diff --git a/apps/journal/app/entry.server.tsx b/apps/journal/app/entry.server.tsx
index 6d7ae09..5db5d23 100644
--- a/apps/journal/app/entry.server.tsx
+++ b/apps/journal/app/entry.server.tsx
@@ -8,28 +8,6 @@ import type { RenderToPipeableStreamOptions } from "react-dom/server";
 import { renderToPipeableStream } from "react-dom/server";
 import { initI18nServer, detectLanguage } from "@trails-cool/i18n";
 
-const sentryEnvironment = process.env.CI ? "ci" : (process.env.NODE_ENV ?? "development");
-const sentryEnabled = process.env.NODE_ENV === "production" && !process.env.CI;
-
-Sentry.init({
-  dsn: "https://a32ffcc575d34be072e91b20f247eeee@o4509530546634752.ingest.de.sentry.io/4509530555547728",
-  release: process.env.SENTRY_RELEASE,
-  environment: sentryEnvironment,
-  tracesSampleRate: 1.0,
-  enabled: sentryEnabled,
-  sendDefaultPii: false,
-  beforeSend(event) {
-    // Drop 404s — they're expected (scanners, typos), not bugs
-    const serialized = event.extra?.__serialized__ as Record<string, unknown> | undefined;
-    if (serialized?.status === 404) return null;
-    return event;
-  },
-});
-
-if (!sentryEnabled && !process.env.CI) {
-  console.debug(`[sentry] journal SSR init inert (env=${sentryEnvironment}); would send to Sentry in production`);
-}
-
 export const streamTimeout = 5_000;
 
 export default function handleRequest(
diff --git a/apps/journal/app/lib/sentry.client.ts b/apps/journal/app/lib/sentry.client.ts
index 9c39f7b..a4f3546 100644
--- a/apps/journal/app/lib/sentry.client.ts
+++ b/apps/journal/app/lib/sentry.client.ts
@@ -1,6 +1,7 @@
 import * as Sentry from "@sentry/react";
 import { useEffect } from "react";
 import { useLocation, useNavigationType, createRoutesFromChildren, matchRoutes } from "react-router";
+import { browserSentryConfig } from "@trails-cool/sentry-config";
 
 let initialized = false;
 
@@ -8,10 +9,6 @@ export function initSentryClient() {
   if (initialized) return;
   initialized = true;
 
-  const sentryEnvironment = import.meta.env.VITE_SENTRY_ENVIRONMENT ??
-    (import.meta.env.PROD ? "production" : "development");
-  const enabled = import.meta.env.PROD && sentryEnvironment !== "ci";
-
   Sentry.init({
     dsn: "https://a32ffcc575d34be072e91b20f247eeee@o4509530546634752.ingest.de.sentry.io/4509530555547728",
     integrations: [
@@ -23,16 +20,6 @@ export function initSentryClient() {
         matchRoutes,
       }),
     ],
-    environment: sentryEnvironment,
-    tracesSampleRate: sentryEnvironment === "ci" ? 0 : 1.0,
-    enabled,
-    sendDefaultPii: false,
-    // Session Replay is not installed; document the intent explicitly.
-    replaysSessionSampleRate: 0,
-    replaysOnErrorSampleRate: 0,
+    ...browserSentryConfig("journal client", import.meta.env),
   });
-
-  if (!enabled && !import.meta.env.PROD) {
-    console.debug(`[sentry] journal client init inert (env=${sentryEnvironment}); would send to Sentry in production`);
-  }
 }
diff --git a/apps/journal/package.json b/apps/journal/package.json
index ccb61f9..0f12f8e 100644
--- a/apps/journal/package.json
+++ b/apps/journal/package.json
@@ -24,6 +24,7 @@
     "@trails-cool/gpx": "workspace:*",
     "@trails-cool/i18n": "workspace:*",
     "@trails-cool/map": "workspace:*",
+    "@trails-cool/sentry-config": "workspace:*",
     "@trails-cool/types": "workspace:*",
     "@trails-cool/ui": "workspace:*",
     "drizzle-orm": "catalog:",
diff --git a/apps/journal/server.ts b/apps/journal/server.ts
index 8495dd0..132d28e 100644
--- a/apps/journal/server.ts
+++ b/apps/journal/server.ts
@@ -1,3 +1,5 @@
+import * as Sentry from "@sentry/node";
+import { nodeSentryConfig, drop404s } from "@trails-cool/sentry-config";
 import { createRequestListener } from "@react-router/node";
 import { createServer, type IncomingMessage, type ServerResponse } from "node:http";
 import { createReadStream, statSync } from "node:fs";
@@ -7,6 +9,12 @@ import { httpRequestDuration, registry } from "./app/lib/metrics.server.ts";
 import { createBoss, startWorker } from "@trails-cool/jobs";
 import postgres from "postgres";
 
