Comms by Osis vs Sendblue

Comms by Osis supports 43 of the 77 features compared here, and Sendblue supports 58.

Feature comparison

Feature	Comms by Osis	Sendblue
iMessage messaging
iMessage	Supported	Supported
Group chats	SupportedGroups of 2 to 31 people from a dedicated line with group support. Not on the shared line.	BetaGroup API is in beta on select plans. AI Agent plan can only reply in existing groups.
Group management	PartialCreate a group with its first message; adding or removing members is not documented.	BetaAdd and remove participants in iMessage groups via the beta groups API.
Group name and photo	PartialName a group when you create it; group photos and renames are not documented.	SupportedRename groups and set group photos on supported lines.
Mentions	Not listed	Not listed
Tapbacks	SupportedClassic tapbacks or custom emoji, add, replace or remove; reaction webhooks for inbound.	PartialSend classic tapbacks or any emoji. No inbound reaction events documented.
Threaded replies	Supportedreply_to_message_id replies inside an iMessage thread; text only.	Supportedreply_to on V2 iMessage lines, in direct and group chats.
Typing indicators	SupportedShow or hide typing dots on iMessage, RCS and WhatsApp.	SupportedSend and receive. iMessage 1:1 only, not in groups.
Read receipts	SupportedMark a conversation read to send a receipt; comms.message.read for one-to-one chats.	PartialCan mark chats read (1:1). Outbound statuses stop at DELIVERED, with no read status.
Edit and unsend	PartialUnsend within Apple's 2-minute window on supported lines. No edit endpoint; inbound edits fire events.	Not supportedDocs say editing is not supported via API and delete does not unsend.
Message effects	Not listed	Supported13 send_style values.
Animated text effects	Not listed	Not listed
Stickers	Not listed	Not listed
Formatted text	Not listed	Not listed
Attachments	SupportedUp to 32 files and 9 MiB per message, sent as base64.	SupportedUp to 100MB on iMessage, 5MB on SMS.
Live Photos	Not listed	Not listed
Rich link previews	Not listed	PartialDocs say links expand only after the recipient saves your contact.
Voice messages	Not listedVoice notes are documented for WhatsApp only.	SupportedSend .caf files to render as inline voice notes.
Contact cards	SupportedSend a vCard over iMessage, SMS or WhatsApp.	SupportedSend .vcf files via media_url.
Polls	Supported2 to 12 options; votes arrive as comms.poll.voted. Tap to vote on iOS 26 and later.	Not listed
Chat backgrounds	BetaExperimental: photo or gradient backgrounds on lines that support them.	Not listed
Location sharing	PartialRead locations that contacts choose to share, with update webhooks; the API cannot request a share.	SupportedFind My request, read and live watch. Dedicated iMessage lines only.
iMessage apps	Not listed	SupportedApp Cards for your own Messages extension. V2 lines, not on the free plan.
Live app cards	Not listed	PartialUpdates go out as new messages in the same App Card session; Sendblue says the original is not edited.
Sender name and photo	SupportedContact card API sets name and photo, with native name and photo sharing on supported lines.	SupportedName and Photo Sharing profile per line, shared into direct iMessage chats.
FaceTime calls	PartialAnswer inbound FaceTime audio and video calls by API and stream audio; outbound calls not documented.	PartialOutbound FaceTime audio over WebRTC (Agora). Needs a purchased FaceTime line.
Delivery status	Supportedsent, delivered and read events, plus a list of delivery attempts.	SupportedStatus callbacks from REGISTERED through SENT or DELIVERED.
iMessage availability check	SupportedChecks iMessage, RCS and WhatsApp for a phone number, or iMessage for an email.	SupportedLookup API checks a phone number or email for iMessage.
Focus and Notify Anyway	Not listed	Not listed
Numbers and delivery
Managed lines	SupportedHosted lines; no Mac to run.	Supported
Dedicated numbers	SupportedDedicated plan: $200 a month per number.	Supported
Shared numbers	SupportedFree and Plus plans run on a shared platform line.	SupportedFree sandbox uses a shared number with verified contacts only.
Bring your own number	SupportedPort an existing number to a dedicated line; needs approval and a supported number.	PartialOnly by porting the number in, which adds 3 to 5 days.
Line pooling	Not listed	SupportedNumber pooling with sticky sending. Automatic line selection needs account enablement.
SMS fallback	SupportedAuto routing falls back to SMS only after a clear rejection.	Supported
RCS fallback	PartialAuto routing tries RCS for plain text on supported dedicated lines with carrier enablement.	SupportediMessage, then RCS, then SMS. RCS on V2 lines.
Outbound-first messaging	SupportedDedicated lines can start conversations.	SupportedFull outbound on Enterprise or Blue Ocean; Free and AI Agent plans are inbound-first
Calls on the iMessage number	PartialInbound phone and FaceTime calls to the line can be answered by API; outbound is not documented.	SupportedDashboard calls and FaceTime from the texting number; API calls via your Twilio caller ID.
