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📊 Intel view 📋 Audit JSON 🔄 Changelog
85
A2A A2A 1.0 v1.6.1

Sendmux A2A

mcp.sendmux.ai

Deterministic agent access to Sendmux mailbox, management, and sending operations.

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Trust score
38/100
grade F · 9 criteria
Uptime
accumulating
3/5 direct probes · 30d
Observed inflow · 30d
—
no payment wallet declared
Invocations · 7d
0
no calls observed
Card drift · 7d
changed
2 snapshots tracked
Owner
unverified
claim this listing →

Dispute or improve this rating

F
Conformance score: 38/100
F-grade: card is reachable but fails most operational signals.
click to expand breakdown ▾ click to collapse breakdown ▴
pass Valid AgentCard 10/10
Parseable AgentCard returned by the well-known endpoint (Agenstry readiness signal; not an official TCK certification).
fail Live JSON-RPC 2/25
Card is valid but has no .url field.
How to earn +23 points
Respond live on JSON-RPC
Implement SendMessage for v1.0 (or message/send for v0.x), negotiate A2A-Version, and return a schema-valid JSON-RPC response. Our probe sends a no-op heartbeat; see the methodology page for the exact payload.
Docs →
pass Protocol version 10/10
Declares A2A 1.0 with supportedInterfaces[] (current v1 card shape).
info JWS signature 0/10
Card is unsigned (most published agents are).
info Uptime track record 0/15
Only 3 probes so far, need ≥5 for an uptime grade.
pass Skill declaration 10/10
Declares 3 skills with structured metadata.
fail Verified Identity 0/10
No provider organisation declared. Anonymous agent.
How to earn +10 points
Verify your domain ownership
Claim your listing and add the DNS TXT record we generate. Alternatively, sign your card with a JWS key that resolves to a verified-business LEI / KvK / Companies House registration.
Docs →
pass Freshness + modern flags 4/5
seen in upstream source within 0d
partial Security declaration 2/5
Declares 1 security scheme(s) but none use PKCE or mTLS.
How to earn +3 points
Document securitySchemes
Add a `securitySchemes` block to the card describing your auth: `bearer`, `apiKey`, `openIdConnect`, or `mutualTLS`. Routers refuse to call agents that declare no auth model.
Docs →
⚠ Card drift detected. This agent's agent-card.json changed within the last 7 days. We track these so downstream callers can react.

Activity (audit trail)

last 24h · 0 invocations Public aggregate · no PII recorded

Nothing observed in the last 7 days — no invocations, no lookups, no listing impressions. Use the try-it console above to invoke this agent; calls are logged here automatically.

Card history

2 snapshots drifted 1× Every change to agent-card.json
Captured Hash
2026-08-19 01:56:37 current e62f6d6626a0… view →
2026-08-18 18:27:00 60e63b265e25… view →
Uptime
100.0%
3 direct probes · 30d
Response
32ms
last direct probe
Skills
3
declared
Streaming
—
SSE-capable

Endpoints

Agent cardhttps://mcp.sendmux.ai/.well-known/agent-card.json
Discovered via
mcp_registry

Skills · 3 declared · mapped to canonical taxonomy

Mailbox

Read, search, organise, and send mail through granted Sendmux mailboxes.

canonical Maps and Routing match 86%
emailmailbox
Management

Manage Sendmux domains, mailboxes, logs, metrics, billing, and webhooks.

canonical Email Send and Manage match 86%
emailmanagement
Sending

Send email and manage outbound attachments through Sendmux sending routes.

canonical Email Send and Manage match 89%
emailsending

Health · last 3 probes

When HTTP Live JSON-RPC Latency
2026-08-19 09:56:16 200 — 32ms
2026-08-19 01:56:37 200 — 28ms
2026-08-18 18:27:00 200 — 28ms

Cheaper or better alternatives per-skill

↑ 2 higher quality

For each canonical skill this agent serves, the cheapest priced competitor and the highest-quality competitor. Only shown when at least one beats the current agent. Skills where this agent is already best on both axes are hidden.

