StableEmail

https://stableemail.dev 79% (83/105)

Compliance Checks

✓ All paid ops declare 402 response MUST 10pt

✗ All x-payment-info valid MUST 10pt

✓ Challenge has Cache-Control: no-store MUST 5pt

✗ Challenge digest on POST SHOULD 3pt

✓ Challenge has expires SHOULD 3pt

✗ Challenge has Problem Details SHOULD 2pt

✓ Challenge has required params MUST 5pt

✓ Challenge has WWW-Authenticate MUST 5pt

✓ Challenge returns 402 MUST 10pt

✓ Correct Content-Type MUST 5pt

✓ Has Cache-Control on discovery SHOULD 5pt

✓ Has input schemas SHOULD 5pt

✗ Has llms.txt SHOULD 5pt

✓ Has /openapi.json at root MUST 10pt

✓ Has required top-level fields MUST 10pt

✓ Served over HTTPS MUST 10pt

✗ Uses standard categories SHOULD 2pt

1 issue

POST endpoint challenge missing digest parameter (SHOULD per spec)

Paid Operations (13)

POST /api/subdomain/buy dynamic

Purchase a custom email subdomain on stableemail.dev ($5)

Amount: map[amount:5 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Non-standard x-payment-info fields: price: map[amount:5 currency:USD mode:fixed] protocols: [map[x402:map[]] map[mpp:map[currency:0x20c0000000000000000000000000000000000001 intent:charge method:tempo]]]

Input Schema

Field	Type	Required	Description
subdomain	string	Yes

POST /api/send dynamic

Send an email from "StableEmail" <relay@stableemail.dev> ($0.02)

Amount: map[amount:0.02 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Non-standard x-payment-info fields: price: map[amount:0.02 currency:USD mode:fixed] protocols: [map[x402:map[]] map[mpp:map[currency:0x20c0000000000000000000000000000000000001 intent:charge method:tempo]]]

Input Schema

Field	Type	Required
attachments	array	No
html	string	No
replyTo	string (email)	No
subject	string	Yes
text	string	No
to	array	Yes

POST /api/subdomain/inbox/messages dynamic

List messages in a subdomain inbox ($0.001)

Amount: map[amount:0.001 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Non-standard x-payment-info fields: price: map[amount:0.001 currency:USD mode:fixed] protocols: [map[x402:map[]] map[mpp:map[currency:0x20c0000000000000000000000000000000000001 intent:charge method:tempo]]]

Input Schema

Field	Type	Required	Description
cursor	string	No
limit	integer	No	default: `20`
localPart	string	Yes
subdomain	string	Yes

POST /api/inbox/messages dynamic

List messages in your inbox ($0.001)

Amount: map[amount:0.001 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Input Schema

Field	Type	Required	Description
cursor	string	No
limit	integer	No	default: `20`
username	string	Yes

POST /api/subdomain/send dynamic

Send email from your custom subdomain on stableemail.dev ($0.005)

Amount: map[amount:0.005 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Non-standard x-payment-info fields: price: map[amount:0.005 currency:USD mode:fixed] protocols: [map[x402:map[]] map[mpp:map[currency:0x20c0000000000000000000000000000000000001 intent:charge method:tempo]]]

Input Schema

Field	Type	Required
attachments	array	No
from	string (email)	Yes
html	string	No
replyTo	string (email)	No
subject	string	Yes
text	string	No
to	array	Yes

POST /api/inbox/buy dynamic

Buy an inbox on stableemail.dev ($1, 30 days). forwardTo is optional — omit it to use as a programmatic mailbox via the messages API (retainMessages enabled automatically). Message content and attachments are retained for 90 days.

Amount: map[amount:1 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Non-standard x-payment-info fields: price: map[amount:1 currency:USD mode:fixed] protocols: [map[x402:map[]] map[mpp:map[currency:0x20c0000000000000000000000000000000000001 intent:charge method:tempo]]]

Input Schema

Field	Type	Required	Description
forwardTo	string (email)	No
username	string	Yes

POST /api/inbox/send dynamic

Send email from your forwarding inbox on stableemail.dev ($0.005)

Amount: map[amount:0.005 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Input Schema

Field	Type	Required
attachments	array	No
html	string	No
replyTo	string (email)	No
subject	string	Yes
text	string	No
to	array	Yes
username	string	Yes

POST /api/inbox/topup dynamic

Top up a forwarding inbox for 30 days ($1)

Amount: map[amount:1 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Input Schema

Field	Type	Required	Description
username	string	Yes

POST /api/inbox/topup/quarter dynamic

Top up a forwarding inbox for 90 days ($2.50, save 17%)

Amount: map[amount:2.5 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Non-standard x-payment-info fields: price: map[amount:2.5 currency:USD mode:fixed] protocols: [map[x402:map[]] map[mpp:map[currency:0x20c0000000000000000000000000000000000001 intent:charge method:tempo]]]

Input Schema

Field	Type	Required	Description
username	string	Yes

POST /api/inbox/topup/year dynamic

Top up a forwarding inbox for 365 days ($8, save 34%)

Amount: map[amount:8 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Non-standard x-payment-info fields: price: map[amount:8 currency:USD mode:fixed] protocols: [map[x402:map[]] map[mpp:map[currency:0x20c0000000000000000000000000000000000001 intent:charge method:tempo]]]

Input Schema

Field	Type	Required	Description
username	string	Yes

POST /api/inbox/messages/read dynamic

Read a single inbox message ($0.001). Returns text, HTML, and attachment download URLs (1hr expiry). Message content available for 90 days from receipt.

