ZeroSettle vs Linq

ZeroSettle supports 33 of the 77 features compared here, and Linq supports 63.

Feature comparison

Feature	ZeroSettle	Linq
iMessage messaging
iMessage	Supported	Supported
Group chats	PartialUp to 31 people. Turned on per number by ZeroSettle support on request.	SupportedPro plan. Up to 31 recipients. No read or delivery receipts in groups.
Group management	SupportedCreate, rename, add, remove and leave. Needs group chats turned on for the number.	SupportedAdd and remove participants and leave a group, iMessage groups only, 3-member minimum.
Group name and photo	PartialGroup name can be set by API; group photo changes are only received as events.	SupportedSet display_name and group_chat_icon on group chats.
Mentions	Not listed	SupportedGroup chats only. Notifies iMessage recipients even in a muted chat.
Tapbacks	SupportedSix classic tapbacks: send, remove and receive through reaction webhooks.	SupportedSix classic tapbacks or any emoji, send and receive via reaction webhooks.
Threaded replies	Supportedreply_to on texts, photos, videos and polls, not on voice messages.	Supportedreply_to with optional part_index. iMessage only.
Typing indicators	SupportedSend, and receive as opt-in webhook events, in direct and group chats.	SupportedSend and receive, in direct and group chats. iMessage only.
Read receipts	Not supportedDocs: no read or delivered events; a send that returns 200 has only reached Apple.	SupportedMark chats read and receive message.read. One-to-one chats only.
Edit and unsend	Not supportedDocs: edit and unsend have no ZeroSettle equivalent.	PartialEdit text up to 5 times within 15 minutes. Delete does not unsend from the recipient's device.
Message effects	Supported13 bubble and screen effects, including invisible ink.	Supported11 screen and 4 bubble effects.
Animated text effects	Not listed	Supportedtext_decorations animations: big, small, shake, nod, explode, ripple, bloom, jitter.
Stickers	Not listed	SupportedPeel emoji or images onto messages, send stickers, or place them inline in text.
Formatted text	Not listed	SupportedBold, italic, underline and strikethrough ranges, plus animated text. iMessage only.
Attachments	PartialPhotos, videos (10 credits each) and voice messages only; documents cannot be sent.	SupportedUp to 10MB by URL, 100MB with pre-upload.
Live Photos	Not listedInbound Live Photos arrive as stills; sending is not documented.	Not listed
Rich link previews	Not listed	Supportedlink parts render as rich previews on iMessage and RCS.
Voice messages	SupportedNative audio bubble, sent and received.	SupportedDedicated voice memo endpoint renders the native iMessage voice bubble.
Contact cards	Not supportedDocs: contact cards cannot be sent.	SupportedSend .vcf files as media parts.
Polls	SupportedSend polls, read live results and receive poll.voted events. Only after the contact replies.	SupportedCreate, add options, vote and read tallies, with poll webhooks. Not as a chat's first message.
Chat backgrounds	SupportedSet or remove (preset or custom image) and receive background.changed events.	SupportedColor, animated or photo backgrounds, in direct and group chats.
Location sharing	Not supportedDocs: locations cannot be sent.	SupportedRequest, read and stop Find My shares. Live location is a $79/mo add-on on Pro.
iMessage apps	Not supportedDocs: Sendblue app cards have no ZeroSettle equivalent.	SupportedPro plan. Cards from your own Messages extension, or Linq-hosted cards (Experiences).
Live app cards	Not supportedNo iMessage app support.	SupportedUpdate App Card replaces a delivered iMessage app or Experience card in place.
Sender name and photo	SupportedBrand name and photo set by API and shared automatically with each new conversation.	SupportedContact card API sets name and photo, shared per chat via Name and Photo Sharing.
FaceTime calls	Not supportedDocs: the number exists only for iMessage.	Not supportedDocs say the API does not place or answer calls.
Delivery status	PartialSent and failed only; what happens after Apple accepts a message is not visible.	Supportedsent, delivered, read and failed webhooks. Groups report sent only.
iMessage availability check	Not supportedNo lookup endpoint; a first send to a non-iMessage handle returns 422 and sends nothing.	Supportedcheck_imessage and check_rcs endpoints.
Focus and Notify Anyway	Not listed	Not listed
Numbers and delivery
Managed lines	SupportedNumbers run on Apple hardware ZeroSettle operates in a server facility.	Supported
Dedicated numbers	SupportedEvery plan includes your own number; more can be added from the console or API.	SupportedPaid lines are dedicated. Provisioned by Linq, no self-serve number API.
Shared numbers	Not listed	SupportedFree Hobby tier uses a Shared Line, inbound-first, 20 contacts.
Bring your own number	Not supportedTerms: lines are provisioned, owned and controlled by ZeroSettle. No porting offered.	Not listed
Line pooling	SupportedSeveral numbers work as one: new contacts go to the line with most room left.	SupportedManaged load balancing (Pro): send without from and Linq picks and fails over lines.
SMS fallback	Not supportedDocs: iMessage only, with no SMS fallback.	Supported
RCS fallback	Not supportedDocs: iMessage only, with no RCS fallback.	SupportedOrder is iMessage, then RCS, then SMS.
Outbound-first messaging	Partial5 new contacts a day on Pro, 50 on Growth; at most 2 messages before a first reply.	SupportedFree Hobby tier is inbound-first. Docs recommend inbound-first flows to avoid flagging.
