For most developers adding social features to a product, a unified API is the right call, and Zernio is the most complete one: 16 channels through one REST API, with posting, comments, DMs, analytics and ads on 8 ad networks behind the same key. It's built for SaaS products where thousands of end users connect their own accounts, and for AI agents that need the same surface through MCP.
Go native only when one platform is your whole product and you need a feature no unified layer exposes.
→ Start building with Zernio's social media API: 16 channels, one API key, first 2 accounts free.
Which social media API should you use?
Match the API to what you're building. Every pick below is explained in its own section further down.
| What you're building | Pick | Why |
|---|---|---|
| A SaaS product where users connect 5+ networks | Zernio | OAuth-as-a-service with a white-label connect flow, and per-account pricing that drops to $1 an account past 100. Readdy runs 2,349 customer accounts on it. |
| An agency or white-label client dashboard | Zernio | Headless connect, so clients never see a Zernio screen. ACT.agency runs 8 white-label client workspaces on it. |
| An AI agent that publishes, replies and boosts | Zernio | Hosted MCP server, a CLI with JSON output, and ads in the same API, so the agent can close the publish, analyze, boost loop. |
| Social plus WhatsApp and DMs in one inbox | Zernio | One inbox API across social DMs, comments, WhatsApp, Telegram and iMessage. |
| Organic and paid social in one integration | Zernio | Boost posts and run campaigns on Meta, Google, TikTok, LinkedIn, Pinterest, X, OpenAI and Reddit through /v1/ads. |
| Low-volume posting, no engagement features | Post for Me or Outstand | Post-metered plans from $10 and $19 a month with unlimited accounts. |
| A self-hosted, open-source stack | Postiz | Open source, with a hosted option if you change your mind. |
| Automations for channels you already manage in Buffer | Buffer API | Same account, same queue, no new vendor. |
| LinkedIn inbox and outreach tooling | Unipile | Messaging-first, built around LinkedIn. |
| Listening to mentions across the web | Octolens | Read-only mentions API with sentiment. |
| Creator audience and income data | Phyllo | Creator audience, engagement and income data. |
| One platform, its deepest features | That platform's native API | Full access, at the cost of app review and maintenance. |
How we evaluated these APIs
We compared every API on the same five questions, using each vendor's own pricing page and docs, checked in October 2026:
- Coverage: which networks it reaches, and which actions (posting, comments, DMs, analytics, ads) work on each.
- Auth model: whether your end users can connect their own accounts without you registering a developer app per platform.
- Limits: documented rate limits and posting caps.
- Cost at scale: list price at 10, 100 and 1,000 connected accounts.
- Agent tooling: MCP server, CLI and SDKs.
Zernio wrote this guide, so treat our own entry with the same skepticism as the rest. To make that easy, Zernio's uptime, latency and failed requests are public as live production data at zernio.com/open. Competitor prices are list prices from their sites and can change. If something here is out of date, tell us and we'll fix it.
Table of contents
- Which social media API should you use?
- How we evaluated these APIs
- What is a social media API?
- Unified vs. native social media APIs: which do you need?
- When does a unified social media API make sense?
- When do native platform APIs make sense?
- Best unified social media APIs for developers
- What can each unified social media API actually do?
- What does a social media API cost at scale?
- How does authentication work across these APIs?
- Best native platform APIs for developers
- Social media APIs for AI agents and MCP
- FAQ
What is a social media API?
A social media API is a programmatic interface that lets your code interact with a social platform: creating posts, reading comments, sending DMs, pulling analytics, managing accounts, and more.
There are two distinct categories. Native platform APIs are published directly by the platforms (Meta, X, TikTok, LinkedIn). They give you the deepest access to platform-specific features, but each one has its own authentication flow, rate limits, permissions system, and breaking-change cadence.
Unified social media APIs (like Zernio, Ayrshare, Upload-Post) sit on top of all those native APIs and expose one consistent REST endpoint. You call one API; the unified layer handles format normalization, auth, retries, and media transcoding per platform.
The right choice depends entirely on what you're building. This guide covers both.
Unified vs. native social media APIs: which do you need?
The decision comes down to two things: how many platforms you need, and whether you need platform-specific advanced features.
| Factor | Unified API | Native API |
|---|---|---|
| Integration time | Hours | Months per platform |
| Platforms covered | 9 to 30, depending on the vendor | 1 per integration |
| Auth complexity | Single Bearer token | OAuth per platform |
| Maintenance burden | On the API vendor | On your team |
| Rate limit management | Handled for you | Managed by you |
| Best for | Multi-platform tools, SaaS, agents | Ads, deep analytics, platform-native features |
When does a unified social media API make sense?
