What is the difference between Inkbox and rustpush?

Inkbox supports 45 of the 77 features compared here, and rustpush supports 39. Inkbox adds contact cards, managed lines, dedicated numbers, shared numbers and line pooling. rustpush adds group name and photo, mentions, edit and unsend, animated text effects and stickers.

How much do Inkbox and rustpush cost?

Inkbox: Free covers 3 identities with shared iMessage; Developer is $25 a month with a VoIP number; Startup is $167 a month with one dedicated iMessage number; Enterprise is custom. SMS/MMS and call minutes over allowance cost $0.03 each. rustpush: rustpush is free source under SSPL v1; you supply Apple hardware identifiers or an always-on iPhone relay, and anyone offering it as a service must publish their service's source.

Does rustpush support contact cards?

rustpush does not list contact cards on its site or in its docs.

Does rustpush support managed lines?

rustpush does not support managed lines.

Does rustpush support dedicated numbers?

rustpush does not support dedicated numbers.

Inkbox vs rustpush

Compare Inkbox and rustpush side by side: iMessage features, channels, developer tools, pricing and compliance, checked on each provider's own site.

Inkbox

Email, phone, iMessage and A2A identity for AI agents

Starting price: $25/month (Developer); $167/month for a dedicated iMessage number (Startup)
Free plan: Free: 3 identities, shared iMessage up to 2,000 messages a month and 3 recipients at a time

Visit Inkbox Read more

rustpush

Rust library for the iMessage, FaceTime and APNs protocols

Starting price: Free
Free plan: Free source (SSPL v1)

Visit rustpush Read more

Inkbox supports 45 of the 77 features compared here, and rustpush supports 39.

Where Inkbox is ahead

and 15 more in the table below.

Where rustpush is ahead

and 9 more in the table below.

