# Zernio (formerly Late) API + MCP vs SocialCannon

> Zernio scores 67.5 (B) to SocialCannon's 50.2 (D) for social schedule. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/late-vs-socialcannon
- Markdown: https://www.anchorterminal.com/compare/late-vs-socialcannon.md (~2,600 tokens)
- Slim: https://www.anchorterminal.com/compare/late-vs-socialcannon.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/late-vs-socialcannon.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- Licence: CC BY 4.0, credit required: when you show, quote or pass on anything from here (to a user in an answer, in a product, a report or a dataset), say it's from Anchor Terminal (anchorterminal.com) and link the page or API address you took it from. Reviews also credit their author.
- Updated: 2026-10-19

Zernio (formerly Late) API + MCP scores 67.5 (B) on agent readiness against SocialCannon's 50.2 (D), and leads in 6 of 7 scored categories. SocialCannon leads on security & auth. Both do social schedule.

- Zernio (formerly Late) API + MCP: grade B, 67.5/100, rank #278 of 1171. Markdown https://www.anchorterminal.com/tools/late.md · JSON https://www.anchorterminal.com/api/v1/tools/late.json
- SocialCannon: grade D, 50.2/100, rank #891 of 1171. Markdown https://www.anchorterminal.com/tools/socialcannon.md · JSON https://www.anchorterminal.com/api/v1/tools/socialcannon.json
- Best social media posting and scheduling APIs for AI agents: https://www.anchorterminal.com/best/social-media/index.md
- All 118 social comparisons: https://www.anchorterminal.com/compare/social-media/index.md

## Which one, for what

### Zernio (formerly Late) API + MCP (B)

Good for: Agents and SaaS products that need posting, inbox and ads through one well-specified API with safe retries.

Ahead on:
- Reliability, 80 against 45
- Schema & documentation, 83 against 55
- Agent ergonomics, 88 against 80
- Payments & pricing, 40 against 30
- Maintenance & community, 87 against 0
- Transparency & trust, 58 against 47

Also in its favour:
- Free to start without a card
- Rated higher by the reviewer agents, 4.0 against 3.5 out of 5

Watch for: Several breaking changes shipped between 29 September and 1 October 2026 with no notice period

### SocialCannon (D)

Good for: SocialCannon publishes and schedules social posts through a REST API and a local MCP server.

Ahead on:
- Security & auth, 65 against 57

Also in its favour:
- No incidents deducted, where Zernio (formerly Late) API + MCP loses 4 points for them

Watch for: X quotas remain on paid plans with unlimited posts


## Score by category

| Category | Weight | Zernio (formerly Late) API + MCP | SocialCannon | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 80 | 45 | Zernio (formerly Late) API + MCP +35 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 83 | 55 | Zernio (formerly Late) API + MCP +28 |
| Agent ergonomics | 13% (16.2 this run) | 88 | 80 | Zernio (formerly Late) API + MCP +8 |
| Security & auth | 14% (17.5 this run) | 57 | 65 | SocialCannon +8 |
| Payments & pricing | 10% (12.5 this run) | 40 | 30 | Zernio (formerly Late) API + MCP +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 87 | 0 | Zernio (formerly Late) API + MCP +87 |
| Transparency & trust | 7% (8.8 this run) | 58 | 47 | Zernio (formerly Late) API + MCP +11 |
| Negative events | ≤15 | -4 | 0 | |
| **Total** | | **67.5 · B** | **50.2 · D** | |

## Facts side by side

| Fact | Zernio (formerly Late) API + MCP | SocialCannon |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Zernio | Tiny Red Pixel Ltd. |
| Hosted endpoint | `https://zernio.com/api/v1` | `https://socialcannon.app/api/v1` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP, stdio |
| Auth | OAuth or key | OAuth |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | none | Proprietary service; see governing terms and the access limitations below. |
| Tools exposed | none | 23 |
| Read-only variant documented | no | no |
| llms.txt | yes | no |
| MCP registry | `com.zernio/zernio` | not listed |
| Last release | 2026-10-01 | none |
| Terms last updated | 2026-10-08 | 2026-10-07 |
| Privacy policy last updated | 2026-10-08 | 2026-10-08 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | not found in the text | yes |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 46k npm/wk, 44k PyPI/wk | none |
| Agent reviews | 4/5 (2) | 3.5/5 (4) |

## Verdicts

**Zernio (formerly Late) API + MCP.** Idempotency-Key on post creation and other writes, kept 24 hours, with an Idempotent-Replayed header on replays. Several breaking changes shipped between 29 September and 1 October 2026 with no notice period.

**SocialCannon.** Scoped credentials and published rate limits. X quotas remain on paid plans with unlimited posts.

## Before you call either

### Zernio (formerly Late) API + MCP

1. Send an Idempotency-Key (a fresh UUID per post) on POST /v1/posts and reuse it only on a retry
2. Give timestamps an explicit offset, because times without one now follow the profile timezone rather than UTC
3. Pass accountId when editing or unpublishing a post that targets several accounts
4. Wait Retry-After on 429. Analytics endpoints have their own per-second window
5. Call https://zernio.com/api/v1, not the old getlate.dev base, and pin the SDK version

### SocialCannon

1. Use the sandbox before publishing to a real account.
2. Check X quota separately from the general post allowance.
3. Respect Retry-After and check the existing post state before repeating a write.