+Sentry.init({
+  dsn: "https://a32ffcc575d34be072e91b20f247eeee@o4509530546634752.ingest.de.sentry.io/4509530555547728",
+  ...nodeSentryConfig("journal server"),
+  beforeSend: drop404s,
+});
+
 const port = Number(process.env.PORT ?? 3000);
 const CLIENT_DIR = resolve(import.meta.dirname, "build", "client");
 
diff --git a/apps/mobile/lib/sentry.ts b/apps/mobile/lib/sentry.ts
index 67238bd..c21d983 100644
--- a/apps/mobile/lib/sentry.ts
+++ b/apps/mobile/lib/sentry.ts
@@ -1,22 +1,13 @@
 import * as Sentry from "@sentry/react-native";
+import { mobileSentryConfig } from "@trails-cool/sentry-config";
 
 const SENTRY_DSN = "https://af50ac7aea803216adbe21e9dd4b896b@o4509530546634752.ingest.de.sentry.io/4511209742532688";
 
 export function initSentry() {
-  const enabled = !__DEV__;
   Sentry.init({
     dsn: SENTRY_DSN,
-    tracesSampleRate: __DEV__ ? 0 : 1.0,
-    enabled,
-    sendDefaultPii: false,
-    // Session Replay is not installed; document the intent explicitly.
-    replaysSessionSampleRate: 0,
-    replaysOnErrorSampleRate: 0,
+    ...mobileSentryConfig(__DEV__),
   });
-
-  if (!enabled) {
-    console.debug("[sentry] mobile init inert in dev; would send to Sentry in production");
-  }
 }
 
 export { Sentry };
diff --git a/apps/mobile/package.json b/apps/mobile/package.json
index 8aa036c..a3b13dc 100644
--- a/apps/mobile/package.json
+++ b/apps/mobile/package.json
@@ -38,6 +38,7 @@
     "@trails-cool/gpx": "workspace:*",
     "@trails-cool/i18n": "workspace:*",
     "@trails-cool/map-core": "workspace:*",
+    "@trails-cool/sentry-config": "workspace:*",
     "@trails-cool/types": "workspace:*",
     "expo": "~55.0.15",
     "expo-constants": "~55.0.14",
diff --git a/apps/planner/app/entry.server.tsx b/apps/planner/app/entry.server.tsx
index 9220df5..5db5d23 100644
--- a/apps/planner/app/entry.server.tsx
+++ b/apps/planner/app/entry.server.tsx
@@ -1,3 +1,4 @@
+import * as Sentry from "@sentry/node";
 import { PassThrough } from "node:stream";
 import type { AppLoadContext, EntryContext } from "react-router";
 import { createReadableStreamFromReadable } from "@react-router/node";
@@ -71,6 +72,7 @@ export default function handleRequest(
           responseStatusCode = 500;
           if (shellRendered) {
             console.error(error);
+            Sentry.captureException(error);
           }
         },
       },
diff --git a/apps/planner/package.json b/apps/planner/package.json
index 38da702..50f89b5 100644
--- a/apps/planner/package.json
+++ b/apps/planner/package.json
@@ -27,6 +27,7 @@
     "@trails-cool/i18n": "workspace:*",
     "@trails-cool/map": "workspace:*",
     "@trails-cool/map-core": "workspace:*",
+    "@trails-cool/sentry-config": "workspace:*",
     "@trails-cool/types": "workspace:*",
     "@trails-cool/ui": "workspace:*",
     "codemirror": "^6.0.2",
diff --git a/apps/planner/server.ts b/apps/planner/server.ts
index 89be908..f1b072c 100644
--- a/apps/planner/server.ts
+++ b/apps/planner/server.ts
@@ -1,4 +1,5 @@
 import * as Sentry from "@sentry/node";
+import { nodeSentryConfig, drop404s } from "@trails-cool/sentry-config";
 import { logger } from "./app/lib/logger.server.ts";
 import { httpRequestDuration } from "./app/lib/metrics.server.ts";
 import { createRequestListener } from "@react-router/node";
@@ -10,26 +11,12 @@ import { createBoss, startWorker } from "@trails-cool/jobs";
 import { expireSessionsJob } from "./app/jobs/expire-sessions.ts";
 import postgres from "postgres";
 
