Sendblue vs LoopMessage vs Blooio for an AI agent that receives replies
All three deliver replies to your agent by webhook; they differ on price, who may start a conversation, and how webhooks are secured and retried. Blooio has the strongest webhook tooling and the only hosted MCP server, LoopMessage has the lowest entry price and longest retry window, and Sendblue has the compliance paperwork. Claw Messenger, shown as a labelled fourth column, is the $5 option for an agent that talks to a known group and gets replies over a WebSocket.
Claw Messenger publishes this page. We sell one of the products compared.
The short answer
For a number of your own that receives replies, expect about $90 to $100 a month: Blooio Inbound $98, LoopMessage Light with number and fallback $89.99, Sendblue AI Agent $100. Pick on webhooks and outbound rules, not price.
- Best for
- Builders choosing a managed iMessage line for an agent where users text first and every reply must reach the backend.
- Not for
- High-volume cold outreach. All three cap or gate new conversations, and Claw Messenger self-serve is not built for it either.
At a glance
| Lowest entry | LoopMessage, $20/month shared sender |
|---|---|
| Signed webhooks (HMAC) | Blooio |
| Longest webhook retries | LoopMessage, 30 retries over about 3 hours |
| Replay of failed deliveries | Blooio |
| Hosted MCP server | Blooio |
| Reply-only plan | Blooio Inbound ($98); Sendblue AI Agent is inbound-first ($100) |
| Fallback included in price | Sendblue (RCS then SMS); LoopMessage shared senders; Claw Messenger |
| Published SOC 2 | Sendblue (Type II) |
| Fourth option | Claw Messenger, $5/month, replies over WebSocket |
Side-by-side comparison
Checked 6 November 2026 on each vendor's pricing and docs pages. Prices are monthly, in US dollars. The Claw Messenger column is shaded because we sell it.
| Question | Sendblue | LoopMessage | Blooio | Claw Messenger (ours, fourth option) |
|---|---|---|---|---|
| Cheapest production plan | $100/month per line (AI Agent plan) | $20/month shared sender (50 monthly contacts, AI assistants only). Own sender from $59.99/month | $39/month Starter (personal use, shared number) | $5/month Base: 250 messages, 1 registered number |
| Free testing | Sandbox: shared number, up to 10 verified contacts. No outbound, no webhooks | Sandbox: unlimited messages with 5 contacts, testing only | Free sandbox | No free tier. 7-day trial, card required |
| Reply-only or inbound-first plan | AI Agent plan is inbound-first. Unlimited replies within 24 hours of the contact's last message | An own sender replies only, unless you buy Init conversations | Inbound, $98/month: a number of your own that replies to anyone but cannot start conversations | No reply-only plan. Every plan is two-way with registered numbers |
| Starting conversations | Follow-ups after 24 hours capped at 200 contacts/line/day. Full outbound on Enterprise (custom price) | Init conversations add-on: +$30/month and $30 once, after warm-up, to recently opted-in contacts | 5 new/day on Starter, 15 on Commercial Shared ($89), no listed cap on the $289 own-number plan | Yes, to registered numbers. New recipients pause at 20 in a rolling 24 hours |
| Volume limits | 1,000 inbound contacts per line per day | Light: 300 unique active daily contacts. Regular ($99.99): 1,000 | No per-message billing cap on paid lines; safety controls apply | 250 to 15,000 messages a month, both directions; 1 to 50 registered numbers |
| How replies reach the agent | Webhook (receive event) | Webhook (message_inbound event), plus a webhook history API | Webhook (message.received event), plus an event feed | Outbound WebSocket the agent opens. No public URL needed |
| Webhook authentication | A secret you set, sent in a request header | An authorization header you set | HMAC-SHA256 signature over timestamp and body | No caller-supplied webhook on self-serve or Agency. The WebSocket is authenticated with your API key |
| Missed-delivery recovery | Up to 3 retries on a 5xx response; 45-second timeout | Up to 30 retries over about 3 hours; 15-second timeout | 6 attempts over about 15½ minutes; 15-second timeout; replay API for failed deliveries | Replies are saved first and return when the agent reconnects; a sync request replays from a timestamp |
| MCP server | Local, run with npx (sendblue-api-mcp) | Searches LoopMessage docs and helpdesk; no messaging tools listed | Hosted at mcp.blooio.com (OAuth or API key) | Local, run with npx (@emotion-machine/claw-messenger-mcp). No hosted server |
| Number per customer | One $100 line per number; multiple lines listed under Enterprise | Priced per sender, with volume discounts from 3 senders | Buy lines and assign each to its own API key and number pool | Agency: $199/month per sub-tenant, each with its own visible number, created by API. Invite-only, $250 onboarding |
| RCS and SMS fallback | RCS, then SMS, from the same number at no extra charge | Included on shared senders; +$15/month and $15 once on an own sender | iMessage sends can fall back to SMS; RCS is a separate registered channel | Automatic RCS and SMS fallback, included |
| Group chats | AI Agent numbers answer groups but cannot create them | Create-group API | Groups API (create, members, icon) | Growth plan and up (needs 2+ registered numbers) |
| Published compliance | SOC 2 Type II; HIPAA on Enterprise | Not published | SOC 2 Type 1 and Type 2 listed as in progress | No public SOC 2 or HIPAA claim |
Which one to pick
Pick Sendblue when compliance or calling decides it
Sendblue lists SOC 2 Type II and HIPAA on Enterprise, falls back to RCS and then SMS from the same number at no charge, and adds calling and FaceTime from that number. The $100 AI Agent plan is inbound-first, its sandbox has no webhooks, and its retry policy is the shortest of the three.