Feature comparison

Feature	Inkbox	rustpush
iMessage messaging
iMessage	SupportedShared router service on every plan, or a dedicated line from the Startup plan.	SupportedRegisters as an Apple device and talks to Apple's servers directly; read from source, no docs
Group chats	SupportedDedicated lines only, 2 to 8 remote participants. Shared service is 1:1.	SupportedConversations carry a participant list and optional group name
Group management	PartialCreate a group by sending to 2 to 8 numbers. No add or remove member API in V1.	SupportedChangeParticipants messages add or remove members
Group name and photo	Not listed	SupportedRename and IconChange messages set a group's name and photo
Mentions	Not listed	SupportedMention message parts
Tapbacks	SupportedSend, replace and remove 7 tapbacks including eyes; inbound tapbacks arrive by webhook.	SupportedSix classic tapbacks plus emoji; sticker tapbacks are receive only
Threaded replies	Supportedreply_to_message_id in 1:1 and group chats, with thread reads. Falls back to a plain reply.	Supportedreply_guid and reply_part on messages
Typing indicators	PartialSend only, in 1:1 chats. Groups and inbound typing events are not supported.	SupportedTyping message type
Read receipts	PartialSend read receipts in 1:1 chats. No read status for your own sent messages is documented.	SupportedRead and Delivered message types
Edit and unsend	Not listed	SupportedEdit and Unsend message types
Message effects	Supported4 bubble and 9 full-screen send styles, in 1:1 and dedicated-line groups.	Supportedeffect field on messages
Animated text effects	Not listed	SupportedBig, small, shake, nod, explode, ripple, bloom and jitter
Stickers	Not listed	PartialSticker tapbacks are received; the code marks sending them as unsupported
Formatted text	Not listed	SupportedBold, italic, underline and strikethrough
Attachments	SupportedOne media item per message, uploads up to 10 MiB. No media before the recipient's first reply.	SupportedInline data or MMCS (iCloud) file transfer
Live Photos	Not listed	PartialReceived attachments carry a Live Photo flag; uploads always set it to false
Rich link previews	Not listed	SupportedLinkMeta with LPLinkMetadata rich link data
Voice messages	Not listed	Supportedvoice flag on messages
Contact cards	PartialThe router sends the agent's contact card on connect. Sending other vCards is not documented.	Not listed
Polls	Not listed	Not listed
Chat backgrounds	Not listed	SupportedSetTranscriptBackground sets or removes a chat background
Location sharing	Not listed	PartialFind My clients read friends' and items' locations; OpenBubbles says sharing live location is unsupported
iMessage apps	Not listed	SupportedExtension app balloons with template layouts
Live app cards	Not listed	SupportedUpdateExtension messages update a sent app balloon
Sender name and photo	SupportedDedicated lines share the identity's display name and avatar automatically.	SupportedShare Name and Photo, including contact posters
FaceTime calls	Not listedCalls run over iMessage lines, but the docs do not say whether they are FaceTime.	SupportedCreate, ring, join and leave FaceTime sessions
Delivery status	Supportedimessage.sent, imessage.delivered and imessage.delivery_failed webhooks, per recipient in groups.	SupportedDelivered and Read receipts plus error messages
iMessage availability check	SupportedReturns iMessage, SMS or RCS for any E.164 number.	SupportedIDS lookups validate targets before sending
Focus and Notify Anyway	Not listed	SupportedNotifyAnyways messages; StatusKit shares and receives Focus status
Numbers and delivery
Managed lines	SupportedShared router lines and dedicated lines run by Inkbox. No Mac needed.	Not supportedA library; you register your own Apple ID and device identity
Dedicated numbers	SupportedStartup plan includes one dedicated iMessage number. VoIP numbers for calls and SMS from Developer.	Not supportedNot offered
Shared numbers	SupportedFree and paid plans include shared iMessage. The human must text the router first.	Not supported
Bring your own number	Not listed	SupportedYour own Apple ID; a phone number registers through an iPhone running a relay app
Line pooling	BetaOrganization-owned shared iMessage pools, beta and by request only.	Not listed
SMS fallback	SupportedInkbox tries iMessage first and can fall back to SMS; was_downgraded marks it.	Not listed
RCS fallback	PartialDocs describe SMS fallback, and the service field can report rcs. The transport cannot be chosen.	Not listed
Outbound-first messaging	PartialDedicated lines can start chats, up to 40 new recipients a day. Shared service needs the human to text first.	SupportedSend to any handle after an IDS key lookup
Calls on the iMessage number	SupportedAgents place and receive voice calls over shared and dedicated iMessage lines.	PartialFaceTime on the same Apple ID; no phone calls
Other channels
SMS	SupportedSMS and MMS on dedicated VoIP numbers, US and Canada included. Group MMS is beta.	PartialSMS message type, sent through text forwarding from a registered iPhone
RCS	PartialOnly as a transport reported on iMessage lines; not a channel you can pick.	Not listed
WhatsApp	Not supportedNot offered	Not supportedNot offered
Telegram	Not supported	Not supported
Slack	BetaSlack is in beta: read, reply, files and retained history search.	Not supported
Email	SupportedEach identity gets a mailbox, with custom domains and IMAP/SMTP access.	Not supported
Phone calls	SupportedInbound and outbound calls with your own WebSocket agent or Inkbox Voice AI (beta).	Not supportedNot offered; FaceTime only
Apple Messages for Business	Not supportedNot offered	Not supportedNot offered
Unified channel API	PartialOne identity and one webhook subscription across channels, but separate APIs per channel.	PartialiMessage and forwarded SMS share one message type; no other channels
Developer tools
REST API	Supported	Not supportedRust library only; no HTTP API
TypeScript SDK	Supported@inkbox/sdk	Not listedRust crate only
Python SDK	Supportedinkbox on PyPI	Not listed
Other SDKs	SupportedRust SDK (inkbox crate).	PartialThe library itself is a Rust crate; no other language bindings found
CLI	Supported@inkbox/cli	Not listed
Webhooks	Supported	Not supportedLibrary only; your code receives messages directly, no webhooks
Signed webhooks	SupportedHMAC-SHA256 with a per-identity signing key.	Not supportedNo webhooks
MCP server	SupportedRemote Streamable HTTP endpoint at inkbox.ai/mcp, with a separate ChatGPT endpoint.	Not listed
Open source	PartialSDK, CLI, skills and examples are MIT on GitHub. The service is closed.	PartialSource under SSPL v1; the Mac validation-data module is a closed-source stub
Self-hosting	Not listed	SupportedRuns inside your own application
Local testing	Not listed	Not listed
Custom channel providers	Not listed	Not listed
Event replay	SupportedDelivery log with replay. Incoming-call and Slack deliveries cannot be replayed.	Not listed
OpenTelemetry	Not listed	Not listed
No-code integrations	Not listed	Not listed
CRM integrations	Not listed	Not listed
Built for AI agents
Agent framework	PartialIdentity layer with contact memories across email, texts and calls. No conversation framework.	Not listed
Agent framework integrations	SupportedPlugins for Hermes Agent, OpenClaw, OpenCode, Codex, Claude Code and DeepSeek Harness.	Not listed
Streaming replies	Not listed	Not listed
Agent group chats	Not listedAgents can reach each other over A2A tasks, but not in group chats.	Not listed
Human handoff	PartialPeople can reply from the Console, and Voice AI can transfer a call. No handoff controls for agents.	Not listed
Audit logs	Not listed	Not listed
Message history API	SupportedList and read conversations and threads, with search on texts and email.	SupportedMessages in iCloud sync for chats, messages and attachments
Plans and compliance
Free plan	SupportedFree: 3 identities, shared iMessage up to 2,000 messages a month and 3 recipients at a time.	SupportedFree source under SSPL v1
Public pricing	Supported	Not listedNo prices or commercial license terms published
No per-message fees	PartialiMessage is capped per plan with no per-message fee. Extra SMS/MMS and call minutes cost $0.03 each.	SupportedNo fees; free source
Uptime SLA	Not listed	Not supportedSSPL disclaims all warranty
Isolated infrastructure	PartialDedicated iMessage infrastructure is listed for Enterprise only.	SupportedRuns in your own process and infrastructure
SOC 2 Type II	Not listed	Not listedSelf-hosted; compliance is up to the operator
GDPR	Not listedThe DPA names the CCPA only; GDPR is not mentioned.	Not listed