You're posting to more than two platforms. The integration cost of native APIs compounds fast. Instagram's app review alone can take weeks. Add LinkedIn, TikTok, X, YouTube and Reddit and you're months in before writing a single feature for your actual product.
You're building a SaaS where end users connect their own social accounts. Each user needs their own OAuth tokens per platform. A unified API runs that as a service: users authenticate through one connect flow, and the API manages platform tokens, refresh cycles and expiry for you.
You're building an AI agent that publishes content. Agents need predictable tools. Zernio's hosted MCP server gives any MCP client the posting, scheduling, inbox, analytics and ads surface across 16 channels, with no custom wrappers. More in the AI agents section.
You need the full social layer, not just posting. Most teams underestimate what comes after the first post: comments, DMs, analytics and webhooks are separate API surfaces on every platform. A unified API bundles them.
You want infrastructure costs you can forecast. Native APIs are free to call but expensive to run: app reviews, quota extensions, X's per-request billing and on-call time. Unified APIs bill per connected account or per post, so you can model the bill before you ship. See cost at scale.
When do native platform APIs make sense?
You're building ad tech itself. Zernio's Ads API covers campaigns, boosted posts, audiences and reporting on 8 ad networks, which is what most products need. If your product is a bid optimizer or an auction-analytics tool, you'll want each network's full Marketing API underneath.
Your product is deep analytics on one or two platforms. Native APIs expose metrics no unified layer normalizes: Instagram story navigation, YouTube traffic sources, LinkedIn follower demographics by job function.
You're building platform-native experiences. Live streaming controls, YouTube chapters and captions, TikTok's Research API. These need the platform's own API.
Stop building social integrations from scratch.
One API call to publish, schedule, and manage posts across 16 platforms.
Best unified social media APIs for developers
1. Zernio: best social media API for SaaS products, agencies and AI agents
Zernio is marketing infrastructure for products and AI agents. Social is where it started and still its biggest product: one REST API and one API key for 16 channels, covering posting, comments, DMs, analytics and ads. The same key also reaches WhatsApp, SMS and calls when your product needs them.
Channels (16):
- Social: X, Instagram, TikTok, LinkedIn, Facebook, YouTube, Threads, Reddit, Pinterest, Bluesky, Google Business
- Messaging: WhatsApp, Telegram, Discord, Slack, iMessage
Ad networks (8): Meta (Facebook and Instagram), Google, TikTok, LinkedIn, Pinterest, X, OpenAI (ChatGPT ads) and Reddit.
Key features:
- One request shape for every channel. Zernio handles format differences, character limits and media specs per platform
- OAuth-as-a-service: your users connect their own accounts through one connect URL, and
headless=truemakes the flow fully white-label - Unified inbox: DMs, comments and reviews across platforms, with realtime webhooks
- Analytics API: impressions, reach, engagement and follower growth, normalized across channels
- Ads API: boost organic posts or run standalone campaigns on 8 ad networks
- Bulk scheduling via CSV, with a dry-run mode
- Comment-to-DM automation
- 8 SDKs: Node.js, Python, Go, Ruby, Java, PHP, .NET, Rust
- Hosted MCP server at mcp.zernio.com, plus a CLI with structured JSON output
- Vercel Chat SDK adapter, and n8n, Make and Zapier integrations
Who runs on it:
- Readdy (no-code website builder): 2,349 customer accounts connected and 15,042 posts published, with the first live version in about a week
- Vibiz (AI platform): 70,000+ posts automated, with posting, ads, inbox and analytics built in one week
- ACT.agency (Amsterdam agency): 8 white-label client workspaces, 1,336 ads managed and 86,000 messages a month through the API
- MoFlo (AI growth platform): switched from Ayrshare after about 6 months to run account connection on its own domain
Pricing:
Graduated pay-per-account. Every feature is included from the first account, with no add-ons and no feature gates.
| Connected accounts | Per account/month |
|---|---|
| First 2 accounts | Free |
| Accounts 3-10 | $6 |
| Accounts 11-100 | $3 |
| Accounts 101 and up | $1 (no cap) |
What this looks like in practice:
| Scale | Monthly cost |
|---|---|
| 10 accounts | $48/mo |
| 50 accounts | $168/mo |
| 100 accounts | $318/mo |
| 500 accounts | $718/mo |
| 1,000 accounts | $1,218/mo |
| 2,000 accounts | $2,218/mo |
Requirements: Sign up, grab an API key, make your first call. No app review, no approval process, no demo call. The first 2 accounts are free immediately.
What Zernio doesn't cover: TikTok and Pinterest have no inbox API at the platform level, so there are no DMs on either. OpenAI Ads is the newest network and still early.
Best for: SaaS products where end users connect their own accounts, agencies building white-label client dashboards, AI content tools, and AI agents that publish, reply and boost.
