# Bot403 (bot403.com)

Blocks spam form submissions by having the browser solve a proof-of-work challenge that the server verifies in one call.

- Atlas card: https://inite.ai/en/atlas/bot403.com
- Site: https://bot403.com
- For: site owners and developers whose HTML forms get spam and who want no captcha
- Categories: productivity
- Use not measured/100 · alive 100/100

## Used for

- add invisible bot checks to contact forms
- verify form submissions on the server before processing
- let an AI assistant install protection into a project

## Price

- from 2 EUR/month, free plan (read 2026-10-29 on https://bot403.com/pricing)

## For developers

- OpenAPI: https://bot403.com/openapi.json (18 paths)
- MCP server: com.bot403/bot403 (namespace; auth on 2026-10-29)
- Status page: https://bot403.com/status
- Read 2026-10-29

## MCP server, measured daily

Server: https://bot403.com/mcp, checked every day since 2026-10-29 (5 checks).

- Answered: measuring, 5 daily checks so far
- Median first answer: 537 ms
- Sign-in: OAuth (the client signs the user in)
- Method: https://inite.ai/en/atlas/mcp/report

## Your data

- Certifications stated: gdpr
- Read 2026-10-29

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Source: INITE Atlas, https://inite.ai/en/atlas/bot403.com. JSON: https://inite.ai/api/atlas/bot403.com. MCP: https://inite.ai/api/mcp (atlas_lookup).