Social Media API for Publishing: The Developer's Guide to Unified Posting in 2026

The publishing problem looks simple

You want to post content to social media programmatically. Maybe it is an automated workflow, a feature in your SaaS product, or an AI agent that generates and distributes content. The surface-level requirement is clear: send a request, content appears on social media.

The reality is a collection of incompatible systems built by competing companies with different priorities, different developer philosophies, and different business incentives for controlling API access.

Instagram uses the Graph API with a two-step container model. TikTok uses the Content Posting API with mandatory creator info queries and a 2–4 week app audit. LinkedIn splits publishing between personal profiles and Company Pages with separate OAuth scopes. X has its own v2 API with chunked media uploads. YouTube uses a resumable upload protocol. Each has its own app review process, its own authentication quirks, and its own failure modes.

This is the social media API landscape in 2026. This guide maps it.

What “social media API integration” actually means

When developers search for a social media API, they usually mean one of two things: reading data (follower counts, analytics, mentions) or publishing content. These have very different API designs and requirements.

Publishing via social media API involves:

• Authentication — OAuth 2.0 on every platform, but with different scope requirements, token lifetimes, and refresh flows
• Request construction — Each platform has its own schema, its own required fields, and its own validation rules
• Media handling — Images and videos go through platform-specific upload protocols before they can be referenced in a post
• Rate limit management — Daily and per-minute caps that vary by platform and account tier
• Status tracking — Most platforms queue posts asynchronously, so you need to poll for completion

That is the full scope. The rest of this guide covers each component.

Platform by platform

Here is what you are actually dealing with when building social media API integrations natively:

Instagram

Instagram publishes via the Meta Graph API. Before any third-party app can publish to accounts it does not own, it must pass Meta’s app review process. Each permission requires a separate submission with a screencast showing how your app uses it.

The permissions required for publishing:

• instagram_business_basic — Basic account access
• instagram_business_content_publish — Create and publish media

After approval, posting a single image requires two API calls: create a media container, then publish it. Videos add a resumable upload step through rupload.facebook.com. Carousels require creating containers for each item, creating a parent carousel container, then publishing the parent. The review process takes 2–4 weeks per Meta’s documentation.

Instagram only supports professional accounts (Business or Creator) via API. Personal accounts cannot be published to.

TikTok

TikTok uses the Content Posting API at open.tiktokapis.com. The app audit is the most rigorous of any major platform — before your app can publish publicly, TikTok evaluates your use case, UX compliance, and content policy adherence.

Before every post, you must query the creator’s info to get their available privacy levels. TikTok requires that you show the creator’s username and avatar in your UI before posting — this is enforced during app review. Your post request must use a privacy level from the query response, or it will fail.

Until the audit completes, all posts from your app go to private visibility. The TikTok API pain article covers what the audit process actually involves.

X (Twitter)

X uses the v2 API with OAuth 2.0. Media uploads go through a separate endpoint (upload.twitter.com) using chunked multipart upload: initialize, upload chunks, finalize, then use the returned media_id in the post request.

Rate limits on X vary significantly by API access tier. The free tier has restrictions that affect automated publishing workflows. Paid tiers offer higher limits but require a subscription.

LinkedIn

LinkedIn’s publishing API splits along two dimensions: personal profiles versus Company Pages, and post types (text, image, video, article). The w_member_social scope handles personal profile posting. The w_organization_social scope handles Company Pages.

Video uploads use an asset registration flow: register the asset, get an upload URL, upload the file, then reference the asset in the post. This adds several steps compared to platforms that accept URL references directly.

Facebook

Facebook Pages use the Graph API. Publishing requires the pages_manage_posts permission and a page access token, not a user access token. Personal profiles cannot be published to via API — this is a deliberate Meta policy.

For pages with many followers, Facebook also surfaces a content policy review process. Posts can be held for review before going live.

YouTube

YouTube uses the Data API v3 with a resumable upload protocol. Uploads go through www.googleapis.com/upload/youtube/v3/videos. The flow: initiate the upload, get a session URL, upload the file in chunks, then the video processes asynchronously. A video can take minutes to process before it is publicly visible.

YouTube requires OAuth with the youtube.upload scope. Unlike most platforms, YouTube’s API access is generous — no app review for standard publishing to your own channel.

Threads

Threads uses an API modeled after Instagram’s container system. Create a container, publish the container. As a relatively new platform, the API is still evolving. Current support covers text, images, and videos. The Threads integration guide has the current endpoint details.

Pinterest

Pinterest’s API v5 supports creating pins with title, description, link, and media. Media can be uploaded via URL reference (Pinterest fetches from your URL) or through a multi-step upload flow. Pinterest requires OAuth with the pins:write scope. No formal app review is required for standard pin creation.

