diff --git a/modules/rsocials/lib/postiz-client.ts b/modules/rsocials/lib/postiz-client.ts
index 4d83907c..18b6b22f 100644
--- a/modules/rsocials/lib/postiz-client.ts
+++ b/modules/rsocials/lib/postiz-client.ts
@@ -60,7 +60,7 @@ export async function getIntegrations(config: PostizConfig) {
 /** POST /public/v1/posts — create a single post (draft, schedule, or now).
  *
  * Postiz expects a nested shape:
- *   { type, date, shortLink, tags, posts: [{ integration: {id}, value: [{content}], settings: {__type} }] }
+ *   { type, date, shortLink, tags, posts: [{ integration: {id}, value: [{content}], settings: {__type, ...} }] }
  *
  * Callers pass integrations as {id, identifier} tuples; identifier populates
  * settings.__type which Postiz uses to route to the correct provider handler.
@@ -70,6 +70,32 @@ export interface PostizIntegrationRef {
 	identifier: string; // e.g. 'x', 'linkedin', 'bluesky'
 }
 
+// Platform-specific settings Postiz validates on POST /posts. Keys that are
+// required-non-empty for each provider live here. We merge defaults when the
+// caller doesn't supply overrides.
+function defaultSettingsFor(identifier: string): Record<string, unknown> {
+	const base: Record<string, unknown> = { __type: identifier };
+	switch (identifier) {
+		case 'x':
+			base.who_can_reply_post = 'everyone';
+			break;
+		case 'linkedin':
+			base.post_to_company = false;
+			break;
+		case 'instagram':
+			base.post_type = 'post';
+			break;
+		case 'youtube':
+			base.type = 'public';
+			base.title = '';
+			base.category = '22';
+			break;
+		// Others (bluesky, threads, mastodon, reddit, ...) don't require settings
+		// beyond __type as of Postiz 5.x.
+	}
+	return base;
+}
+
 export async function createPost(
 	config: PostizConfig,
 	payload: {
@@ -89,7 +115,7 @@ export async function createPost(
 			integration: { id: integ.id },
 			value: [{ content: payload.content, image: [] as unknown[] }],
 			...(payload.group ? { group: payload.group } : {}),
-			settings: { __type: integ.identifier },
+			settings: defaultSettingsFor(integ.identifier),
 		})),
 	};
 	const res = await postizFetch(config, "/public/v1/posts", {
@@ -153,7 +179,7 @@ export async function createThread(
 		posts: opts.integrations.map(integ => ({
 			integration: { id: integ.id },
 			value: tweets.map(t => ({ content: t, image: [] as unknown[] })),
-			settings: { __type: integ.identifier },
+			settings: defaultSettingsFor(integ.identifier),
 		})),
 	};
 	const res = await postizFetch(config, "/public/v1/posts", {