduces retry utilities (resolveRetryConfig, backoff/jitter delay calculation, Retry-After parsing) and an Axios response interceptor to perform retries.
Wires retry configuration into Permit (API client) and Enforcer (PDP/OPA clients, with POST retries enabled for PDP/OPA).
Adds unit tests for retry utilities and documents configuration in the README.

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
yarn.lock	Lockfile adjustments from dependency resolution changes.
src/utils/retry.ts	Retry configuration/types, default condition, `Retry-After` parsing, and delay calculation utilities.
src/utils/retry-interceptor.ts	Axios response interceptor implementing retry logic + logging.
src/index.ts	Exposes retry types/constants and installs retry interceptor for REST API calls.
src/enforcement/enforcer.ts	Installs retry interceptor for PDP/OPA clients and enables POST retries for idempotent checks.
src/config.ts	Adds `retry` and `pdpRetry` options to SDK configuration.
src/tests/unit/retry.spec.ts	Adds AVA unit tests for retry utilities and basic SDK export/config checks.
README.md	Documents retry configuration and examples.

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Copilot · 2026-02-18T17:57:07Z

src/utils/retry-interceptor.ts

+  static setupInterceptor(
+    axiosInstance: AxiosInstance,
+    config: IResolvedRetryConfig,
+    logger: Logger,
+    clientName = 'HTTP',
+  ): void {
+    if (!config.enabled) {
+      return;
+    }
+
+    axiosInstance.interceptors.response.use(
+      // Success handler - pass through unchanged
+      (response) => response,
+
+      // Error handler - implement retry logic
+      async (error: AxiosError) => {
+        const originalRequest = error.config as RetryableRequestConfig | undefined;
+
+        // If no request config, cannot retry
+        if (!originalRequest) {
+          return Promise.reject(error);
+        }
+
+        // Initialize or get current retry count
+        const currentRetryCount = originalRequest[RETRY_COUNT_KEY] ?? 0;
+
+        // Check if we should retry this request
+        const method = (originalRequest.method ?? 'GET').toUpperCase();
+        const shouldRetryMethod = config.retryMethods.includes(method);
+        const shouldRetryError = config.retryCondition(error);
+        const hasRetriesLeft = currentRetryCount < config.maxRetries;
+
+        // If any condition fails, reject with original error
+        if (!shouldRetryMethod || !shouldRetryError || !hasRetriesLeft) {
+          return Promise.reject(error);
+        }
+
+        // Increment retry count for next attempt
+        originalRequest[RETRY_COUNT_KEY] = currentRetryCount + 1;
+
+        // Calculate delay before retry
+        const retryAfterHeader = error.response?.headers?.['retry-after'] as string | undefined;
+        const delay = calculateRetryDelay(currentRetryCount, config, retryAfterHeader);
+
+        // Log retry attempt
+        const statusInfo = error.response?.status ?? 'network error';
+        const url = originalRequest.url ?? 'unknown';
+        logger.warn(
+          `[${clientName}] Request failed (${statusInfo}), ` +
+            `retrying in ${Math.round(delay)}ms (attempt ${currentRetryCount + 1}/${
+              config.maxRetries
+            }): ` +
+            `${method} ${url}`,
+        );
+
+        // Wait for the calculated delay
+        await new Promise((resolve) => setTimeout(resolve, delay));
+
+        // Retry the request
+        return axiosInstance.request(originalRequest);
+      },


Retry behavior is implemented in this interceptor, but there are no unit tests that assert actual retry execution (e.g., retry count limiting, delay calculation usage, Retry-After handling, method filtering). Adding focused tests around AxiosRetryInterceptor.setupInterceptor() (with a stubbed axios instance and fake timers/Math.random) would help prevent regressions in the core feature.

Copilot · 2026-02-18T17:57:08Z

src/enforcement/enforcer.ts

+      // For PDP calls, enable POST retry since check operations are idempotent
+      const pdpRetryWithPost = {
+        ...pdpRetryConfig,
+        retryMethods: [...pdpRetryConfig.retryMethods, 'POST'],


pdpRetryWithPost appends 'POST' to retryMethods without deduplicating. If the user already includes POST, this can create duplicates. Consider ensuring uniqueness (e.g., via new Set(...)) when constructing the PDP method list.

Suggested change

// For PDP calls, enable POST retry since check operations are idempotent

const pdpRetryWithPost = {

...pdpRetryConfig,

retryMethods: [...pdpRetryConfig.retryMethods, 'POST'],

// For PDP calls, ensure POST is retried (check operations are idempotent), without duplicates

const pdpRetryWithPost = {

...pdpRetryConfig,

retryMethods: [...new Set([...pdpRetryConfig.retryMethods, 'POST'])],

Copilot · 2026-02-18T17:57:08Z

src/tests/unit/retry.spec.ts

+  // Use a future date
+  const futureDate = new Date(Date.now() + 10000);
+  const httpDate = futureDate.toUTCString();
+  const result = parseRetryAfter(httpDate);
+
+  t.truthy(result);
+  // Should be approximately 10 seconds (10000ms), with some tolerance
+  t.true(result! > 9000 && result! < 11000);
+});
+
+test('parseRetryAfter returns 0 for past HTTP-date', (t) => {
+  const pastDate = new Date(Date.now() - 10000);
+  const httpDate = pastDate.toUTCString();
+  const result = parseRetryAfter(httpDate);
+
+  t.is(result, 0);


This test can be flaky because it depends on wall-clock timing (it asserts the parsed delay is within a 2s window). Consider stubbing Date.now() (or passing a "now" value into parseRetryAfter) so the test uses fixed timestamps and remains deterministic across slow CI environments.