Performance: 99.7%+ uptime, under 50ms response times. Live production data, failures included, at zernio.com/open.
2. Ayrshare: unified social media API
Ayrshare is a unified social media API covering 14+ networks, with posting, analytics, comments and an MCP server. Pricing is plan-based: each plan includes a set number of profiles, with per-profile overage above that.
Platforms supported: 14+ networks, including Facebook, Instagram, X, LinkedIn, TikTok, YouTube, Threads, Pinterest, Reddit, Bluesky, Telegram, Snapchat and Google Business Profile.
Key features:
- Posting, scheduling and analytics across its networks
- Comments and messaging on supported networks
- Webhooks for post events
- An MCP server, added recently
- SDKs in most major languages
Pricing:
| Plan | Monthly | Profiles |
|---|---|---|
| Premium | $149/mo | 1 |
| Launch | $299/mo | Up to 10 |
| Business | $599/mo | 30, then $8.99 each (31-100), $3.49 (101-500), $2.49 (500+) |
| Enterprise | Custom | From 300 |
How the price compares: Ayrshare starts at $149/mo for one profile and charges $8.99 per profile from 31 to 100. At list price, 100 profiles come to about $1,228/mo and 1,000 to about $3,869/mo. The same counts on Zernio cost $318/mo and $1,218/mo, and the first 2 accounts are free.
Requirements: Sign up and go for standard use. Enterprise requires a sales conversation.
Best for: Teams already integrated with Ayrshare and a small, steady number of profiles. If you need your users to connect accounts on your own domain, MoFlo's move to Zernio is a useful read.
→ Zernio vs. Ayrshare detailed comparison
3. Upload-Post: posting API with built-in video processing
Upload-Post started as a simpler posting API and now reaches a long list of destinations, including developer blogs and newsletters.
Platforms supported: 22, including TikTok, Instagram, YouTube, Facebook, LinkedIn, X, Threads, Pinterest, Reddit, Bluesky, Google Business, Discord, Telegram, Slack, Mastodon, Dev.to, Hashnode and WordPress.
Key features:
- FFmpeg-based video processing API
- Open-source (MIT) MCP server with 40 tools for publishing, scheduling, analytics, comments and DMs
- n8n community node with templates
Pricing:
| Plan | Monthly | Profiles | Uploads |
|---|---|---|---|
| Free | $0 | 2 | 10/month (no TikTok) |
| Basic | $24/mo | 5 | Unlimited |
| Professional | $50/mo | 25 | Unlimited |
| Advanced | $147/mo | 75 | Unlimited |
| Business | $438/mo | 225 | Unlimited |
What's missing: No ads API. Comments and DMs are exposed through its MCP tools rather than described as a standalone inbox API. The listed plans top out at 225 profiles.
Best for: Video-heavy posting and long-tail destinations like Dev.to, Hashnode or Mastodon.
4. bundle.social: unlimited accounts, priced by post volume
bundle.social is a unified posting and comments API that bills per organization, by post volume instead of by connected account.
Platforms supported: 15 listed, including Instagram, TikTok, Facebook, LinkedIn, YouTube, X, Threads, Pinterest, Reddit, Bluesky, Mastodon, Slack, Discord, Google Business Profile and Snapchat.
Pricing: Free (3 accounts, 20 posts a month), Pro at $100/mo (unlimited accounts, 10,000 posts, 5,000 comments), Business at $400/mo (100,000 posts) and custom Enterprise. X posts bill separately from a prepaid credit balance.
What's missing: DMs and automations are in beta and not on the free plan. No ads API is listed.
Best for: Products with many connected accounts that each post rarely, where a post-volume bill stays lower than a per-account one.
5. Outstand: pay-as-you-go posting with reselling allowed
Outstand is a unified API for posting, scheduling, comments, DMs and analytics, metered per post.
Platforms supported: 12: X, LinkedIn, Instagram, TikTok, Facebook, Threads, Bluesky, YouTube, Pinterest, Google Business Profile, Vimeo and Reddit. Eight run on Outstand's managed keys. X, Google Business Profile, Vimeo and Reddit need your own developer app.
Pricing: $19/mo including 3,000 posts, then $0.007 a post up to 10,000 and $0.005 after. Business is $129/mo with 50,000 posts and permits reselling. Both list unlimited connected accounts.
What's missing: No official SDKs mentioned, and no ads API. Bringing your own X and Reddit apps puts app review back on your plate for those networks.
Best for: Usage-metered products and resellers that are comfortable owning a few developer apps.
6. Postiz: open-source scheduler with an API
Postiz is an open-source social scheduler with a public API, an MCP server and a CLI on every plan. Self-hosting is available, and the hosted version gets new features first.
