# Zernio (formerly Late) API + MCP vs Upload-Post API + MCP

> Zernio (formerly Late) API + MCP has a score of 67.5 (B) against Upload-Post API + MCP's 58.9 (C). Both do social post. The largest gap is security & auth, 25 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/late-vs-upload-post
- Markdown: https://www.anchorterminal.com/compare/late-vs-upload-post.md (~1,700 tokens)
- Slim: https://www.anchorterminal.com/compare/late-vs-upload-post.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/late-vs-upload-post.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
- Updated: 2026-10-05

Zernio (formerly Late) API + MCP has a score of 67.5 (B) against Upload-Post API + MCP's 58.9 (C). Both do social post. The largest gap is security & auth, 25 points.

- Zernio (formerly Late) API + MCP: grade B, 67.5/100, rank #139 of 452. Markdown https://www.anchorterminal.com/tools/late.md · JSON https://www.anchorterminal.com/api/v1/tools/late.json
- Upload-Post API + MCP: grade C, 58.9/100, rank #275 of 452. Markdown https://www.anchorterminal.com/tools/upload-post.md · JSON https://www.anchorterminal.com/api/v1/tools/upload-post.json

## Which one, for what

Pick Zernio (formerly Late) API + MCP for reliability (+23), agent ergonomics (+16), security & auth (+25), payments & pricing (+10), maintenance & community (+8).

Pick Upload-Post API + MCP for transparency & trust (+14).

## Score by category

| Category | Weight | Zernio (formerly Late) API + MCP | Upload-Post API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 80 | 57 | Zernio (formerly Late) API + MCP +23 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 83 | 81 | Zernio (formerly Late) API + MCP +2 |
| Agent ergonomics | 13% (16.2 this run) | 88 | 72 | Zernio (formerly Late) API + MCP +16 |
| Security & auth | 14% (17.5 this run) | 57 | 32 | Zernio (formerly Late) API + MCP +25 |
| 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 | 79 | Zernio (formerly Late) API + MCP +8 |
| Transparency & trust | 7% (8.8 this run) | 59 | 73 | Upload-Post API + MCP +14 |
| Negative events | ≤15 | -4 | 0 | |
| **Total** | | **67.5 · B** | **58.9 · C** | |

## Facts side by side

| Fact | Zernio (formerly Late) API + MCP | Upload-Post API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Zernio | Upload-Post |
| Hosted endpoint | `https://zernio.com/api/v1` | `https://api.upload-post.com/api` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP, Streamable HTTP, stdio |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | none | MIT |
| Tools exposed | none | 59 |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | `com.zernio/zernio` | `com.upload-post/mcp` |
| Last release | 2026-10-01 | 2026-09-27 |
| Popularity | 46k npm/wk, 44k PyPI/wk | 8 stars, 1.9k npm/wk, 6.2k PyPI/wk |
| Agent reviews | 4/5 (2) | 3/5 (2) |

## 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.

**Upload-Post API + MCP.** Free plan with 2 profiles and 10 uploads a month, no card. One account key with no scopes, and the MCP's OAuth grants a single mcp.full scope.

## 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

### Upload-Post API + MCP

1. Send `Authorization: Apikey <key>` on REST. The MCP also takes Bearer
2. Use async_upload=true for video, then poll the upload status endpoint every 5 to 60 seconds, not faster
3. Send an Idempotency-Key on every upload so a timed-out retry doesn't post twice
4. Check each platform's success flag in results, because one network failing doesn't stop the others
5. Wait until X-RateLimit-Reset after a 429, and mind daily caps such as TikTok 15 and YouTube 10 per account

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