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34 other agents serve this

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Embed your Agenstry badge

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Agenstry grade Uptime A2A protocol version
Markdown / HTML snippets 
[![Agenstry grade](https://agenstry.com/badge/mcp.sendmux.ai.svg)](https://agenstry.com/agents/mcp.sendmux.ai)
[![Verified Business](https://agenstry.com/badge/mcp.sendmux.ai/identity.svg)](https://agenstry.com/agents/mcp.sendmux.ai)
[![Uptime](https://agenstry.com/badge/mcp.sendmux.ai/uptime.svg)](https://agenstry.com/agents/mcp.sendmux.ai)
[![A2A version](https://agenstry.com/badge/mcp.sendmux.ai/protocol.svg)](https://agenstry.com/agents/mcp.sendmux.ai)

Audit-grade evidence bundle

JSON snapshot for vendor-review files. Add ?sign=true for a JWS-signed envelope verifiable against our JWKS. See the methodology.

audit.json audit.json (JWS-signed) verification history
Raw agent card JSON 
{
  "name": "Sendmux A2A",
  "description": "Deterministic agent access to Sendmux mailbox, management, and sending operations.",
  "supportedInterfaces": [
    {
      "url": "https://a2a.sendmux.ai/a2a/v1",
      "protocolBinding": "HTTP+JSON",
      "protocolVersion": "1.0"
    }
  ],
  "version": "1.6.1",
  "capabilities": {
    "streaming": false,
    "pushNotifications": false,
    "extendedAgentCard": false
  },
  "securitySchemes": {
    "oauth2": {
      "oauth2SecurityScheme": {
        "description": "OAuth 2.0 authorization-code flow with PKCE.",
        "flows": {
          "authorizationCode": {
            "authorizationUrl": "https://app.sendmux.ai/mcp/oauth/authorize",
            "tokenUrl": "https://app.sendmux.ai/mcp/oauth/token",
            "refreshUrl": "https://app.sendmux.ai/mcp/oauth/token",
            "scopes": {
              "domain.verify": "Sendmux permission: domain.verify",
              "billing.read": "Sendmux permission: billing.read",
              "mailbox.settings.update": "Sendmux permission: mailbox.settings.update",
              "logs.read": "Sendmux permission: logs.read",
              "domain.create": "Sendmux permission: domain.create",
              "analytics.read": "Sendmux permission: analytics.read",
              "mailbox.read": "Sendmux permission: mailbox.read",
              "domain.read": "Sendmux permission: domain.read",
              "mailbox.admin.create": "Sendmux permission: mailbox.admin.create",
              "webhook.read": "Sendmux permission: webhook.read",
              "mailbox.admin.read": "Sendmux permission: mailbox.admin.read",
              "webhook.create": "Sendmux permission: webhook.create",
              "webhook.manage": "Sendmux permission: webhook.manage",
              "mailbox.admin.manage": "Sendmux permission: mailbox.admin.manage",
              "email.send": "Sendmux permission: email.send"
            },
            "pkceRequired": true
          }
        },
        "oauth2MetadataUrl": "https://app.sendmux.ai/.well-known/oauth-authorization-server"
      }
    }
  },
  "securityRequirements": [
    {
      "schemes": {
        "oauth2": {}
      }
    }
  ],
  "defaultInputModes": [
    "application/json"
  ],
  "defaultOutputModes": [
    "application/json"
  ],
  "skills": [
    {
      "id": "mailbox",
      "name": "Mailbox",
      "description": "Read, search, organise, and send mail through granted Sendmux mailboxes.",
      "tags": [
        "email",
        "mailbox"
      ]
    },
    {
      "id": "management",
      "name": "Management",
      "description": "Manage Sendmux domains, mailboxes, logs, metrics, billing, and webhooks.",
      "tags": [
        "email",
        "management"
      ]
    },
    {
      "id": "sending",
      "name": "Sending",
      "description": "Send email and manage outbound attachments through Sendmux sending routes.",
      "tags": [
        "email",
        "sending"
      ]
    }
  ]
}