Platforms supported: About 30 channels, including X, LinkedIn, Instagram, Facebook, TikTok and YouTube.
Pricing (hosted, monthly): $29 for 5 channels, $39 for 10, $49 for 30, $99 for 100. Annual billing takes about 20% off.
The tradeoff: If you self-host, platform app approvals, token refresh and breaking API changes are yours to handle.
Best for: Teams that want to own and modify the code, or need to run on their own infrastructure.
7. Buffer API: for channels you already manage in Buffer
Buffer's public API covers posts and scheduling, post metrics, ideas and tags, with API-key access. It's documented to work with Claude, ChatGPT, Cursor, Raycast and Perplexity.
The tradeoff: Buffer is built for people managing their own channels. Its developer docs don't cover comments or DMs, or a flow for your end users to connect their accounts inside your product.
Best for: Automating a Buffer account you already run.
8. Post for Me: cheapest entry point for posting only
Post for Me is a posting API that starts at $10/mo for up to 1,000 successful posts, with unlimited accounts, projects and API keys.
Platforms supported: 9: TikTok, Facebook, Instagram, X, LinkedIn, Pinterest, Bluesky, Threads and YouTube.
What's missing: It reads account feeds and post analytics, but lists no comments or DMs, and no ads.
Best for: Side projects and MVPs that only need to publish.
9. Unipile: LinkedIn and messaging-focused API
Unipile specializes in LinkedIn inbox access and messaging APIs. It's a messaging layer, not a posting competitor.
Platforms supported: LinkedIn (primary), plus Email, WhatsApp, Instagram DMs, Messenger.
Key features:
- LinkedIn inbox read/write (this is the core differentiator)
- Connection request management
- DM automation across messaging platforms
- CRM-style contact enrichment
Pricing: ~$500/mo at scale. Custom enterprise pricing.
Rate limits: Dependent on platform limits (especially LinkedIn's per-member throttling).
Requirements: Sign up. Platform limits apply.
What's missing: No social posting. No analytics. No MCP server. Narrow scope by design.
Best for: LinkedIn outreach tools, sales engagement platforms, and anything that needs programmatic LinkedIn inbox access. If you also need multi-platform posting, you'll need Zernio alongside Unipile (or instead of it, if DMs on LinkedIn are a secondary need).
10. Octolens: the unified API for social listening
The APIs above solve posting, sending DMs, reviewing ads and accessing analytics. Octolens solves the reverse: one endpoint that returns every mention of a keyword across the social web as structured JSON.
Platforms supported: Reddit, X/Twitter, LinkedIn, YouTube, TikTok, Bluesky, Hacker News, GitHub, Stack Overflow, plus news, newsletters, and podcasts (15+ sources).
Key features:
- One endpoint, one schema for mentions from all sources
- AI relevance filtering and sentiment (handles common-word brand names)
- Webhooks for real-time delivery into your own pipeline
- MCP server + open-source CLI for agent workflows
Pricing: $199/mo (15k mentions, 10 keywords) to $599/mo (50k, 40 keywords). API, webhooks, and MCP on every plan.
Rate limits: Mention volume is plan-based, not request-throttled.
Requirements: Sign up, add keywords.
What's missing: No posting, no DMs, no ads data. Read-only by design.
Best for: Agents and internal tools that need to know what people are saying: triaging public complaints, turning mentions into CRM leads or tickets, brand monitoring in your own stack. If your agent posts via Zernio, Octolens is how it hears the rest of the internet.
11. Phyllo: creator data API
Phyllo sells social data APIs for creator platforms and influencer marketing: audience, engagement and income data across 20+ platforms, plus a publishing product. Pricing is quote-based.
Best for: Influencer marketing and creator-economy products that need to read creator data. For publishing and engagement on your users' own accounts, pair it with a posting API.
What can each unified social media API actually do?
Posting is table stakes. The real question is whether the API covers the rest of the social operation. Here's what each vendor documents, checked October 2026. "Not listed" means we didn't find it on the vendor's site, so confirm with them if it matters to you.
| Capability | Zernio | Ayrshare | Upload-Post | bundle.social | Outstand | Postiz |
|---|---|---|---|---|---|---|
| Channels | 16 | 14+ | 22 | 15 | 12 | ~30 |
| Publish and schedule | Yes | Yes | Yes | Yes | Yes | Yes |
| Comments | Yes | Yes | Via MCP tools | Yes | Yes | Not listed |
| DMs / inbox | Yes, incl. WhatsApp and iMessage | Yes | Via MCP tools | Beta, paid plans | Yes | Not listed |
| Analytics | Yes | Yes | Yes | Yes | Yes | Not listed |
| Ads API | Yes, 8 ad networks | Not listed | Not listed | Not listed | Not listed | Not listed |
| MCP server | Yes, hosted | Yes | Yes, open source | Yes | Yes | Yes |
| Your own developer apps needed | No | No | No | No | For X, Reddit, Google Business, Vimeo | When self-hosting |
| Official SDKs | 8 languages | Multiple | Not listed | Not listed | Not listed | Not listed |
| Pricing model | Per account, graduated | Per profile | Per profile tier | Per post volume | Per post | Per channel |
What does a social media API cost at scale?