Other channels
SMS	SupportedChoose sms explicitly or let auto routing fall back to it.	Supported
RCS	PartialOne plain-text message to one number, on supported dedicated lines with carrier enablement.	SupportedV2 lines.
WhatsApp	SupportedSends from the number's WhatsApp Business account when WhatsApp is turned on for it.	Not supportedNot offered
Telegram	Not supportedNot offered	Not supported
Slack	Not supported	Not listed
Email	Not supportedNot offered as a channel; the capability check accepts Apple ID emails for iMessage.	Not supportedNot offered. iMessage can be sent to Apple ID email addresses.
Phone calls	PartialInbound cellular calls can be answered by API, but audio relay works only for FaceTime for now.	PartialNo native calling API. Dashboard calls, outbound via your Twilio caller ID, inbound forwarding.
Apple Messages for Business	Not supportedNot offered; the site says Comms is distinct from Apple Messages for Business.	Not supportedNot offered
Unified channel API	SupportedOne send endpoint and message model for iMessage, RCS, WhatsApp and SMS.	SupportedOne API for iMessage, RCS and SMS, the only channels offered.
Developer tools
REST API	Supported	Supported
TypeScript SDK	Not listedOnly a runnable Node.js example is published.	Supportedsendblue on npm.
Python SDK	Not listed	Supportedsendblue on PyPI.
Other SDKs	Not listed	PartialGo, Rust and Ruby packages, listed as community packages.
CLI	Not listed	Supported@sendblue/cli: signup, messaging, contacts and webhooks.
Webhooks	Supported	Supported
Signed webhooks	SupportedHMAC-SHA256 in X-Osis-Signature.	PartialSends your shared secret in an sb-signing-secret header. No HMAC signature.
MCP server	SupportedHosted MCP server with OAuth or a scoped API key.	Supportedsendblue-api-mcp via npx.
Open source	Not listed	PartialSDKs and CLI are MIT or Apache-2.0 on GitHub. The messaging platform is closed.
Self-hosting	Not listed	Not listedSold as a hosted service on Sendblue's Apple devices; self-hosting is not mentioned.
Local testing	Not listed	Not listed
Custom channel providers	Not listed	Not listed
Event replay	PartialUp to six delivery retries and a delivery attempts list; no replay endpoint is documented.	PartialNo replay. Docs say to repair gaps by listing messages updated since a timestamp.
OpenTelemetry	Not listed	Not listed
No-code integrations	BetaHighLevel connector is a development preview; Marketplace approval is pending.	SupportedZapier, Make and GoHighLevel. Docs FAQ says n8n resources are coming soon.
CRM integrations	Not listed	SupportedGoHighLevel, HubSpot, Salesforce, Close and Monday.com.
Built for AI agents
Agent framework	SupportedHosted agents with instructions, knowledge, handoff and MCP tool connections.	PartialNo own framework. Maintains a Vercel Chat SDK adapter.
Agent framework integrations	Not listed	SupportedSendblue-maintained Vercel Chat SDK adapter.
Streaming replies	Not listed	Not supportedDocs say message editing is not supported via the API.
Agent group chats	Not listed	BetaA line can add another of your own dedicated lines to a group, via the beta groups API.
Human handoff	SupportedHandoff controls pause the hosted agent while a person replies in the team inbox.	SupportedShared team inboxes with assignment, and agents that escalate to a rep.
Audit logs	Not listed	PartialSecurity page says all API requests are logged. No customer-facing audit log documented.
Message history API	SupportedList messages and conversations on your lines.	Supported
Plans and compliance
Free plan	SupportedFree: shared platform line, 100 messages a day, no card.	SupportedFree sandbox: shared number, up to 10 verified contacts, no webhooks.
Public pricing	Supported	SupportedAI Agent plan at $100/mo per line. Enterprise is custom.
No per-message fees	SupportedFlat plans; AI usage and answered call minutes are billed separately.	Supported
Uptime SLA	Not listed	Supported99.99% uptime SLA on the Enterprise plan
Isolated infrastructure	Not listed	SupportedA dedicated HIPAA instance for HIPAA customers
SOC 2 Type II	Not listed	SupportedSOC 2 Type II, report on request.
GDPR	Not listedThe privacy policy mentions GDPR rights; no DPA was found.	SupportedPrivacy policy says Sendblue adheres to GDPR. DPAs on request.

Checked on each provider's own site and docs on 2026-10-25. “Not listed” means the provider does not mention it.

Pricing

Which should you choose?

Choose Comms by Osis if you need edit and unsend, polls, chat backgrounds and WhatsApp.

Choose Sendblue if you need message effects, rich link previews, voice messages and iMessage apps.

Frequently asked questions

• Photon vs Comms by Osis
• Comms by Osis vs Linq
• Blooio vs Comms by Osis
• Comms by Osis vs Zernio
• Comms by Osis vs LoopMessage
• Blue Reacher vs Comms by Osis
• Chert vs Comms by Osis
• Comms by Osis vs Miss Blue
• Bland vs Comms by Osis

• Photon vs Sendblue
• Sendblue vs Linq
• Blooio vs Sendblue
• Sendblue vs Zernio
• LoopMessage vs Sendblue
• Blue Reacher vs Sendblue
• Chert vs Sendblue
• Miss Blue vs Sendblue
• Bland vs Sendblue
• BlueBubbles vs Sendblue