One REST API to publish content across 21 platforms. Post text, images, videos, and more with a single endpoint.
No credit card required · Full API access
Features
Publish to Twitter/X, Instagram, LinkedIn, TikTok, Bluesky, Mastodon, and 11 more platforms from a single API call. No need to learn each platform's quirks.
Schedule posts for any future date and time. RelayAPI handles timezone conversion, queue management, and guaranteed delivery at the exact moment you specify.
Create multi-part threads on Twitter/X and Bluesky, or carousel posts on Instagram and LinkedIn. Pass an array of content blocks and we handle the rest.
Automatically adapt content for each platform's constraints — character limits, hashtag placement, mention formatting, and link card generation.
Save posts as drafts, preview how they'll appear on each platform, and publish when ready. Collaborate with your team before anything goes live.
Track every post through its lifecycle — queued, publishing, published, or failed — with detailed per-platform status and direct links to live posts.
Receive real-time webhooks when posts are successfully delivered or fail on any platform. Build reactive workflows without polling for status.
Transient platform failures are automatically retried with exponential backoff. Configure retry policies per post or rely on sensible defaults.
Sign up and generate your credentials in seconds.
Link platforms via OAuth with our guided setup flow.
Use the API to publish, manage, and track content everywhere.
Each social platform has its own auth flow, rate limits, and content rules. RelayAPI abstracts all 17 behind a single REST endpoint so you can focus on your product, not platform quirks.
Built on Cloudflare's global edge network with 99.9% uptime. Automatic retries, dead-letter queues, and detailed delivery reports mean your content reaches every platform — every time.
Interactive API docs, TypeScript and Python SDKs, copy-paste code examples, and a responsive support team. Everything you need to integrate quickly and maintain confidently.
Quick start
curl -X POST https:"color:#857f73">//api.relayapi.dev/v1/posts \
-H "Authorization: Bearer rlay_live_xxxxxxxx" \
-H "Content-Type: application/json" \
-d '{
"content": "Excited to announce our new product launch! Check it out at https:">//example.com",
"platforms": ["twitter", "linkedin", "bluesky"],
"media": [
{ "url": "https:">//cdn.example.com/launch-banner.png", "alt_text": "Product launch banner" }
],
"scheduled_for": "2026-04-01T14:00:00Z"
}'Free plans allow 100 posts per day across all platforms. Pro plans support up to 5,000 posts per day, and Enterprise plans offer custom limits. Per-platform rate limits are handled automatically — if a platform throttles a request, RelayAPI queues it and retries within the platform's allowed window.
RelayAPI currently supports 21 platforms across social, messaging, and newsletter categories: Instagram, Facebook, LinkedIn, TikTok, YouTube, Bluesky, Mastodon, Threads, Pinterest, Reddit, Discord, Telegram, WhatsApp Business, Google Business Profile, Snapchat, X/Twitter, SMS, Beehiiv, ConvertKit, Mailchimp, and Listmonk. New platforms are added regularly.
Posts can be scheduled up to 90 days in advance. Scheduled posts are stored durably and processed by a dedicated scheduler that guarantees delivery within 30 seconds of the target time. You can update or cancel a scheduled post at any time before it publishes.
Images: JPEG, PNG, WebP, GIF (up to 20 MB). Videos: MP4, MOV, WebM (up to 500 MB). RelayAPI automatically converts and resizes media to meet each platform's requirements, so you only need to upload once.
Each platform in a multi-platform post is treated independently. If a post fails on Twitter but succeeds on LinkedIn, you'll see per-platform status in the response. Failed deliveries are retried up to 3 times with exponential backoff. Permanent failures (e.g., invalid content) return detailed error codes and messages you can surface to your users.
Yes. Use the platform_overrides field to customize content per platform — for example, a longer caption on LinkedIn, different hashtags on Instagram, or a shorter version for Twitter's character limit. The base content field serves as the default for any platform without an override.
Get your API key and publish across 21 platforms in minutes.