x402 List

x402 Protocol Service Directory

●

StableEmail

AI ✓ VERIFIED

verified until 2026-07-28

Pay-per-send email via micropayments. AWS SES backend. Supports subdomains, inboxes, and replies. USDC on Base or Solana.

Pay from $0.02 to $5.00 in USDC on Base / Solana, settled onchain via the x402 protocol, no signup, no API key needed.

UPTIME 24H 100% │ 7D 100% │ 30D 100%
BASE URL https://stableemail.dev │ ENDPOINTS 3 │ NETWORK Base / Solana │ ASSET USDC │ MEMBER SINCE 2026-02-05 │ MONITORED SINCE 2026-04-15

ASSESSMENT

updated 3h ago

Evidence-backed signals, not a single score. Click any chip for the proof. Measured values stay read-only; unknown is honest.

reliability 100%
uptime 24h
100%
uptime 7d
100%
uptime 30d
100%
uptime 90d
100%
response p95
388ms
avg response
357ms
total checks
7,356
compliance A (11/11)

11 of 11 x402 conformance checks pass. Full checklist below.

jump to compliance checklist

price $0.02 to $5.00 (p67 in AI)
price (min)
$0.02
price (max)
$5.00
category percentile (min)
p67 in AI
category percentile (max)
p91 in AI
endpoints / prices
3 / 3
model
tiered
stability
100%
risk clean

No deterministic risk flag. Risk fires only on an exact blocklist match, or a reserved-brand name with a mismatched verified payTo. Never from low uptime, a high price, or a model guess.

traction $27.42 30d · 64 buyers
volume 30d
$27.42
buyers 30d
64
settlements 30d
540
last settlement
2026-07-21
top buyer share
31% of 30d volume
trend 7d vs 30d
0.62x the 30d daily rate
networks
eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147dw2N9d

Conservative undercount: only USDC settlements via facilitators we measure are counted. A measured floor, not an estimate.

Top buyer share is a concentration signal, not part of the ranking score.

WHAT IT DOES

ai-derived

StableEmail provides email delivery services with managed inboxes, subdomain purchases, and email sending capabilities.

category
email-service
in
body
auth
none
emaildeliveryinbox-managementsubdomain

AI-generated summary. The measured data is never altered by it.

ENDPOINTS

Service endpoints with HTTP method, path, description, pricing, and network
METHOD PATH DESCRIPTION PRICE NETWORK ASSET
POST /api/inbox/buy Buy a managed inbox $1.00 Base/Solana USDC
POST /api/send Send email $0.02 Base/Solana USDC
POST /api/subdomain/buy Buy a subdomain $5.00 Base/Solana USDC
3 endpoints

REQUEST / RESPONSE EXAMPLE

An unpaid request to POST /api/inbox/buy returns HTTP 402 with the payment terms. Settle onchain via your facilitator, then retry with the X-Payment header.