-const sentryEnvironment = process.env.CI ? "ci" : (process.env.NODE_ENV ?? "development");
-const sentryEnabled = process.env.NODE_ENV === "production" && !process.env.CI;
-
 Sentry.init({
   dsn: "https://5215134cd78d5e6c199e29300b8425af@o4509530546634752.ingest.de.sentry.io/4511102546608208",
-  release: process.env.SENTRY_RELEASE,
-  environment: sentryEnvironment,
-  tracesSampleRate: 1.0,
-  enabled: sentryEnabled,
-  beforeSend(event) {
-    const serialized = event.extra?.__serialized__ as Record<string, unknown> | undefined;
-    if (serialized?.status === 404) return null;
-    return event;
-  },
+  ...nodeSentryConfig("planner server"),
+  beforeSend: drop404s,
 });
 
-if (!sentryEnabled && !process.env.CI) {
-  console.debug(`[sentry] planner server init inert (env=${sentryEnvironment}); would send to Sentry in production`);
-}
-
 const port = Number(process.env.PORT ?? 3001);
 const CLIENT_DIR = resolve(import.meta.dirname, "build", "client");
 
diff --git a/packages/sentry-config/package.json b/packages/sentry-config/package.json
new file mode 100644
index 0000000..1b8bdb4
--- /dev/null
+++ b/packages/sentry-config/package.json
@@ -0,0 +1,17 @@
+{
+  "name": "@trails-cool/sentry-config",
+  "version": "0.0.1",
+  "type": "module",
+  "exports": {
+    ".": "./src/index.ts"
+  },
+  "main": "./src/index.ts",
+  "types": "./src/index.ts",
+  "scripts": {
+    "lint": "eslint .",
+    "typecheck": "tsc"
+  },
+  "devDependencies": {
+    "@types/node": "catalog:"
+  }
+}
diff --git a/packages/sentry-config/src/index.ts b/packages/sentry-config/src/index.ts
new file mode 100644
index 0000000..d53202e
--- /dev/null
+++ b/packages/sentry-config/src/index.ts
@@ -0,0 +1,100 @@
+/**
+ * Shared Sentry configuration helpers for all trails.cool apps.
+ *
+ * Each app still calls its own SDK-specific `Sentry.init(...)` (they use
+ * three different SDKs: `@sentry/node`, `@sentry/react`, `@sentry/react-native`),
+ * but the common options are centralised here so privacy defaults (`sendDefaultPii: false`,
+ * replay off) and enable logic stay consistent.
+ */
+
+/**
+ * Drop 404 errors — they come from scanners/typos and aren't bugs.
+ * Pass as `beforeSend` to `Sentry.init(...)` on server-side init sites.
+ *
+ * Typed loosely on purpose: the `@sentry/node` and `@sentry/react` SDKs
+ * each have their own `ErrorEvent` / `Event` types, and we don't want this
+ * package to depend on either SDK.
+ */
+export function drop404s<E extends { extra?: Record<string, unknown> }>(event: E): E | null {
+  const serialized = event.extra?.__serialized__ as Record<string, unknown> | undefined;
+  if (serialized?.status === 404) return null;
+  return event;
+}
+
+/**
+ * Shared Sentry options for Node-side runtimes (the HTTP servers).
+ * Spread into `Sentry.init({...nodeSentryConfig("journal server"), dsn, beforeSend: drop404s, integrations})`.
+ *
+ * Logs a debug message at init time when the config is inert (local dev)
+ * so developers can see that Sentry would send in production.
+ */
+export function nodeSentryConfig(appContext: string) {
+  const environment = process.env.CI ? "ci" : (process.env.NODE_ENV ?? "development");
+  const enabled = process.env.NODE_ENV === "production" && !process.env.CI;
+
+  if (!enabled && !process.env.CI) {
+    console.debug(
+      `[sentry] ${appContext} init inert (env=${environment}); would send to Sentry in production`,
+    );
+  }
+
+  return {
+    environment,