Pick LoopMessage when budget and retries decide it
LoopMessage has the lowest entry price and keeps retrying a webhook for about three hours, which rides out a long outage on your side. It also offers WhatsApp on the same number. Expect to add the phone number, fallback, and outbound options one at a time, and to authenticate webhooks with a header rather than a signature.
Pick Blooio when webhook tooling and MCP decide it
Blooio signs webhooks with HMAC-SHA256, gives each event a stable ID for deduplication, keeps a delivery log, and can replay a failed delivery once your endpoint is back. It is the only one of the three with a hosted MCP server. Its $98 Inbound plan fits an agent that users text first, but it cannot start conversations.
Consider Claw Messenger when the agent talks to people it knows
Claw Messenger costs $5 to $50 a month, lets the agent text registered numbers first, and includes RCS and SMS fallback. Replies arrive over a WebSocket the agent opens, so there is no public webhook to secure. A reply that lands while the agent is offline is saved and returned on reconnect. It is not a public line: inbound reaches you only from registered numbers, and the self-serve sending number is assigned automatically and shared across accounts. There is no free tier, no hosted MCP, and no public SOC 2 or HIPAA claim. Approved managed setups may use a separately configured webhook; see the docs.
If none of the three fits, the best iMessage API comparison adds Photon, Inkbox, ZeroSettle, Miss Blue and Apple Messages for Business, grouped by buyer.
What one line costs per month
One agent, people text it and it answers, with SMS or RCS fallback where offered. Checked 6 November 2026.
| Setup | Monthly | Can start conversations? |
|---|---|---|
| Sendblue AI Agent line | $100 | Inbound-first; follow-ups capped |
| LoopMessage Light sender + number + SMS/RCS fallback | $89.99, plus one-time fees | No |
| Same, plus Init conversations | $119.99, plus one-time fees | Yes, after warm-up and opt-in |
| Blooio Inbound | $98 | No (reply-only) |
| Blooio commercial plan with its own number | $289 | Yes |
| Claw Messenger Base / Growth / Pro (fourth option) | $5 / $15 / $50 | Yes, to registered numbers |
Build the reply path the same way for all three
Each provider times out a slow webhook and retries it, so the same event can arrive twice. Authenticate the request, store it and deduplicate on the event or message ID, answer 200 immediately, then hand the message to the agent from a queue. Do not run the model before you acknowledge the webhook. With a WebSocket route, the agent keeps one outbound connection open instead and reconnects with backoff.
FAQ
Which is cheapest: Sendblue, LoopMessage, or Blooio?
LoopMessage starts lowest at $20 per month for a shared sender with 50 monthly contacts, limited to AI assistant use. Blooio starts at $39 per month for personal use on a shared number. Sendblue starts at $100 per line per month. For a number of your own that receives replies, Blooio Inbound is $98, a LoopMessage Light sender with a phone number and SMS/RCS fallback is $89.99 plus one-time fees, and Sendblue is $100. Claw Messenger, a fourth option, starts at $5. Checked 6 November 2026.
Which one signs its webhooks?
Blooio signs each webhook with HMAC-SHA256 over the timestamp and raw body. Sendblue sends a secret you configure in a request header. LoopMessage sends an authorization header you configure. Claw Messenger delivers replies over an authenticated WebSocket instead of a caller-supplied webhook.
Which retries failed webhooks the longest?
LoopMessage retries up to 30 times over about three hours. Blooio makes 6 attempts over about 15 and a half minutes and lets you replay failed deliveries. Sendblue retries up to 3 times on a 5xx response. Claw Messenger saves replies and returns them when the agent reconnects.
Which has a hosted MCP server?
Blooio, at mcp.blooio.com. Sendblue and Claw Messenger ship MCP servers you run locally with npx. LoopMessage's MCP server searches its documentation.
Which one can my agent use to text people first?
Sendblue's $100 AI Agent plan is inbound-first; full outbound is on Enterprise. LoopMessage needs the Init conversations add-on, warm-up, and recent opt-in. Blooio allows 5 or 15 new conversations a day on shared plans and no listed daily cap on its $289 own-number plan; its $98 Inbound plan is reply-only. Claw Messenger lets the agent text registered numbers first on every plan.
Can each of my customers get their own number?
Sendblue lists multiple lines on Enterprise. LoopMessage prices per sender with volume discounts. Blooio lets you buy lines and assign each to its own API key. Claw Messenger Agency gives each sub-tenant its own visible number for $199 per month, created by API, after a $250 onboarding.
Sources
Checked 6 November 2026: Sendblue pricing, Sendblue limits, Sendblue webhooks, Sendblue MCP, LoopMessage pricing, LoopMessage webhooks, LoopMessage MCP, Blooio pricing, Blooio webhooks, Blooio MCP, Blooio Trust Center. Claw Messenger figures come from our pricing, plans and limits, and docs. If a figure is out of date, tell us.
Related: Sendblue alternatives, Claw Messenger vs Sendblue, Claw Messenger vs LoopMessage, Claw Messenger vs Blooio, and the full iMessage API comparison.
Claw Messenger publishes this page. We sell one of the products compared.
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