Amount: map[amount:0.001 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Input Schema

Field	Type	Required	Description
messageId	string	Yes

POST /api/subdomain/inbox/create dynamic

Create an inbox on your subdomain ($0.25). Max 100 inboxes, 500 messages each. Message content and attachments retained for 90 days.

Amount: map[amount:0.25 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Non-standard x-payment-info fields: price: map[amount:0.25 currency:USD mode:fixed] protocols: [map[x402:map[]] map[mpp:map[currency:0x20c0000000000000000000000000000000000001 intent:charge method:tempo]]]

Input Schema

Field	Type	Required
forwardTo	string (email)	No
localPart	string	Yes
subdomain	string	Yes

POST /api/subdomain/inbox/messages/read dynamic

Read a single subdomain inbox message ($0.001). Returns text, HTML, and attachment download URLs (1hr expiry). Message content available for 90 days from receipt.

Amount: map[amount:0.001 currency:USD mode:fixed]
Currency: -
Method
Intent: -
402 Declared: Yes

Input Schema

Field	Type	Required	Description
messageId	string	Yes

Payment Methods

Methods: tempo (from challenge)
Intents: charge (from challenge)
Currencies (discovery): -
Currency (challenge): USDC.e on Tempo (Tempo)
Multiple Challenges: No

Recipients

0x7bAfA37A71254E496e7E47a8a139E719683a34c2

Per-endpoint breakdown

POST /api/inbox/buy: 0x7bAfA37A71254E496e7E47a8a139E719683a34c2
POST /api/inbox/messages: 0x7bAfA37A71254E496e7E47a8a139E719683a34c2
POST /api/send: 0x7bAfA37A71254E496e7E47a8a139E719683a34c2
POST /api/subdomain/buy: 0x7bAfA37A71254E496e7E47a8a139E719683a34c2
POST /api/subdomain/inbox/messages: 0x7bAfA37A71254E496e7E47a8a139E719683a34c2
POST /api/subdomain/send: 0x7bAfA37A71254E496e7E47a8a139E719683a34c2

Security

TLS Version: TLSv1.3
Challenge ID Unique: Yes
Challenge ID Length: 43
Digest Binding: -

Uptime

Discovery: Reachable (333ms)
Challenge: Reachable (623ms)
Last Checked: 2026-04-07T18:32:37Z

Schema Completeness

Paid Operations: 13
With Input Schema: 13
With Description: 13

Documentation

Homepage: -
API Reference: -
llms.txt: -

Discovery

OpenAPI URL: https://stableemail.dev/openapi.json
OpenAPI Version: 3.1.0
Service Version: 0.1.0
Document Size: 47121 bytes
Document Hash: 2590c3e96ccbc2dab11b3dbe9c7d25e93d2fc5a51d610872e0c53acece3594e6

Version History (2 snapshots)

2026-04-07

document hash changed (no semantic differences detected)

2026-04-07

document hash changed (no semantic differences detected)

2026-04-07

document hash changed (no semantic differences detected)

2026-04-07

document hash changed (no semantic differences detected)

2026-04-07

document hash changed (no semantic differences detected)

2026-04-07

document hash changed (no semantic differences detected)

2026-04-07

document hash changed (no semantic differences detected)

2026-04-06

document hash changed (no semantic differences detected)

2026-04-06

price changed on POST /api/inbox/buy: {'mode': 'fixed', 'currency': 'USD', 'amount': '1'} → None
price changed on POST /api/inbox/messages: {'mode': 'fixed', 'currency': 'USD', 'amount': '0.001'} → None
price changed on POST /api/inbox/messages/read: {'mode': 'fixed', 'currency': 'USD', 'amount': '0.001'} → None
price changed on POST /api/inbox/send: {'mode': 'fixed', 'currency': 'USD', 'amount': '0.005'} → None
price changed on POST /api/inbox/topup: {'mode': 'fixed', 'currency': 'USD', 'amount': '1'} → None
price changed on POST /api/inbox/topup/quarter: {'mode': 'fixed', 'currency': 'USD', 'amount': '2.5'} → None
price changed on POST /api/inbox/topup/year: {'mode': 'fixed', 'currency': 'USD', 'amount': '8'} → None
price changed on POST /api/send: {'mode': 'fixed', 'currency': 'USD', 'amount': '0.02'} → None
price changed on POST /api/subdomain/buy: {'mode': 'fixed', 'currency': 'USD', 'amount': '5'} → None
price changed on POST /api/subdomain/inbox/create: {'mode': 'fixed', 'currency': 'USD', 'amount': '0.25'} → None
price changed on POST /api/subdomain/inbox/messages: {'mode': 'fixed', 'currency': 'USD', 'amount': '0.001'} → None
price changed on POST /api/subdomain/inbox/messages/read: {'mode': 'fixed', 'currency': 'USD', 'amount': '0.001'} → None
price changed on POST /api/subdomain/send: {'mode': 'fixed', 'currency': 'USD', 'amount': '0.005'} → None

Scan snapshots

Date	Grade	Score	Response	Status
2026-04-06	B	79%	305ms	Up
2026-04-07	B	79%	493ms	Up