Same API category, different pricing philosophies. Here's the list price at three common sizes.
| API | 10 accounts | 100 accounts | 1,000 accounts |
|---|---|---|---|
| Zernio | $48/mo | $318/mo | $1,218/mo |
| Ayrshare | $299/mo | ~$1,228/mo | ~$3,869/mo (or Enterprise quote) |
| Upload-Post | $50/mo | $438/mo | Not listed |
| Postiz (hosted) | $39/mo | $99/mo | Not listed |
| bundle.social | $100/mo up to 10,000 posts, $400/mo up to 100,000, any number of accounts | ||
| Outstand | $19/mo for 3,000 posts, then $0.005 to $0.007 a post, any number of accounts | ||
| Post for Me | From $10/mo for 1,000 posts, any number of accounts | ||
Post-metered plans look cheaper on paper when each account posts rarely. Before you compare, check what the plan includes: inbox, analytics and ads are where the products differ most, and X usage is billed on top almost everywhere. Ayrshare figures are our calculation from its published per-profile rates.
How does authentication work across these APIs?
The auth story is the biggest hidden cost of going native, and the biggest thing a unified API abstracts.
With native APIs, every platform is its own project. Meta uses OAuth 2.0 with Business Verification and App Review. X uses OAuth 1.0a or 2.0 PKCE. LinkedIn gates company-page posting behind a reviewed API product and ships a new API version every month. Each has its own scopes, token refresh cycle and expiry behavior. You build and maintain all of it.
With a unified social media API like Zernio, you authenticate once. One API key is a single bearer credential (Authorization: Bearer YOUR_API_KEY) for all 16 channels. You never handle per-platform OAuth yourself.
When you're building a SaaS where end-users connect their own accounts, Zernio runs OAuth-as-a-service. You send the user to one connect URL and Zernio handles the platform token, refresh, and expiry:
curl "https://zernio.com/api/v1/connect/instagram?profileId=PROFILE_ID&redirect_url=https://your-app.com/callback" \
-H "Authorization: Bearer YOUR_API_KEY"The response returns an authUrl. Redirect your user there, they authorize, and the account lands in their profile. Add headless=true for a fully white-label flow with no Zernio-hosted screens.
Best native platform APIs for developers
These are the official APIs from the platforms themselves. Use them when one platform is your product and you need capabilities no unified layer exposes. Limits and prices below were checked against each platform's own docs in October 2026.
12. Meta Graph API: Facebook and Instagram
What it covers: Publishing to Facebook Pages and Instagram professional accounts, Messenger, Instagram Direct, WhatsApp Business, Reels, Stories, carousels, ads and insights.
Key features:
- Instagram Reels, Stories, carousels and product tags
- Facebook Page publishing and Messenger bots
- Full ad management through the Marketing API
- Instagram DMs for professional accounts, inside the 24-hour messaging window
- Webhooks for comments and messages
Pricing: Free to call. Rate limits and app review are the constraint, not cost.
Rate limits:
- Instagram publishing: 100 API-published posts per account in a rolling 24 hours (a carousel counts as one)
- App and business use case limits scale with your app's active users and the account's activity
- Marketing API: separate limit tiers based on ad spend
Requirements:
- A Meta developer account and a registered app
- Business Verification for production access
- App Review for permissions like
instagram_content_publishandpages_manage_posts - Instagram professional (Business or Creator) accounts only. Pages that require Page Publishing Authorization can't publish until it's complete
When to use it: Ad tech, deep Instagram analytics, Story-specific workflows and Messenger bots. For Instagram and Facebook as two of many channels, Zernio covers both without your own app review.
Docs: Instagram content publishing
13. X (Twitter) API: official X developer API
What it covers: Posting, timelines, search, Direct Messages, user data and real-time filtered streams.
Key features:
- Create, delete and like posts; manage threads
- Home and mentions timelines
- Filtered stream for keyword and topic monitoring
- User lookup, followers and following
- Direct Messages, polls and media
Pricing (pay-per-usage):
| Action | Cost |
|---|---|
| Post read | $0.005 per post returned |
| Owned reads (your own posts, mentions, followers) | $0.001 per resource |
| Post create | $0.015 per request |
| Post create with a URL | $0.200 per request |
| Higher volumes | Enterprise, by application |
Limits: Pay-per-usage plans are capped at 3 million post reads per billing cycle. Repeat requests for the same resource within a 24-hour UTC window are generally not charged again. You can set a spending limit, after which requests are blocked until the next cycle.