The authentication problem at scale

Every platform uses OAuth 2.0. The implementations differ enough to require platform-specific handling:

Token lifetimes vary:

• Instagram/Facebook: 60-day long-lived tokens, refreshable
• TikTok: 24-hour access tokens, 365-day refresh tokens
• LinkedIn: 60-day tokens, no automatic refresh (requires user re-auth)
• X: No expiry by default for user tokens (unless token rotation is enabled)
• YouTube: Short-lived access tokens with refresh tokens

Scope approval requirements:

• Meta (Instagram, Facebook): Formal app review per permission
• TikTok: Full app audit before video.publish scope can be used publicly
• LinkedIn: Most scopes available without review, but some business scopes require verification
• X: Scopes available based on API access tier
• YouTube/Pinterest: Standard OAuth without formal review

Multi-tenant complexity: If you are building a product where your users connect their social accounts, you are managing token storage, refresh schedules, and re-auth flows for every user, across every platform. When a token expires mid-workflow, you need to detect it, surface it to the user, and recover gracefully.

Media handling across platforms

Publishing a video from your system to multiple social platforms means different upload protocols for each:

For images, Instagram accepts JPEG only. X accepts JPEG, PNG, GIF, and WebP. LinkedIn accepts JPEG and PNG. Sending the wrong format returns a validation error.

Each upload protocol requires separate implementation. None of them share a common structure.

Rate limits at scale

Platform rate limits become the primary operational constraint as publishing volume increases:

At low volume, these are not operational concerns. At scale — publishing for dozens of accounts, running AI content pipelines, or automating content distribution — they require active monitoring.

The two approaches to social media API integration

Build each integration natively

You write platform-specific code for each social network. You handle OAuth per platform, build custom media upload flows, manage rate limits independently, and write error handling for each failure mode.

This approach makes sense when:

• You need to publish to one or two platforms only
• You want direct control over every aspect of the integration
• Your use case is custom enough that middleware would add friction

The trade-off is maintenance. Each platform changes its API on its own schedule. When TikTok updates a scope requirement or Meta changes its media upload protocol, you update that integration. Each new platform you add is a new full integration.

Use a unified social media API

A unified publishing API sits between your system and the individual platforms. You send one request; the unified layer handles per-platform authentication, media upload, and post submission.

curl -X POST "https://api.postproxy.dev/api/posts" \
     -H "Authorization: Bearer YOUR_API_KEY" \
     -H "Content-Type: application/json" \
     -d '{
       "post": {
         "body": "We just launched. Here is what we built."
       },
       "profiles": ["instagram", "tiktok", "twitter", "linkedin"],
       "media": ["https://example.com/video.mp4"]
     }'

That single request publishes to four platforms. Postproxy handles Instagram’s container model, TikTok’s creator info queries and audit requirements, X’s chunked upload, and LinkedIn’s asset registration.

This approach makes sense when:

• You need multi-platform publishing
• You do not want to maintain separate integrations as platform APIs evolve
• You are building a product where users connect their own social accounts
• You want to skip the app review process on each platform

Partial success and failure handling

Publishing to multiple platforms does not mean all platforms succeed simultaneously. Networks go down. Tokens expire. Media fails platform-specific validation rules.

The naive implementation collapses this into a boolean: the request succeeded or failed. But partial success is common and useful. If you publish to six platforms and one fails, you want to know:

• Which five succeeded
• Why the sixth failed
• Whether the failure is transient (worth retrying) or permanent (bad token, rejected media format)

Postproxy returns per-platform, per-account results for every publish request. This structure is what makes publishing workflows resilient rather than fragile. Each result includes the platform, the outcome, and the failure reason when applicable.

Using social media publishing in automation workflows

The most common patterns for programmatic social media publishing:

Scheduled content pipelines — A cron job or scheduled workflow pulls content from a CMS, formats it per platform, and publishes on a schedule. The scheduling guide covers this architecture.

AI content pipelines — An LLM generates platform-specific copy from a source article or brief, then a publishing API handles distribution. The AI content pipeline guide covers this end to end.

n8n workflows — n8n is the most common workflow tool for developers building social automation. Postproxy has native n8n support. The n8n tutorial walks through the workflow structure.

AI agents — Postproxy has an MCP server that lets AI agents (Claude, GPT, custom LLMs) publish directly without making raw HTTP calls. The MCP server guide covers the setup.

SaaS products — If you are building an app where users connect their social accounts and publish from within your product, the SaaS publishing guide covers the multi-tenant architecture.

What Postproxy handles as a social media management API

Postproxy is a social media publishing API built to handle the integration complexity described in this guide:

• Approved app status on Instagram, TikTok, LinkedIn, Facebook, X, YouTube, Threads, Pinterest — your app does not need to go through each platform’s review process
• OAuth and token management — Per-user token storage, refresh, and re-auth prompts
• Platform-specific media uploads — One media array in your request; Postproxy handles the format-specific upload protocol for each platform
• Rate limit monitoring — Request pacing and backoff to stay within platform limits
• Per-platform result reporting — Every publish response includes per-account outcomes, not a single pass/fail
• n8n and MCP integration — Works natively with workflow automation and AI agent tooling

The platform-specific guides go deep on what each native integration involves:

• Instagram API integration guide
• TikTok API integration guide
• LinkedIn API integration guide
• Facebook API integration guide
• X/Twitter API integration guide
• YouTube API integration guide
• Threads API integration guide
• Pinterest API integration guide

Start publishing across every platform through the Postproxy API.