POST/inbox/messages
Send or reply via connected Gmail (irreversible). 0 credits. Optional Idempotency-Key. Rate class: inbox_send (default 10/min).
Request
POST /inbox/messages
X-API-Key: sk_live_...
Content-Type: application/json
{
"campaignId": "search-xyz",
"leadId": "lead_abc",
"text": "Hi Jane — quick question about Acme Dental.",
"subject": "Quick question",
"accountId": "acc_abc"
}
| Field | Required | Notes |
|---|---|---|
campaignId | Yes | |
leadId | Yes | |
text | Yes | Non-empty; max 8000 |
subject | No | Max 500 |
accountId | No | Prefer specific Gmail account |
Response
{
"ok": true,
"messageId": "18e…",
"conversationId": "18e…"
}
Optional warning string when present.
Errors
| Error code | When |
|---|---|
account_disconnected | Gmail missing/disconnected |
rate_limited | Inbox send RPM exceeded |
send_failed | Upstream Gmail failure |
not_found | Unknown campaign/lead |
MCP
Tool: send_message.