// request
curl -i -X POST 'https://stableemail.dev/api/inbox/buy'
// 402 response (captured by monitor) · 3 payloads · click to expand 
[
  {
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xdb5aa553feeb2c3e3d03e8360b36fb0f7e480671",
        "amount": "1000000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      },
      {
        "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
        "extra": {
          "feePayer": "2wKupLR9q6wXYppw8Gr2NvWxKBUqm4PPJKkQfoxHDBg4"
        },
        "payTo": "HvBMG7ezcwDssxXP7DPJJsveyDnvUm2wNySBR5WF2XEY",
        "amount": "1000000",
        "scheme": "exact",
        "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://stableemail.dev/api/inbox/buy",
      "method": "POST",
      "mimeType": "application/json",
      "description": "Buy an inbox on stableemail.dev ($1, 30 days). forwardTo is optional — omit it to use as a programmatic mailbox via the messages API (retainMessages enabled automatically). Message content and attachments are retained for 90 days."
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {
              "username": "my-inbox"
            },
            "type": "http",
            "method": "POST",
            "bodyType": "json"
          }
        },
        "schema": {
          "type": "object",
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "required": [
            "input"
          ],
          "properties": {
            "input": {
              "type": "object",
              "required": [
                "type",
                "method",
                "bodyType",
                "body"
              ],
              "properties": {
                "body": {
                  "type": "object",
                  "$schema": "https://json-schema.org/draft/2020-12/schema",
                  "required": [
                    "username"
                  ],
                  "properties": {
                    "username": {
                      "type": "string",
                      "allOf": [
                        {
                          "pattern": "^[a-z0-9][a-z0-9-]{1,28}[a-z0-9]$"
                        },
                        {
                          "pattern": "^(?!.*--)"
                        }
                      ]
                    },
                    "forwardTo": {
                      "type": "string",
                      "format": "email",
                      "pattern": "^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"
                    }
                  },
                  "additionalProperties": false
                },
                "type": {
                  "type": "string",
                  "const": "http"
                },
                "method": {
                  "enum": [
                    "POST",
                    "PUT",
                    "PATCH"
                  ],
                  "type": "string"
                },
                "bodyType": {
                  "enum": [
                    "json",
                    "form-data",
                    "text"
                  ],
                  "type": "string"
                }
              },
              "additionalProperties": false
            }
          }
        }
      }
    },
    "x402Version": 2
  },
  {
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xdb5aa553feeb2c3e3d03e8360b36fb0f7e480671",
        "amount": "20000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      },
      {
        "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
        "extra": {
          "feePayer": "2wKupLR9q6wXYppw8Gr2NvWxKBUqm4PPJKkQfoxHDBg4"
        },
        "payTo": "HvBMG7ezcwDssxXP7DPJJsveyDnvUm2wNySBR5WF2XEY",
        "amount": "20000",
        "scheme": "exact",
        "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://stableemail.dev/api/send",
      "method": "POST",
      "mimeType": "application/json",
      "description": "Send an email from \"StableEmail\" <[email protected]> ($0.02)"
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {},
            "type": "http",
            "method": "POST",
            "bodyType": "json"
          }
        },
        "schema": {
          "type": "object",
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "required": [
            "input"
          ],
          "properties": {
            "input": {
              "type": "object",
              "required": [
                "type",
                "method",
                "bodyType",
                "body"
              ],
              "properties": {
                "body": {
                  "type": "object",
                  "$schema": "https://json-schema.org/draft/2020-12/schema",
                  "required": [
                    "to",
                    "subject"
                  ],
                  "properties": {
                    "cc": {
                      "type": "array",
                      "items": {
                        "type": "string",
                        "format": "email",
                        "pattern": "^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"
                      },
                      "maxItems": 50,
                      "minItems": 1
                    },
                    "to": {
                      "type": "array",
                      "items": {
                        "type": "string",
                        "format": "email",
                        "pattern": "^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"
                      },
                      "maxItems": 50,
                      "minItems": 1
                    },
                    "html": {
                      "type": "string",
                      "maxLength": 256000
                    },
                    "text": {
                      "type": "string",
                      "maxLength": 256000
                    },
                    "replyTo": {
                      "type": "string",
                      "format": "email",
                      "pattern": "^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"
                    },
                    "subject": {
                      "type": "string",
                      "maxLength": 998,
                      "minLength": 1
                    },
                    "attachments": {
                      "type": "array",
                      "items": {
                        "type": "object",
                        "required": [
                          "content",
                          "contentType",
                          "filename"
                        ],
                        "properties": {
                          "content": {
                            "type": "string",
                            "maxLength": 5000000
                          },
                          "filename": {
                            "type": "string",
                            "maxLength": 255,
                            "minLength": 1
                          },
                          "contentType": {
                            "type": "string",
                            "maxLength": 255,
                            "minLength": 1
                          }
                        },
                        "additionalProperties": false
                      },
                      "maxItems": 5
                    }
                  },
                  "additionalProperties": false
                },
                "type": {
                  "type": "string",
                  "const": "http"
                },
                "method": {
                  "enum": [
                    "POST",
                    "PUT",
                    "PATCH"
                  ],
                  "type": "string"
                },
                "bodyType": {
                  "enum": [
                    "json",
                    "form-data",
                    "text"
                  ],
                  "type": "string"
                }
              },
              "additionalProperties": false
            }
          }
        }
      }
    },
    "x402Version": 2
  },
  {
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xdb5aa553feeb2c3e3d03e8360b36fb0f7e480671",
        "amount": "5000000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      },
      {
        "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
        "extra": {
          "feePayer": "2wKupLR9q6wXYppw8Gr2NvWxKBUqm4PPJKkQfoxHDBg4"
        },
        "payTo": "HvBMG7ezcwDssxXP7DPJJsveyDnvUm2wNySBR5WF2XEY",
        "amount": "5000000",
        "scheme": "exact",
        "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://stableemail.dev/api/subdomain/buy",
      "method": "POST",
      "mimeType": "application/json",
      "description": "Purchase a custom email subdomain on stableemail.dev ($5)"
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {
              "subdomain": "my-brand"
            },
            "type": "http",
            "method": "POST",
            "bodyType": "json"
          }
        },
        "schema": {
          "type": "object",
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "required": [
            "input"
          ],
          "properties": {
            "input": {
              "type": "object",
              "required": [
                "type",
                "method",
                "bodyType",
                "body"
              ],
              "properties": {
                "body": {
                  "type": "object",
                  "$schema": "https://json-schema.org/draft/2020-12/schema",
                  "required": [
                    "subdomain"
                  ],
                  "properties": {
                    "subdomain": {
                      "type": "string",
                      "allOf": [
                        {
                          "pattern": "^[a-z0-9][a-z0-9-]{1,28}[a-z0-9]$"
                        },
                        {
                          "pattern": "^(?!.*--)"
                        }
                      ]
                    }
                  },
                  "additionalProperties": false
                },
                "type": {
                  "type": "string",
                  "const": "http"
                },
                "method": {
                  "enum": [
                    "POST",
                    "PUT",
                    "PATCH"
                  ],
                  "type": "string"
                },
                "bodyType": {
                  "enum": [
                    "json",
                    "form-data",
                    "text"
                  ],
                  "type": "string"
                }
              },
              "additionalProperties": false
            }
          }
        }
      }
    },
    "x402Version": 2
  }
]