Feature

Inkbox

rustpush

iMessage messaging

iMessage

Shared router service on every plan, or a dedicated line from the Startup plan.

Registers as an Apple device and talks to Apple's servers directly; read from source, no docs

Group chats

Dedicated lines only, 2 to 8 remote participants. Shared service is 1:1.

Conversations carry a participant list and optional group name

Group management

PartialCreate a group by sending to 2 to 8 numbers. No add or remove member API in V1.

ChangeParticipants messages add or remove members

Group name and photo

Not listed

Rename and IconChange messages set a group's name and photo

Mentions

Not listed

Mention message parts

Tapbacks

Send, replace and remove 7 tapbacks including eyes; inbound tapbacks arrive by webhook.

Six classic tapbacks plus emoji; sticker tapbacks are receive only

Threaded replies

reply_to_message_id in 1:1 and group chats, with thread reads. Falls back to a plain reply.

reply_guid and reply_part on messages

Typing indicators

PartialSend only, in 1:1 chats. Groups and inbound typing events are not supported.

Typing message type

Read receipts

PartialSend read receipts in 1:1 chats. No read status for your own sent messages is documented.

Read and Delivered message types

Edit and unsend

Not listed

Edit and Unsend message types

Message effects

4 bubble and 9 full-screen send styles, in 1:1 and dedicated-line groups.

effect field on messages

Animated text effects

Not listed

Big, small, shake, nod, explode, ripple, bloom and jitter

Stickers

Not listed

PartialSticker tapbacks are received; the code marks sending them as unsupported

Formatted text

Not listed

Bold, italic, underline and strikethrough

Attachments

One media item per message, uploads up to 10 MiB. No media before the recipient's first reply.

Inline data or MMCS (iCloud) file transfer

Live Photos

Not listed

PartialReceived attachments carry a Live Photo flag; uploads always set it to false

Rich link previews

Not listed

LinkMeta with LPLinkMetadata rich link data

Voice messages

Not listed

voice flag on messages

Contact cards

PartialThe router sends the agent's contact card on connect. Sending other vCards is not documented.

