Developer Platform
Run your socials from code
A REST API, MCP server, CLI, and webhooks - build any social media automation across 10 platforms without writing a line of front-end code.
Connect · What you can build · Webhooks · Get started
Sydium puts the core of the app behind a clean REST API: publish and schedule posts, manage accounts, pull analytics, generate AI captions, and react to events. Then go a step further - connect an AI agent like Claude or ChatGPT (or any MCP-compatible client) via the MCP server and issue natural-language instructions directly to your social accounts.
“Connect your AI agent to your social accounts. Let it write, schedule, and publish - you stay in charge.”
Dispatch I
Three ways to connect
Pick the interface that fits your workflow - REST, CLI, or MCP. All three share the same auth model and the same capabilities.
REST API
Standard HTTP on api.sydium.com
Every app action - publish, schedule, analyze, generate - is a single authenticated request. Bearer tokens scoped to the platforms and operations you choose. JSON in, JSON out.
CLI
npx @sydium/cli from your terminal
Automate from shell scripts, CI pipelines, or any tool that runs a command. List connected accounts, publish drafts, pull weekly analytics - without opening a browser.
MCP Server
Natural-language control from your AI agent
Add the Sydium MCP endpoint to your agent and authorize it with one click in your browser - no API keys to paste, no tokens to leak. Your agent can then list your accounts, draft captions, schedule posts, and pull performance data, all in plain English.
Dispatch II
What you can build
The API covers the core of what Sydium does - publishing, scheduling, analytics, AI generation, and live platform capabilities.
Publish & schedule
POST /v1/posts
Send text, images, or video to one or more platforms in a single request. Schedule with an ISO 8601 timestamp. The API handles format normalization per platform so your payload never hits a format error.
Analytics
GET /v1/analytics
Reach, impressions, engagement rate, follower growth. Filter by platform and date range. Feed the data into dashboards, Slack digests, or automated weekly reports.
AI generation
POST /v1/generate
Sydium has already learned the account voice from past content. Send a topic or image; get back a caption tuned to the platform character limit and the account voice profile.
Platform capabilities
GET /v1/platforms
Every platform has different character limits, aspect ratios, and feature sets. The capabilities endpoint returns the exact constraints in real time - a genuine differentiator for automation builders.
Dispatch III
React to events
Stop polling. Register an HTTPS endpoint and Sydium delivers signed event payloads the moment something happens.
post.published
Fires when a post goes live on the platform. Includes the platform post ID and permalink.
post.failed
Fires when a publish attempt fails. Includes the error code and a human-readable reason so you can react without manual monitoring.
Signed deliveries
Every webhook carries an X-Sydium-Signature header - an HMAC-SHA256 of the payload signed with your webhook secret. Verify it before processing to guarantee authenticity.
Start building in minutes
The full API reference is at docs.sydium.com. Grab an API key from your account settings and make your first request.
Read the docs