Requirements: A developer account and app registration in the X Developer Console. Automated posting that imitates organic activity breaks X's rules.
When to use it: Real-time monitoring, search and X-specific products. If you post to X as one of many channels, Zernio passes X usage through at these same rates with no markup. More detail in our X API pricing guide.
Docs: docs.x.com pricing
14. TikTok API: official TikTok developer platform
What it covers: Video and photo publishing, account data, Login Kit, and the Research API.
Key features:
- Content Posting API for videos and, now, photos
- Login Kit for "Sign in with TikTok"
- Display API for profile and video lists
- Research API for qualifying researchers
- TikTok Business API (Spark Ads, branded content) as a separate application
Pricing: No per-call fees. Access is permission-based.
Requirements:
- Register at developers.tiktok.com and create an app
- Until your app passes TikTok's audit, everything it posts is restricted to private viewing
- Photos must come from a verified domain or URL prefix
- Business API access needs its own application through TikTok for Business
When to use it: TikTok-first products, Spark Ads and research use. For TikTok as one of many channels, a unified API publishes publicly without waiting on your own audit.
Docs: Content Posting API
15. LinkedIn API: official LinkedIn developer platform
What it covers: Member and company-page posts, comments and reactions, page analytics, Sign In with LinkedIn, and (through the Marketing APIs) ads and Lead Gen Forms. LinkedIn's API docs now live on Microsoft Learn.
Key features:
- Posts API: text, images, video, documents, articles, multi-image posts and polls (organic carousels aren't supported, carousels are sponsored-only)
- Targeted organic posts to a follower segment of 300+ members
- Page analytics: impressions, clicks, follower demographics
- Campaign management and Lead Gen Forms through the Marketing APIs
Pricing: Free to call.
Permissions that matter:
w_member_social: post, comment and like as the signed-in memberw_organization_social: post as a company page, only for members with an Administrator, Content Admin or Direct Sponsored Content Poster role on that pager_member_social: reading a member's posts is restricted to approved partners
Requirements: A LinkedIn developer app, a reviewed API product for page and ads access, and the Linkedin-Version header on every call. LinkedIn ships a new version monthly and sunsets old ones on a schedule (the November 2025 version sunsets on November 16, 2026), so budget for regular migrations.
When to use it: LinkedIn ad campaigns, Lead Gen automation and deep page analytics. For LinkedIn posting as part of a multi-channel product, Zernio covers member and page posting without the review or the monthly migrations. See our LinkedIn posting guide.
Docs: Posts API on Microsoft Learn
16. YouTube Data API v3: official YouTube API
What it covers: Video uploads, playlists, channel data, comments, captions and live streaming.
Key features:
- Upload videos and manage metadata (titles, descriptions, tags, chapters)
- Playlist and channel management
- Comment listing, replies and moderation
- Live broadcasts and streams
- Captions and subtitles
Pricing and quota: Free within quota. Each project gets 10,000 units a day for most endpoints. Uploads (videos.insert) and search.list now have their own allocation of 100 calls a day each, at 1 unit per call. Writes like commentThreads.insert cost 50 units. More quota needs Google's compliance audit.
Requirements: A Google Cloud project, OAuth 2.0 for anything on a user's channel, and an API key for public reads.
When to use it: YouTube-specific products: chapters, captions, live streaming and Shorts insights. For YouTube as one of many channels, Zernio handles YouTube uploads without you managing quota or audits.
Docs: YouTube quota costs
17. Reddit API: official Reddit developer platform
What it covers: Submitting posts (text, link, image, video, polls), comments and replies, voting, subreddit data and moderation tools.
Pricing: Free for approved non-commercial use. Commercial use needs a separate agreement with Reddit, and Reddit doesn't publish a commercial rate card. Figures that circulate online are third-party reports, so plan around a quote from Reddit itself.
Requirements:
- A Reddit account and a registered app
- Approval before your app can access Reddit data. Self-service app registration is no longer instant
- OAuth 2.0 for user actions, with rate limits applied per OAuth client
- A commercial agreement for any monetized product
When to use it: Community monitoring, moderation tools and subreddit analytics. For posting to Reddit as one of many channels, Zernio covers Reddit without your own commercial contract.
Docs: reddit.com/dev/api
18. Pinterest API: official Pinterest developer platform
What it covers: Pin creation and management, board management, catalog publishing, audience insights, and organic analytics for Pinterest Business accounts.
