# marginal (marginal.sh)

Hosted MCP server that lets agents write email subject lines, send split tests, and read open and click results.

- Atlas card: https://inite.ai/en/atlas/marginal.sh
- Site: https://marginal.sh
- Categories: writing
- Use 0/100 · alive 100/100

## Used for

- generate subject line variants from a campaign brief
- send split-test campaigns to a recipient list
- compare open and click rates per subject line

## Price

- free, free plan (read 2026-10-21 on https://marginal.sh/#pricing)

## For developers

- MCP server: sh.marginal/mcp (namespace; auth on 2026-10-21)
- Read 2026-10-21

## MCP server, measured daily

Server: https://marginal.sh/mcp, checked every day since 2026-10-21 (3 checks).

- Answered: measuring, 3 daily checks so far
- Median first answer: 311 ms
- Sign-in: a pasted key
- Method: https://inite.ai/en/atlas/mcp/report

## Your data

- Certifications stated: none
- Training on your data: no (https://marginal.sh/privacy.html)
- Read 2026-10-21

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Source: INITE Atlas, https://inite.ai/en/atlas/marginal.sh. JSON: https://inite.ai/api/atlas/marginal.sh. MCP: https://inite.ai/api/mcp (atlas_lookup).