diff --git a/.yarn/cache/@mittwald-api-client-commons-npm-4.430.0-70bb458241-3e3a563c3a.zip b/.yarn/cache/@mittwald-api-client-commons-npm-4.436.0-9b050290d3-4996448145.zip
similarity index 88%
rename from .yarn/cache/@mittwald-api-client-commons-npm-4.430.0-70bb458241-3e3a563c3a.zip
rename to .yarn/cache/@mittwald-api-client-commons-npm-4.436.0-9b050290d3-4996448145.zip
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diff --git a/.yarn/cache/@mittwald-api-client-npm-4.430.0-41134e9036-3645b95caa.zip b/.yarn/cache/@mittwald-api-client-npm-4.430.0-41134e9036-3645b95caa.zip
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diff --git a/.yarn/cache/@mittwald-api-client-npm-4.436.0-d8ff25010b-5cffe9f29c.zip b/.yarn/cache/@mittwald-api-client-npm-4.436.0-d8ff25010b-5cffe9f29c.zip
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diff --git a/CLAUDE.md b/CLAUDE.md
index 4405f11f4..04dbffa81 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -82,6 +82,19 @@ providers:
 - Uses `@mittwald/api-client` for API communication
 - Automatic retry logic and consistency handling
 - Authentication via API tokens (file, environment, or flag)
+- **Only ever call the API through the methods that `@mittwald/api-client`
+  generates.** Never hand-roll API calls (for example via `apiClient.axios`,
+  `fetch` or a hand-written operation descriptor), and never re-implement an
+  operation the client no longer exposes.
+- When a client method disappears after an `@mittwald/api-client` bump, the
+  underlying operation was deprecated in the OpenAPI spec and dropped from code
+  generation. Do not work around this — find the successor operation the spec
+  points to and use it. The replacement is frequently a property on a regular
+  resource endpoint rather than a like-for-like operation. For instance,
+  `app-link-database` and `app-replace-database` were superseded by the
+  `databases` property of `app.patchAppinstallation`. Searching the spec for
+  paths containing the resource name will miss such successors; check the
+  resource's own `PATCH` endpoint too.
 
 ## Coding hints
 
diff --git a/src/commands/app/database/link.tsx b/src/commands/app/database/link.tsx
index 927c623cf..4303516a1 100644
--- a/src/commands/app/database/link.tsx
+++ b/src/commands/app/database/link.tsx
@@ -71,13 +71,16 @@ export default class Link extends ExecRenderBaseCommand<typeof Link, void> {
     });
 
     await process.runStep("linking database", async () => {
-      const response = await this.apiClient.app.linkDatabase({
+      const response = await this.apiClient.app.patchAppinstallation({
         appInstallationId,
         data: {
-          databaseId,
-          purpose: purpose as "primary" | "cache" | "custom",
-          databaseUserIds: {
-            admin: adminUserId,
+          databases: {
+            [databaseId]: {
+              purpose: purpose as "primary" | "cache" | "custom",
+              databaseUserIds: {
+                admin: adminUserId,
+              },
+            },
           },
         },
       });
diff --git a/src/commands/app/database/replace.tsx b/src/commands/app/database/replace.tsx
index a77e02683..2c9b2e148 100644
--- a/src/commands/app/database/replace.tsx
+++ b/src/commands/app/database/replace.tsx
@@ -87,13 +87,16 @@ export default class Replace extends ExecRenderBaseCommand<
     );
 
     await process.runStep("replacing database", async () => {
-      const response = await this.apiClient.app.replaceDatabase({
+      const response = await this.apiClient.app.patchAppinstallation({
         appInstallationId,
         data: {
-          oldDatabaseId,
-          newDatabaseId,
-          databaseUserIds: {
-            admin: adminUserId,
+          databases: {
+            [newDatabaseId]: {
+              replacesDatabaseId: oldDatabaseId,
+              databaseUserIds: {
+                admin: adminUserId,
+              },
+            },
           },
         },
       });
diff --git a/yarn.lock b/yarn.lock
index dd7e76265..cd6b046ff 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1870,9 +1870,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@mittwald/api-client-commons@npm:^4.430.0":
-  version: 4.430.0
-  resolution: "@mittwald/api-client-commons@npm:4.430.0"
+"@mittwald/api-client-commons@npm:^4.436.0":
+  version: 4.436.0
+  resolution: "@mittwald/api-client-commons@npm:4.436.0"
   dependencies:
     "@types/parse-path": ^7.0.3
     axios: ^1.15.2
@@ -1886,22 +1886,22 @@ __metadata:
       optional: true
     "@mittwald/react-use-promise":
       optional: true
-  checksum: 3e3a563c3a4de7e99ed0d3950280b1a5e7bcb878365dafbf2361c9db1caddabd7d1751be57269daa47170b6c171d560faee9666b9c8c79946fb4c76da5d7a16f
+  checksum: 499644814517aa12fc2d13ef87de6433236da0057b2aeebb3b60ca66b0ce347989fba39aa971085fd4ec7502f9ff455dd214fda312e0770c82370b1ef1250b98
   languageName: node
   linkType: hard
 
 "@mittwald/api-client@npm:^4.400.0":
-  version: 4.430.0
-  resolution: "@mittwald/api-client@npm:4.430.0"
+  version: 4.436.0
+  resolution: "@mittwald/api-client@npm:4.436.0"
   dependencies:
-    "@mittwald/api-client-commons": ^4.430.0
+    "@mittwald/api-client-commons": ^4.436.0
     browser-or-node: ^3.0.0
   peerDependencies:
     "@mittwald/react-use-promise": ^2.6.0
   peerDependenciesMeta:
     "@mittwald/react-use-promise":
       optional: true
-  checksum: 3645b95caad1129d4961b779dc0c99f687143f9db249d2a96768a1fae1632a50625f7cb62bf3fca4797f1d897e6f52915c66cfa9473e1f0a31a1e789f9bf78bc
+  checksum: 5cffe9f29c6899115ae92750aa7d1d85785ce82030068129364e0484893fd0f8fd612b8f8c20eda653f924f9569df1a26872d80cb054ad22d214111bc4358c00
   languageName: node
   linkType: hard