fix(node): standardize flush interval default

Author: dustinbyrne

.changeset/standardize-node-flush-interval.md

@@ -0,0 +1,5 @@
+---
+'posthog-node': patch
+---
+
+Fix the default Node.js event flush interval at 5 seconds.

packages/node/references/posthog-node-references-latest.json

@@ -2966,6 +2966,11 @@
         {
           "type": "number[]",
           "name": "experiment_set"
+        },
+        {
+          "description": "Whether the flag is linked to an experiment. Absent when the server does not report it.",
+          "type": "boolean",
+          "name": "has_experiment"
         }
       ],
       "path": "src/types.ts"
@@ -3244,11 +3249,6 @@
           "type": "number",
           "name": "flushAt"
         },
-        {
-          "description": "The interval in milliseconds between periodic flushes",
-          "type": "number",
-          "name": "flushInterval"
-        },
         {
           "description": "The maximum number of queued messages to be flushed as part of a single batch (must be higher than `flushAt`)",
           "type": "number",
@@ -3368,6 +3368,11 @@
           "type": "\"memory\"",
           "name": "persistence"
         },
+        {
+          "description": "The interval in milliseconds between periodic flushes",
+          "type": "number",
+          "name": "flushInterval"
+        },
         {
           "description": "The maximum number of cached messages either in memory or on the local storage (must be higher than `flushAt`)",
           "type": "number",

packages/node/src/__tests__/posthog-node.spec.ts

@@ -616,6 +616,16 @@ describe('PostHog Node.js', () => {
     })
   })
 
+  describe('flushInterval', () => {
+    it('defaults to 5000 for Node', () => {
+      const ph = new PostHog('TEST_API_KEY', {
+        host: 'http://example.com',
+      })
+
+      expect((ph as any).flushInterval).toBe(5000)
+    })
+  })
+
   describe('maxQueueSize', () => {
     it('defaults to 10000, higher than the shared core default of 1000', () => {
       const ph = new PostHog('TEST_API_KEY', {

packages/node/src/client.ts

@@ -192,6 +192,7 @@ export abstract class PostHogBackendClient extends PostHogCoreStateless implemen
       // Applied after the spread with a nullish fallback so a wrapper forwarding
       // `maxQueueSize: undefined` still gets the Node default, not the core one.
       maxQueueSize: options.maxQueueSize ?? 10000,
+      flushInterval: options.flushInterval ?? 5000,
       host: normalizeHost(options.host),
       personalApiKey: normalizePersonalApiKey(options.secretKey ?? options.personalApiKey),
     }

packages/node/src/types.ts

@@ -146,8 +146,14 @@ export type FeatureFlagBucketingIdentifier = 'distinct_id' | 'device_id' | '' |
 
 export type BeforeSendFn = (event: EventMessage | null) => EventMessage | null
 
-export type PostHogOptions = Omit<PostHogCoreOptions, 'before_send' | 'maxQueueSize'> & {
+export type PostHogOptions = Omit<PostHogCoreOptions, 'before_send' | 'flushInterval' | 'maxQueueSize'> & {
   persistence?: 'memory'
+  /**
+   * The interval in milliseconds between periodic flushes
+   *
+   * @default 5000
+   */
+  flushInterval?: number
   /**
    * The maximum number of cached messages either in memory or on the local storage (must be higher than `flushAt`)
    *