Key features:
- Create and update Pins (images, videos, carousels) across boards
- Board management: create, list, update boards and sections
- Pinterest Catalogs: bulk product feed publishing for shopping
- Audience insights: demographics, interests, engagement by pin
- Conversion tracking and Pinterest Tag events
- Trends API: search interest data over time
Pricing: Free. Pinterest charges nothing for API access.
Rate limits:
- Trial access (Sandbox): 1,000 requests/day
- Standard access: up to 100 requests/second per user per app
- Rate limit headers returned with each response so you can track consumption
Requirements:
- Pinterest Business account
- Pinterest Developer account and registered app at developers.pinterest.com
- Start with Trial (Sandbox) access by default; must request Standard access upgrade through the Developer dashboard with a use-case review
- OAuth 2.0 for all user-authenticated actions
- Standard access review is manual; Pinterest evaluates your app before approving production access
When to use it: Pinterest-specific workflows: product catalog publishing, Idea Pin creation, or deep pin analytics. For publishing to Pinterest as part of a multi-platform strategy, Zernio's Pinterest API integration works without the manual approval process.
Website: https://developers.pinterest.com/
19. Threads API: official Meta developer platform for Threads
What it covers: Publishing posts and replies to Threads, pulling post analytics, and managing threads on behalf of authenticated users. Part of Meta's developer platform, launched in late 2024.
Key features:
- Publish Threads posts: text, images, and videos
- Reply management: post replies, access reply threads
- Post insights: views, likes, replies, reposts, quotes
- User profile data for authenticated accounts
- Search (500 queries per rolling 7-day period)
- Embed posts in external web pages
Pricing: Free. Meta does not charge for Threads API access.
Rate limits:
- Publishing: 250 posts per 24-hour period per profile
- Replies: 1,000 replies per 24-hour period per profile
- Search: 500 queries per rolling 7-day window
- Embedding: up to 5,000,000 requests per 24-hour period
- App-level call count: 4,800 x number of impressions per rolling 24-hour window
Requirements:
- Facebook Developer account and registered Meta app
- OAuth 2.0 user authentication
- App Review required to use most Threads permissions; key scopes:
threads_basic,threads_content_publish - App Review is manual and takes multiple days; Meta evaluates your use case before granting production access
- Users must have a Threads account connected to their Instagram account
When to use it: Threads-first workflows where you need reply threading, fine-grained Threads analytics, or native Threads features not yet available through unified APIs. For publishing to Threads as part of a multi-platform distribution strategy, Zernio covers Threads alongside the other 15 channels in one call.
Website: https://developers.facebook.com/docs/threads/
20. Bluesky API: open AT Protocol
What it covers: Posting, replies, likes, follows, feeds and DMs on Bluesky, over the open AT Protocol.
Pricing: Free. There's no developer program to apply to.
Rate limits:
- Writes: 5,000 points per hour and 35,000 per day per account. A create costs 3 points, an update 2 and a delete 1, so about 1,666 new posts an hour
- Logins: 30 sessions per 5 minutes and 300 a day per account, so cache and refresh sessions instead of logging in per post
Requirements: A Bluesky account with an app password or OAuth.
When to use it: Bluesky-native apps, custom feeds and bots. For Bluesky as one of many channels, Zernio covers Bluesky, including comments and DMs.
Docs: Bluesky rate limits
Native platform APIs: what "free" actually costs
Native APIs are mostly free to call, but scaling them costs in other ways.
| Platform API | Direct cost | Hidden cost |
|---|---|---|
| Meta Graph API | Free to call | Business Verification, App Review, 100 Instagram posts per account per day |
| X API | $0.015 per post, $0.20 with a URL, $0.005 per read | Costs climb with volume; 3M read cap before Enterprise |
| TikTok API | Free if approved | Posts stay private until your app passes audit |
| LinkedIn API | Free to call | Product review for page and ads access; monthly API versions to migrate |
| YouTube Data API | Free within quota | 100 uploads a day per project; audit for more |
| Reddit API | Free for non-commercial use | Approval required; commercial use needs a negotiated contract |
| Bluesky API | Free | Session and write budgets to manage yourself |
The real cost of native APIs is engineering time: building each integration, keeping up when platforms deprecate endpoints, and handling rate-limit failures on call. A unified API takes all three off your team.
Social media APIs for AI agents and MCP
If you're building an AI agent, the API surface design matters as much as the features.
An agent needs to:
- Know what tools are available (tool discovery)
- Call those tools with well-typed inputs (tool execution)
- Parse structured responses without custom transformation (output normalization)
- Handle errors and retry (reliability)
Raw platform APIs weren't designed for LLMs, so you'd write a tool wrapper around each one before your agent could use it. Most unified APIs now ship an MCP server (Zernio, Ayrshare, Upload-Post, Outstand and Postiz all have one). The difference is what's behind it.
