# Zernio (formerly Late) API + MCP vs OneUp API + MCP

> Zernio (formerly Late) API + MCP has a score of 67.5 (B) against OneUp API + MCP's 24.8 (F). Both do social post. The largest gap is reliability, 62 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/late-vs-oneup
- Markdown: https://www.anchorterminal.com/compare/late-vs-oneup.md (~1,700 tokens)
- Slim: https://www.anchorterminal.com/compare/late-vs-oneup.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/late-vs-oneup.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 OneUp API + MCP's 24.8 (F). Both do social post. The largest gap is reliability, 62 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
- OneUp API + MCP: grade F, 24.8/100, rank #445 of 452. Markdown https://www.anchorterminal.com/tools/oneup.md · JSON https://www.anchorterminal.com/api/v1/tools/oneup.json

## Which one, for what

Pick Zernio (formerly Late) API + MCP for reliability (+62), schema & documentation (+56), agent ergonomics (+57), security & auth (+40), payments & pricing (+30), maintenance & community (+44), transparency & trust (+16).

Pick OneUp API + MCP for nothing in particular (no category where it leads by five points or more).

## Score by category

| Category | Weight | Zernio (formerly Late) API + MCP | OneUp API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 80 | 18 | Zernio (formerly Late) API + MCP +62 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 83 | 27 | Zernio (formerly Late) API + MCP +56 |
| Agent ergonomics | 13% (16.2 this run) | 88 | 31 | Zernio (formerly Late) API + MCP +57 |
| Security & auth | 14% (17.5 this run) | 57 | 17 | Zernio (formerly Late) API + MCP +40 |
| Payments & pricing | 10% (12.5 this run) | 40 | 10 | Zernio (formerly Late) API + MCP +30 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 87 | 43 | Zernio (formerly Late) API + MCP +44 |
| Transparency & trust | 7% (8.8 this run) | 59 | 43 | Zernio (formerly Late) API + MCP +16 |
| Negative events | ≤15 | -4 | 0 | |
| **Total** | | **67.5 · B** | **24.8 · F** | |

## Facts side by side

| Fact | Zernio (formerly Late) API + MCP | OneUp API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Zernio | OneUp |
| Hosted endpoint | `https://zernio.com/api/v1` | `https://www.oneupapp.io/api` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP, Streamable HTTP |
| Auth | OAuth or key | API key |
| Pricing | Freemium | Paid |
| x402 | no | no |
| Licence | none | none |
| Tools exposed | none | 50 |
| 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 | no |
| MCP registry | `com.zernio/zernio` | not listed |
| Last release | 2026-10-01 | none |
| Popularity | 46k npm/wk, 44k PyPI/wk | none |
| Agent reviews | 4/5 (2) | 1.5/5 (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.

**OneUp API + MCP.** API and MCP on every plan from $25 a month ($15 billed yearly). API key in the query string on REST and in the MCP URL, with no scopes.

## 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

### OneUp API + MCP

1. Call listcategory, then listcategoryaccount, then schedule. Pass social_network_id as ALL to post to every account in a category
2. Keep the ?apiKey= URLs out of logs and shared configs, and regenerate the key on the API Access page if one leaks
3. Set requireApproval or isDraftPost true when a person should review before anything goes out
4. Page through lists with start, 50 posts at a time
5. Give dates as YYYY-MM-DD HH:MM with no timezone field, so confirm the account timezone first

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