UPTIME

07-15 · uptime 100.0% · 303ms avg07-16 · uptime 100.0% · 296ms avg07-17 · uptime 100.0% · 273ms avg07-18 · uptime 100.0% · 235ms avg07-19 · uptime 100.0% · 237ms avg07-20 · uptime 100.0% · 223ms avg07-21 · uptime 100.0% · 223ms avg07-1507-21
RESPONSE TIME
07-15 · 303ms avg07-15 · 303ms avg07-16 · 296ms avg07-16 · 296ms avg07-17 · 273ms avg07-17 · 273ms avg07-18 · 235ms avg07-18 · 235ms avg07-19 · 237ms avg07-19 · 237ms avg07-20 · 223ms avg07-20 · 223ms avg07-21 · 223ms avg07-21 · 223ms avg07-1507-21
7d UPTIME 100%
UPTIME 7D 100%
AVG RESP 352ms
TOTAL CHECKS 7,141

RECENT CHECKS

TIME STATUS RESP
● OK 429ms
● OK 211ms
● OK 177ms
● OK 272ms
● OK 255ms
● OK 113ms
● OK 247ms
● OK 303ms
● OK 299ms
● OK 414ms
● OK 259ms
● OK 106ms
● OK 95ms
● OK 194ms
● OK 273ms
● OK 135ms
● SLOW 750ms
● OK 186ms
18 of 7,141 checks

OVER TIME

All charts share the 7d window selected here. Every series is also served as JSON at /api/v1/services/stableemail/price, /scores, /volume and /buyers. On-chain volume and distinct buyers are measured over the service's settlement address and are a conservative undercount (only settlements that reach a measured facilitator are counted).

PRICE (captured 402, USD)
07-14 · $1.0007-21 · $1.00$1.0007-1407-21

Median across 3 endpoints. Use the selector to isolate one.

SUB-SCORES (uptime + x402 compliance)
07-14 uptime: 100.0% compliance: 92% checks07-15 uptime: 100.0% compliance: 92% checks07-16 uptime: 100.0% compliance: 92% checks07-17 uptime: 100.0% compliance: 100% checks07-18 uptime: 100.0% compliance: 100% checks07-19 uptime: 100.0% compliance: 100% checks07-20 uptime: 100.0% compliance: 100% checks07-21 uptime: 100.0% compliance: 100% checksuptimecompliance07-1407-21
VOLUME (on-chain settlement, USD)
07-14 · $0.2007-15 · $0.3007-16 · $0.1707-17 · $0.5007-18 · $107-19 · $0.1307-20 · $107-21 · $0.28peak $107-1407-21
DISTINCT BUYERS
07-14 · 7 buyers07-15 · 8 buyers07-16 · 6 buyers07-17 · 12 buyers07-18 · 8 buyers07-19 · 6 buyers07-20 · 9 buyers07-21 · 5 buyerspeak 12 buyers07-1407-21

COMPLIANCE

11/11 checks pass · grade A
  • 402 payload captured
  • accepts[] array present
  • payTo address recoverable
  • payTo at accepts[0].payTo (conformant shape)
  • payTo is a valid on-chain address
  • atomic price declared
  • atomic price in a sane range
  • asset (token) address declared
  • network resolves to CAIP-2
  • payment scheme declared
  • served over HTTPS

EMBED THIS BADGE

Show that StableEmail is monitored on x402-list. Paste this on your site or README, it links back to this live listing.

StableEmail listed on x402-list
status
StableEmail uptime on x402-list
live uptime
// HTML
<a href="https://x402-list.com/services/stableemail?utm_source=badge&utm_medium=referral&utm_campaign=embed">
  <img src="https://x402-list.com/badge/stableemail.svg" alt="StableEmail listed on x402-list" height="28">
</a>
// Markdown
[![StableEmail on x402-list](https://x402-list.com/badge/stableemail.svg)](https://x402-list.com/services/stableemail?utm_source=badge&utm_medium=referral&utm_campaign=embed)
// HTML · live uptime variant
<a href="https://x402-list.com/services/stableemail?utm_source=badge&utm_medium=referral&utm_campaign=embed">
  <img src="https://x402-list.com/badge/stableemail.svg?data=uptime" alt="StableEmail uptime on x402-list" height="28">
</a>

RUN THIS SERVICE?

Keep this listing accurate: propose changes to the name, description, website, category or add new endpoints to monitor. Ownership is verified with a domain proof and every change is reviewed manually; measured data stays read-only.

[ update this listing ]