The Zernio MCP server at mcp.zernio.com is hosted, works with Claude, ChatGPT, Codex, Cursor and VS Code, and discovers tools on demand so the agent only loads what the task needs. Behind it sits the whole API, not just posting:
- Create and schedule posts across 16 channels
- Read and reply to comments and DMs, including WhatsApp
- Pull follower analytics and engagement metrics
- Manage posting queues and bulk operations
- Launch, pause and report on ads across 8 ad networks
That last one is what lets an agent close the loop on its own: publish, read what performed, boost the winner.
The CLI outputs structured JSON for every command, so it pipes straight into agent reasoning loops. For a full walkthrough, see the social media API for AI agents guide.
Key takeaway
If your users connect their own social accounts, or your agent needs to publish, reply and boost, start with a unified API. Zernio covers the most ground in one integration (16 channels, inbox, analytics and 8 ad networks) and its per-account price falls as you grow, which is why SaaS teams like Readdy and agencies like ACT.agency build on it.
Pick a post-metered API when you only publish and each account posts rarely. Go native when a single platform is your product.
FAQ
What's the best social media API for a SaaS product?
Zernio. It connects 16 channels through one API, and it runs account connection for you: send each user to one link, and Zernio connects their accounts and keeps the tokens fresh. Turn on headless=true and the flow runs under your own brand. Readdy uses it for 2,349 customer accounts, and pricing drops to $1 an account past 100.
What's the best Ayrshare alternative?
Zernio, if cost at scale or white-label connection is the problem. At list price, 100 connected accounts cost about $1,228/mo on Ayrshare and $318/mo on Zernio, and Zernio adds ads and WhatsApp in the same API. MoFlo switched after about 6 months to run account connection on its own domain.
Can you run social ads through an API without creating a Meta app?
Yes. Zernio is a Meta Business Partner, and its Ads API creates, pauses, edits and reports on Meta campaigns. The same integration covers Google, TikTok, LinkedIn, Pinterest, X, OpenAI (ChatGPT) and Reddit ads. You can also run it from an AI assistant through Zernio's MCP server.
Which social media API is best for AI agents?
One with a hosted MCP server and the full API behind it. Zernio's MCP server at mcp.zernio.com discovers tools on demand and covers publishing, comments, DMs, analytics and ads, so an agent can publish, analyze and boost without custom wrappers. It works with Claude, ChatGPT, Cursor and any MCP client.
Which social media APIs have an MCP server?
Zernio, Ayrshare, Upload-Post, bundle.social, Outstand and Postiz all document one. Zernio's also reaches ads on 8 networks and messaging channels like WhatsApp and iMessage, so one agent can run organic, paid and inbox work.
What is a unified social media API and how does it work?
A unified social media API sits on top of multiple platform APIs and exposes one consistent endpoint. You make one API call with your content, and the unified layer handles per-platform auth tokens, format normalization, media transcoding, rate-limit retries and delivery to each platform.
How long does it take to integrate a social media API?
With a unified social media API like Zernio, most developers have a working integration in under an hour. Building native integrations for 16 channels yourself takes months: separate OAuth apps and reviews, media handling per platform, rate-limit management, and ongoing maintenance as platforms change.
What are the rate limits for major social media APIs?
Instagram allows 100 API-published posts per account per day. YouTube gives each project 10,000 quota units a day plus 100 uploads. X caps pay-per-usage plans at 3 million post reads a month. Bluesky allows 35,000 write points per account per day. Zernio manages platform limits for you and gives you one request budget: 60/minute free, 600/minute from 3 to 2,000 accounts, and 1,200/minute beyond. On a 429, honor the Retry-After header.
Is there a free social media API for developers?
Yes. Zernio's free tier covers 2 connected accounts with every feature. Upload-Post's free plan has 2 profiles and 10 uploads a month, and bundle.social's has 3 accounts and 20 posts. Most native platform APIs are free to call within their limits.
What's the best API for social media analytics?
For unified cross-platform analytics, Zernio's Analytics API returns impressions, reach, engagement, saves, clicks and follower growth across platforms, plus per-post daily timelines. Native APIs give the deepest single-platform metrics.
Which social media API handles video best?
Unified APIs normalize video specs per platform so you upload once. Zernio handles per-platform transcoding, aspect ratios and size limits automatically. Upload-Post exposes an FFmpeg-based processing API if video editing is your core need. Native APIs (YouTube Data API, TikTok Content Posting API) give the most control but need per-platform upload handling.
What's the difference between a social media API and a social media data API?
A social media API usually means publishing and management on accounts you or your users own: posts, scheduling, comments and DMs. A social media data API (like Brandwatch, Data365 or Phyllo) reads public or creator data for monitoring, sentiment and influencer research. Zernio is the first kind, and its analytics API covers performance data for every connected account.