+    enabled,
+    release: process.env.SENTRY_RELEASE,
+    tracesSampleRate: 1.0,
+    sendDefaultPii: false as const,
+  };
+}
+
+interface BrowserEnv {
+  PROD: boolean;
+  VITE_SENTRY_ENVIRONMENT?: string;
+}
+
+/**
+ * Shared Sentry options for Vite/browser runtimes.
+ * Spread into `Sentry.init({...browserSentryConfig("journal client", import.meta.env), dsn, integrations})`.
+ *
+ * Replay sample rates are explicitly 0 — replay integration is not installed,
+ * but the options document the intent and prevent accidental enablement.
+ */
+export function browserSentryConfig(appContext: string, env: BrowserEnv) {
+  const environment = env.VITE_SENTRY_ENVIRONMENT ?? (env.PROD ? "production" : "development");
+  const enabled = env.PROD && environment !== "ci";
+
+  if (!enabled && !env.PROD) {
+    console.debug(
+      `[sentry] ${appContext} init inert (env=${environment}); would send to Sentry in production`,
+    );
+  }
+
+  return {
+    environment,
+    enabled,
+    tracesSampleRate: environment === "ci" ? 0 : 1.0,
+    sendDefaultPii: false as const,
+    replaysSessionSampleRate: 0 as const,
+    replaysOnErrorSampleRate: 0 as const,
+  };
+}
+
+/**
+ * Shared Sentry options for React Native.
+ * Spread into `Sentry.init({...mobileSentryConfig(__DEV__), dsn})`.
+ */
+export function mobileSentryConfig(dev: boolean) {
+  const enabled = !dev;
+
+  if (dev) {
+    console.debug("[sentry] mobile init inert in dev; would send to Sentry in production");
+  }
+
+  return {
+    enabled,
+    tracesSampleRate: dev ? 0 : 1.0,
+    sendDefaultPii: false as const,
+    replaysSessionSampleRate: 0 as const,
+    replaysOnErrorSampleRate: 0 as const,
+  };
+}
diff --git a/packages/sentry-config/tsconfig.json b/packages/sentry-config/tsconfig.json
new file mode 100644
index 0000000..5a24989
--- /dev/null
+++ b/packages/sentry-config/tsconfig.json
@@ -0,0 +1,8 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "dist",
+    "rootDir": "src"
+  },
+  "include": ["src"]
+}
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index d2bf550..b10a7d0 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -230,6 +230,9 @@ importers:
       '@trails-cool/map':
         specifier: workspace:*
         version: link:../../packages/map
+      '@trails-cool/sentry-config':
+        specifier: workspace:*
+        version: link:../../packages/sentry-config
       '@trails-cool/types':
         specifier: workspace:*
         version: link:../../packages/types
@@ -327,6 +330,9 @@ importers:
       '@trails-cool/map-core':
         specifier: workspace:*
         version: link:../../packages/map-core
+      '@trails-cool/sentry-config':
+        specifier: workspace:*
+        version: link:../../packages/sentry-config
       '@trails-cool/types':
         specifier: workspace:*
         version: link:../../packages/types
@@ -478,6 +484,9 @@ importers:
       '@trails-cool/map-core':
         specifier: workspace:*
         version: link:../../packages/map-core
+      '@trails-cool/sentry-config':
+        specifier: workspace:*
+        version: link:../../packages/sentry-config
       '@trails-cool/types':
         specifier: workspace:*
         version: link:../../packages/types
@@ -635,6 +644,12 @@ importers:
 
   packages/map-core: {}
 
+  packages/sentry-config:
+    devDependencies:
+      '@types/node':
+        specifier: 'catalog:'
+        version: 22.19.17
+
   packages/types: {}
 
   packages/ui: {}