Calls on the iMessage number	Not supportedDocs: the number exists only for iMessage.	PartialAPI forwards inbound calls on the line; outbound needs caller-ID masking via another provider.
Other channels
SMS	Not supportedNo SMS channel; iMessage only.	Supported
RCS	Not supportedNo RCS channel; iMessage only.	Supported
WhatsApp	Not supportedNot offered	BetaSeparate WhatsApp API in beta. Access by request, no SLA.
Telegram	Not supported	Not supportedNot offered
Slack	Not supportedNot offered as a channel; docs show a Slack relay you build yourself.	Not supported
Email	Not supportedNot offered. iMessage can be sent to Apple ID email handles.	Not supportedNot offered. iMessage can be sent to Apple ID email handles.
Phone calls	Not supportedNot offered	PartialAPI does not place or answer calls; it forwards inbound calls. Calling lives in the Linq Blue app.
Apple Messages for Business	Not supported	Not listedAI context page mentions it, but no product page or docs were found.
Unified channel API	Not supportedSingle channel	PartialiMessage, RCS and SMS share one API. WhatsApp is a separate API with its own keys and SDKs.
Developer tools
REST API	SupportedBearer-token REST API.	Supported
TypeScript SDK	Not supportedDocs tell integrators to use plain HTTPS and JSON, no SDK.	Supported@linqapp/sdk
Python SDK	Not supported	Supportedlinq-python
Other SDKs	Not supported	SupportedOfficial Go SDK.
CLI	Not listed	Supported@linqapp/cli: signup, sending, and a local webhook listener.
Webhooks	SupportedOne URL gets message, reaction, poll, background, group and opt-in typing events.	Supported
Signed webhooks	SupportedHMAC-SHA256 over timestamp and raw body, 300 s tolerance.	SupportedHMAC-SHA256, Standard Webhooks format, with replay protection.
MCP server	SupportedRemote MCP server with OAuth 2.1, mainly for setup and testing; adds group and agent tools.	Supported@linqapp/sdk-mcp with docs search and code execution tools.
Open source	Not supportedProprietary hosted service; terms reserve all rights to the software.	PartialSDKs, CLI and adapters are Apache-2.0 or MIT on GitHub. The messaging platform is closed.
Self-hosting	Not supportedHosted only; lines run on hardware ZeroSettle owns and controls.	Not supportedLinq describes itself as fully managed, in contrast to self-hosted options.
Local testing	Partialtest_webhook sends a signed synthetic event; the operator can push simulated inbound events.	Not listedThe CLI streams webhooks locally, but tests still use a real phone.
Custom channel providers	Not listed	Not listed
Event replay	PartialWebhooks retried 3 times, no replay; catch up by paging messages with after_id.	PartialRetries for 30 minutes; after that, re-fetch chats or ask Linq for a manual replay.
OpenTelemetry	Not listed	PartialW3C trace IDs on every response and webhook for OTel backends. No export of Linq spans by default.
No-code integrations	SupportedZapier app with triggers and actions, and a GoHighLevel app.	SupportedLinq Blue works as a GoHighLevel messaging provider. No n8n, Make or Zapier found for the API.
CRM integrations	SupportedClose, HubSpot and GoHighLevel apps. Group messages are not logged in Close or HubSpot.	SupportedVia Linq Blue: GoHighLevel, HubSpot and Salesforce.
Built for AI agents
Agent framework	BetaHosted AI agent (Beta) with business context, triggers, files and MCP tools; no code framework.	PartialNo own framework. Maintains a Vercel Chat SDK adapter and OpenClaw and Hermes plugins.
Agent framework integrations	Not listed	SupportedLinq-maintained Vercel Chat SDK adapter, plus OpenClaw and Hermes Agent plugins.
Streaming replies	Not supportedNo message editing, so a reply cannot be streamed into one bubble.	Not supportedDocs say the Chat SDK adapter buffers streams into one final message.
Agent group chats	Not listedThe hosted agent never replies to other ZeroSettle numbers; API use is not documented.	Not listed
Human handoff	PartialTeam can answer in the console; the hosted agent is on or off per line group, no per-thread takeover.	Not listed
Audit logs	Not listed	SupportedDashboard Activity page plus account-change webhooks with actor and origin.
Message history API	SupportedCursor-paged history of every message in both directions.	Supported
Plans and compliance
Free plan	Not supportedNo free trial; a 30-day money-back guarantee instead.	SupportedHobby: $0, up to 20 contacts, through the CLI.
Public pricing	Supported	SupportedPro from $260/mo. Enterprise is custom.
No per-message fees	SupportedFlat per number. Videos and hosted-agent texts use included credits.	Supported
Uptime SLA	Not supportedHomepage cites 99.9% uptime, but ZeroSettle says it publishes no SLA.	SupportedContractual SLAs on the Enterprise plan; marketing cites 99.95%
Isolated infrastructure	PartialDocs refer to each number's own phone; the API and console are shared.	SupportedDedicated lines across 4 data centers on paid plans; Hobby uses a shared line
SOC 2 Type II	Not listedEnterprise plan lists 'SOC 2, DPA and security reviews'; no report or type is stated.	SupportedType I and Type II, reports for 2022, 2024, 2025 and 2026.
GDPR	PartialPrivacy policy covers EEA and UK rights and SCC transfers; a DPA is listed for Enterprise.	SupportedDPA covers GDPR and UK GDPR, with Standard Contractual Clauses.

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 ZeroSettle if you need local testing and human handoff.

Choose Linq if you need mentions, read receipts, edit and unsend and animated text effects.

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