37signals.com

Observed 2026-07-18T13:21:38.067207100+00:00 (37m ago). Every field below was attested with an Ed25519 signature at scan time.

Up right now

Runs onCloudflare

Email byMailchimp

Secured byGoogle Trust Services

Registered withCloudflare, Inc.

Also usesZoomAtlassianGoogle Search ConsoleStripe

tranco_40k

Every line above is a signed observation. Check the math at the bottom of the page.

INFRASTRUCTURE MAPwhat 37signals.com actually stands on - every host below is a signed observation

37signals.com

A / AAAA

104.18.0.135104.18.1.135

Cloudflareserves the site

merlin.ns.cloudflare.comserena.ns.cloudflare.com

cloudflare.comanswers its DNS

work-mx.app.hey.com

Mailchimpreceives its email

TLS

37signals.com

Google Trust Servicesissued its certificate

DNS Records

A 2

104.18.0.135
104.18.1.135

MX 1

10work-mx.app.hey.com

TXT 12

8x2rys9qrtmrt08s01k2dhf220y0bc3h
ZOOM_verify_3PsRA01tPEqbRQuZq0ovDX
anthropic-domain-verification-2ned89=7e1u02UWpXxRVFbqXvTepQODa
apple-domain-verification=fZq9u43pq901FVrX
atlassian-domain-verification=jDcnbDUp4Eqr8vcG6rwzJC/AiL4ryyQCoTDiAKjKnP7rzlvnA4akV4QxvGnUaMS8
google-site-verification=75SnvFixCmuTIw1yttct06G6Mk7vGOqJDKqVd4sD66g
google-site-verification=vPyWJnzga2ciedbmL9z3PaMMS7gMZba_d4KE-GXzcUI
hey-verification:wvrWxEPH2vgJ5hJp8cjdWfZx
openai-domain-verification=dv-brKIWqu5JEkAoXYjfCz66ucV
stripe-verification=F970494BA4495175BB0BBBBBB611C2410B599753DB459B0B27676C72D5A688A6

NS 2

merlin.ns.cloudflare.com
serena.ns.cloudflare.com

SOA 1

merlin.ns.cloudflare.com dns.cloudflare.com

CAA 13

iodef "mailto:sysadmins@37signals.com"
issue "amazon.com"
issue "comodoca.com"
issue "digicert.com; cansignhttpexchanges=yes"
issue "globalsign.com"
issue "letsencrypt.org"
issue "pki.goog; cansignhttpexchanges=yes"
issue "ssl.com"
issuewild "comodoca.com"
issuewild "digicert.com; cansignhttpexchanges=yes"

TLS Certificates (3)

Common Name	Issuer	Expires
`37signals.com`	C=US, O=Google Trust Services, CN=WE1	Thu, 20 Aug 2026 06:45:19 +0000
`WE1`	C=US, O=Google Trust Services LLC, CN=GTS Root R4	Tue, 20 Feb 2029 14:00:00 +0000
`GTS Root R4`	C=BE, O=GlobalSign nv-sa, 2.5.4.11=Root CA, CN=GlobalSign Root CA	Fri, 28 Jan 2028 00:00:42 +0000

Subdomains (0)

None observed.

The proof

Signed at scan time. Check the math yourself. Every line above is part of one signed observation. Re-hash it and check the Ed25519 signature in your own browser; nothing leaves your machine.

Verify this receipt

Put the receipt on your own site. A live badge showing what DomainDrift observes and signs for 37signals.com. It updates itself. It attests a signed observation - not that the site is safe.

<a href="https://domaindrift.io/t/37signals.com">
  <img src="https://domaindrift.io/badge/37signals.com.svg"
       width="300" height="64" alt="DomainDrift signed observations for 37signals.com">
</a>

Ed25519 Receipt

Receipt ID: 030475d6-fa0c-41a7-b38e-ebaf5f36cf67
Output Hash: 068280f7af7c90f8b56e2999d98c98eedeefb5a75502f2e50337f0c59a643bc5
Signature: ed25519:09041880046aaaec11463ec15cf858dfcab17ec6d2e5aa86cab311bbdd0aff1e47277ee81570919d32501d5fe10a11022e84bdfd30c06857e3bf9988523ddd09
Public Key: ed25519:178c3bd0f57d9d64b83cc4630753381e1a465005a2bbba3d032371f24af0bfd8
Parent: (genesis)
Plane: fast

Verify this in your browser

Permalink: https://domaindrift.io/t/37signals.com