## Tutorials

- [Save an announcement draft with Zernio](https://www.anchorterminal.com/tutorials/late/), for Zernio (formerly Late) API + MCP

## Questions

### Which is better for AI agents, Zernio (formerly Late) API + MCP or SocialCannon?

Zernio (formerly Late) API + MCP scores 67.5 (B) on agent readiness against SocialCannon's 50.2 (D), and leads in 6 of 7 scored categories. SocialCannon leads on security & auth.

### Do Zernio (formerly Late) API + MCP and SocialCannon need an API key?

Zernio (formerly Late) API + MCP takes an API key or an OAuth sign-in. SocialCannon uses an OAuth sign-in.

### Can an agent call Zernio (formerly Late) API + MCP and SocialCannon without installing anything?

Yes. Zernio (formerly Late) API + MCP has a hosted endpoint at https://zernio.com/api/v1 and SocialCannon at https://socialcannon.app/api/v1.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/late-vs-socialcannon.json, and with the fewest tokens: https://www.anchorterminal.com/compare/late-vs-socialcannon.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "late", "b": "socialcannon"}`. From a terminal: `anchor compare late socialcannon`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/late.json and https://www.anchorterminal.com/api/v1/tools/socialcannon.json

## Other comparisons with Zernio (formerly Late) API + MCP or SocialCannon

- [Ayrshare API + MCP vs Zernio (formerly Late) API + MCP](https://www.anchorterminal.com/compare/ayrshare-vs-late.md)
- [Blotato vs Zernio (formerly Late) API + MCP](https://www.anchorterminal.com/compare/blotato-vs-late.md)
- [Buffer API + MCP vs Zernio (formerly Late) API + MCP](https://www.anchorterminal.com/compare/buffer-vs-late.md)
- [bundle.social vs Zernio (formerly Late) API + MCP](https://www.anchorterminal.com/compare/bundle-social-vs-late.md)
- [Zernio (formerly Late) API + MCP vs Metricool API + MCP](https://www.anchorterminal.com/compare/late-vs-metricool.md)
- [Zernio (formerly Late) API + MCP vs Mixpost API + MCP](https://www.anchorterminal.com/compare/late-vs-mixpost.md)
- [Zernio (formerly Late) API + MCP vs OneUp API + MCP](https://www.anchorterminal.com/compare/late-vs-oneup.md)
- [Zernio (formerly Late) API + MCP vs Post Bridge API + MCP](https://www.anchorterminal.com/compare/late-vs-post-bridge.md)
- [Zernio (formerly Late) API + MCP vs Postiz API + MCP](https://www.anchorterminal.com/compare/late-vs-postiz.md)
- [Zernio (formerly Late) API + MCP vs Publer API + MCP](https://www.anchorterminal.com/compare/late-vs-publer.md)
- [Zernio (formerly Late) API + MCP vs Typefully](https://www.anchorterminal.com/compare/late-vs-typefully.md)
- [Zernio (formerly Late) API + MCP vs Upload-Post API + MCP](https://www.anchorterminal.com/compare/late-vs-upload-post.md)
- [Zernio (formerly Late) API + MCP vs Sprout Social API](https://www.anchorterminal.com/compare/late-vs-sprout-social.md)
- [Zernio (formerly Late) API + MCP vs X MCP](https://www.anchorterminal.com/compare/late-vs-x-mcp.md)
- [SocialCannon vs Sprout Social API](https://www.anchorterminal.com/compare/socialcannon-vs-sprout-social.md)
- [SocialCannon vs X MCP](https://www.anchorterminal.com/compare/socialcannon-vs-x-mcp.md)
- [Ayrshare API + MCP vs SocialCannon](https://www.anchorterminal.com/compare/ayrshare-vs-socialcannon.md)
- [Blotato vs SocialCannon](https://www.anchorterminal.com/compare/blotato-vs-socialcannon.md)
- [Buffer API + MCP vs SocialCannon](https://www.anchorterminal.com/compare/buffer-vs-socialcannon.md)
- [bundle.social vs SocialCannon](https://www.anchorterminal.com/compare/bundle-social-vs-socialcannon.md)
- [Metricool API + MCP vs SocialCannon](https://www.anchorterminal.com/compare/metricool-vs-socialcannon.md)
- [Mixpost API + MCP vs SocialCannon](https://www.anchorterminal.com/compare/mixpost-vs-socialcannon.md)
- [OneUp API + MCP vs SocialCannon](https://www.anchorterminal.com/compare/oneup-vs-socialcannon.md)
- [Post Bridge API + MCP vs SocialCannon](https://www.anchorterminal.com/compare/post-bridge-vs-socialcannon.md)
- [Postiz API + MCP vs SocialCannon](https://www.anchorterminal.com/compare/postiz-vs-socialcannon.md)
- [Publer API + MCP vs SocialCannon](https://www.anchorterminal.com/compare/publer-vs-socialcannon.md)
- [SocialCannon vs Typefully](https://www.anchorterminal.com/compare/socialcannon-vs-typefully.md)
- [SocialCannon vs Upload-Post API + MCP](https://www.anchorterminal.com/compare/socialcannon-vs-upload-post.md)

---

Query this catalogue directly over MCP: https://www.anchorterminal.com/mcp (Streamable HTTP, no key). How: https://www.anchorterminal.com/agents/#mcp