Suggested change

// Use a future date

const futureDate = new Date(Date.now() + 10000);

const httpDate = futureDate.toUTCString();

const result = parseRetryAfter(httpDate);

t.truthy(result);

// Should be approximately 10 seconds (10000ms), with some tolerance

t.true(result! > 9000 && result! < 11000);

});

test('parseRetryAfter returns 0 for past HTTP-date', (t) => {

const pastDate = new Date(Date.now() - 10000);

const httpDate = pastDate.toUTCString();

const result = parseRetryAfter(httpDate);

t.is(result, 0);

const originalNow = Date.now;

try {

const fixedNow = 1700000000000; // arbitrary fixed timestamp

(Date as any).now = () => fixedNow;

const futureDate = new Date(fixedNow + 10000);

const httpDate = futureDate.toUTCString();

const result = parseRetryAfter(httpDate);

t.is(result, 10000);

} finally {

(Date as any).now = originalNow;

}

});

test('parseRetryAfter returns 0 for past HTTP-date', (t) => {

const originalNow = Date.now;

try {

const fixedNow = 1700000000000; // arbitrary fixed timestamp

(Date as any).now = () => fixedNow;

const pastDate = new Date(fixedNow - 10000);

const httpDate = pastDate.toUTCString();

const result = parseRetryAfter(httpDate);

t.is(result, 0);

} finally {

(Date as any).now = originalNow;

}

Copilot · 2026-02-18T17:57:08Z

README.md

+```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 },
+});


The README example redeclares const permit multiple times within the same code block, which won't type-check if copy/pasted. Consider using different variable names (e.g., permitDefault, permitCustom, ...) or splitting into separate code blocks.

Copilot · 2026-02-18T17:57:09Z

src/utils/retry.ts

+  // Try parsing as seconds (integer)
+  const seconds = parseInt(value, 10);
+  if (!isNaN(seconds)) {
+    return seconds * 1000;


parseRetryAfter() uses parseInt() which will accept partially-numeric strings (e.g. "5abc" -> 5). Per the Retry-After spec, delta-seconds should be digits only; consider validating with a digits-only regex (or Number() + string check) before converting, otherwise invalid headers may be treated as valid delays.

Suggested change

// Try parsing as seconds (integer)

const seconds = parseInt(value, 10);

if (!isNaN(seconds)) {

return seconds * 1000;

// Try parsing as seconds (integer). Per spec, this must be digits only.

const trimmed = value.trim();

if (/^\d+$/.test(trimmed)) {

const seconds = Number(trimmed);

if (!Number.isNaN(seconds)) {

return seconds * 1000;

}

Copilot · 2026-02-18T17:57:09Z

src/utils/retry.ts

+  // If undefined or empty, use defaults
+  if (!userConfig) {
+    return DEFAULT_RETRY_CONFIG;
+  }


resolveRetryConfig(undefined) returns the DEFAULT_RETRY_CONFIG object by reference. Since DEFAULT_RETRY_CONFIG is exported and mutable, consumers could mutate it and unintentionally affect retry behavior globally. Consider returning a shallow copy (and cloning retryMethods) or freezing the default config to prevent external mutation.

Copilot · 2026-02-18T17:57:09Z

src/utils/retry.ts

+  // Merge user config with defaults
+  return {
+    enabled: userConfig.enabled ?? DEFAULT_RETRY_CONFIG.enabled,
+    maxRetries: userConfig.maxRetries ?? DEFAULT_RETRY_CONFIG.maxRetries,
+    retryDelay: userConfig.retryDelay ?? DEFAULT_RETRY_CONFIG.retryDelay,
+    backoffMultiplier: userConfig.backoffMultiplier ?? DEFAULT_RETRY_CONFIG.backoffMultiplier,
+    maxDelay: userConfig.maxDelay ?? DEFAULT_RETRY_CONFIG.maxDelay,
+    retryCondition: userConfig.retryCondition ?? DEFAULT_RETRY_CONFIG.retryCondition,
+    respectRetryAfter: userConfig.respectRetryAfter ?? DEFAULT_RETRY_CONFIG.respectRetryAfter,
+    retryMethods: userConfig.retryMethods ?? DEFAULT_RETRY_CONFIG.retryMethods,
+  };


AxiosRetryInterceptor uppercases the request method, but resolveRetryConfig() passes through retryMethods as provided. If a user supplies lowercase methods (common in axios configs), retries will never trigger. Consider normalizing retryMethods to uppercase when resolving config (or normalizing both sides in the interceptor).

Copilot · 2026-02-18T17:57:09Z

src/utils/retry-interceptor.ts

+import { calculateRetryDelay, IResolvedRetryConfig } from './retry';
+
+// Symbols to track retry state on request config (avoids polluting the config object)
+const RETRY_COUNT_KEY = '__permitRetryCount';


Comment says "Symbols to track retry state" but the implementation uses a string key ('__permitRetryCount'). Either switch to a Symbol to avoid any chance of key collision or update the comment to reflect the actual approach.

Suggested change

const RETRY_COUNT_KEY = '__permitRetryCount';

const RETRY_COUNT_KEY = Symbol('permitRetryCount');

Fix import sort order in retry tests

ef4842d

Sort imports alphabetically to satisfy eslint sort-imports rule. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

EliMoshkovich requested review from Copilot and zeevmoney February 18, 2026 17:52

Copilot started reviewing on behalf of EliMoshkovich February 18, 2026 17:53 View session

Copilot AI reviewed Feb 18, 2026

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Add retry mechanism for HTTP requests#120

Add retry mechanism for HTTP requests#120
EliMoshkovich wants to merge 2 commits intomainfrom
PER-13890-adding-node-sdk

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	const RETRY_COUNT_KEY = '__permitRetryCount';
	const RETRY_COUNT_KEY = Symbol('permitRetryCount');

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EliMoshkovich commented Feb 18, 2026

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