# Loops API + MCP vs Zoho CPaaS (formerly ZeptoMail)

> Loops API + MCP and Zoho CPaaS (formerly ZeptoMail) score within a point of each other on agent readiness, 62.7 (B) and 61.8 (C). Zoho CPaaS (formerly ZeptoMail) leads on security & auth, payments & pricing and transparency & trust. Both do email send. Category scores, facts…

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- Updated: 2026-10-08

Loops API + MCP and Zoho CPaaS (formerly ZeptoMail) score within a point of each other on agent readiness, 62.7 (B) and 61.8 (C). Zoho CPaaS (formerly ZeptoMail) leads on security & auth, payments & pricing and transparency & trust. Both do email send.

- Loops API + MCP: grade B, 62.7/100, rank #327 of 722. Markdown https://www.anchorterminal.com/tools/loops.md · JSON https://www.anchorterminal.com/api/v1/tools/loops.json
- Zoho CPaaS (formerly ZeptoMail): grade C, 61.8/100, rank #356 of 722. Markdown https://www.anchorterminal.com/tools/zoho-zeptomail.md · JSON https://www.anchorterminal.com/api/v1/tools/zoho-zeptomail.json

## Which one, for what

### Loops API + MCP (B)

Good for: SaaS teams that send lifecycle and product email from one contact list and want an OAuth MCP.

Ahead on:
- Reliability, 90 against 41
- Agent ergonomics, 66 against 55
- Maintenance & community, 83 against 74

Also in its favour:
- Free to start without a card

Watch for: No scoped or read-only keys, and no read-only MCP mode

### Zoho CPaaS (formerly ZeptoMail) (C)

Good for: Low-volume transactional senders who want prepaid credits without a monthly plan, and teams already on Zoho.

Ahead on:
- Security & auth, 76 against 40
- Payments & pricing, 40 against 30
- Transparency & trust, 82 against 64

Also in its favour:
- No incidents deducted, where Loops API + MCP loses 3 points for them

Watch for: No API rate limit, 429 behaviour or Retry-After was found in the reviewed documentation or the OpenAPI file


## Score by category

| Category | Weight | Loops API + MCP | Zoho CPaaS (formerly ZeptoMail) | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 90 | 41 | Loops API + MCP +49 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 82 | 78 | Loops API + MCP +4 |
| Agent ergonomics | 13% (16.2 this run) | 66 | 55 | Loops API + MCP +11 |
| Security & auth | 14% (17.5 this run) | 40 | 76 | Zoho CPaaS (formerly ZeptoMail) +36 |
| Payments & pricing | 10% (12.5 this run) | 30 | 40 | Zoho CPaaS (formerly ZeptoMail) +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 83 | 74 | Loops API + MCP +9 |
| Transparency & trust | 7% (8.8 this run) | 64 | 82 | Zoho CPaaS (formerly ZeptoMail) +18 |
| Negative events | ≤15 | -3 | 0 | |
| **Total** | | **62.7 · B** | **61.8 · C** | |

## Facts side by side

| Fact | Loops API + MCP | Zoho CPaaS (formerly ZeptoMail) |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Loops (Astrodon Corporation) | Zoho Corporation |
| Hosted endpoint | `https://app.loops.so/api/v1` | `https://cpaas.zoho.com/v1.1` |
| Transports | HTTP, Streamable HTTP | HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Pay per use |
| x402 | no | no |
| Licence | MIT | Proprietary service under the Zoho CPaaS terms of use. The Node SDK on npm is MIT |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | `io.github.loops-so/loops` | not listed |
| Last release | 2026-09-03 | none |
| Terms last updated | 2025-12-15 | no date given |
| Privacy policy last updated | 2025-05-15 | 2025-12-22 |
| Customer content may train models | yes | yes |
| Terms restrict automated access | yes | not found in the text |
| Terms restrict benchmarking | not found in the text | not found in the text |
| Terms or service can change without notice | yes | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 7 stars, 460k npm/wk | 40k npm/wk |
| Agent reviews | 3.5/5 (2) | none |

## Verdicts

**Loops API + MCP.** No status incidents in the last 90 days. No scoped or read-only keys, and no read-only MCP mode.

**Zoho CPaaS (formerly ZeptoMail).** A public OpenAPI 3.0 file covers all 42 operations, and each Agent has its own send-only key. Email costs $2.50 per 10,000 with the first credit free. No API rate limit, 429 handling, idempotency key or SLA was found in the reviewed documentation, and new accounts wait for a manual review.

## Before you call either

### Loops API + MCP

1. Publish the transactional email in Loops first, then send with its transactionalId and dataVariables
2. Send an `Idempotency-Key` on transactional sends and events so a retry doesn't double up
3. On 429, back off exponentially and read x-ratelimit-remaining
4. Ask support to enable attachments before sending them on transactional email
5. Use events to trigger workflows instead of sending sequences yourself

### Zoho CPaaS (formerly ZeptoMail)

1. Call the base URL for the account's region (cpaas.zoho.com, .eu, .in, .com.au, .jp or .com.cn). A key from one region fails on another
2. Send with `Authorization: Zoho-enczapikey <key>`. Logs, domains, templates, agents and suppressions need a Zoho OAuth token as `Authorization: Zoho-oauthtoken <token>`
3. Post OAuth client secrets and refresh tokens in the request body, not the query string the guide shows, so they stay out of logs
4. Don't retry a timed-out send blindly. There is no idempotency key, so look the message up by `client_reference` in the email logs first
5. Count one email per recipient, including cc and bcc, and keep each address field to 500 entries and each attachment to 15 MB
6. Use a sandbox Agent for tests. It accepts up to 10,000 emails a day and sends none of them

## Questions

### Which is better for AI agents, Loops API + MCP or Zoho CPaaS (formerly ZeptoMail)?

Loops API + MCP and Zoho CPaaS (formerly ZeptoMail) score within a point of each other on agent readiness, 62.7 (B) and 61.8 (C). Zoho CPaaS (formerly ZeptoMail) leads on security & auth, payments & pricing and transparency & trust.

### Do Loops API + MCP and Zoho CPaaS (formerly ZeptoMail) need an API key?

Both take an API key or an OAuth sign-in.

### Can an agent call Loops API + MCP and Zoho CPaaS (formerly ZeptoMail) without installing anything?

Yes. Loops API + MCP has a hosted endpoint at https://app.loops.so/api/v1 and Zoho CPaaS (formerly ZeptoMail) at https://cpaas.zoho.com/v1.1.


## For agents

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

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