Not listed

Polls

Not listed

Chat backgrounds

Not listed

SetTranscriptBackground sets or removes a chat background

Location sharing

Not listed

PartialFind My clients read friends' and items' locations; OpenBubbles says sharing live location is unsupported

iMessage apps

Not listed

Extension app balloons with template layouts

Live app cards

Not listed

UpdateExtension messages update a sent app balloon

Sender name and photo

Dedicated lines share the identity's display name and avatar automatically.

Share Name and Photo, including contact posters

FaceTime calls

Not listedCalls run over iMessage lines, but the docs do not say whether they are FaceTime.

Create, ring, join and leave FaceTime sessions

Delivery status

imessage.sent, imessage.delivered and imessage.delivery_failed webhooks, per recipient in groups.

Delivered and Read receipts plus error messages

iMessage availability check

Returns iMessage, SMS or RCS for any E.164 number.

IDS lookups validate targets before sending

Focus and Notify Anyway

Not listed

NotifyAnyways messages; StatusKit shares and receives Focus status

Numbers and delivery

Managed lines

Shared router lines and dedicated lines run by Inkbox. No Mac needed.

Not supportedA library; you register your own Apple ID and device identity

Dedicated numbers

Startup plan includes one dedicated iMessage number. VoIP numbers for calls and SMS from Developer.

Not supportedNot offered

Shared numbers

Free and paid plans include shared iMessage. The human must text the router first.

Not supported

Bring your own number

Not listed

Your own Apple ID; a phone number registers through an iPhone running a relay app

Line pooling

BetaOrganization-owned shared iMessage pools, beta and by request only.

Not listed

SMS fallback

Inkbox tries iMessage first and can fall back to SMS; was_downgraded marks it.

Not listed

RCS fallback

PartialDocs describe SMS fallback, and the service field can report rcs. The transport cannot be chosen.

Not listed

Outbound-first messaging

PartialDedicated lines can start chats, up to 40 new recipients a day. Shared service needs the human to text first.

Send to any handle after an IDS key lookup

Calls on the iMessage number

Agents place and receive voice calls over shared and dedicated iMessage lines.

PartialFaceTime on the same Apple ID; no phone calls

Other channels

SMS

SMS and MMS on dedicated VoIP numbers, US and Canada included. Group MMS is beta.

PartialSMS message type, sent through text forwarding from a registered iPhone

RCS

PartialOnly as a transport reported on iMessage lines; not a channel you can pick.

Not listed

Not supportedNot offered

Not supported

Slack

BetaSlack is in beta: read, reply, files and retained history search.

Not supported

Each identity gets a mailbox, with custom domains and IMAP/SMTP access.

Not supported

Phone calls

Inbound and outbound calls with your own WebSocket agent or Inkbox Voice AI (beta).

Not supportedNot offered; FaceTime only

Apple Messages for Business

Not supportedNot offered

Unified channel API

PartialOne identity and one webhook subscription across channels, but separate APIs per channel.

PartialiMessage and forwarded SMS share one message type; no other channels

Developer tools

REST API

Not supportedRust library only; no HTTP API

TypeScript SDK

@inkbox/sdk

Not listedRust crate only

Python SDK

inkbox on PyPI

Not listed

Other SDKs

Rust SDK (inkbox crate).

PartialThe library itself is a Rust crate; no other language bindings found

CLI

@inkbox/cli

Not listed

Webhooks

Not supportedLibrary only; your code receives messages directly, no webhooks

Signed webhooks

HMAC-SHA256 with a per-identity signing key.

Not supportedNo webhooks

MCP server

Remote Streamable HTTP endpoint at inkbox.ai/mcp, with a separate ChatGPT endpoint.

Not listed

Open source

PartialSDK, CLI, skills and examples are MIT on GitHub. The service is closed.

PartialSource under SSPL v1; the Mac validation-data module is a closed-source stub

Self-hosting

Not listed

Runs inside your own application

Local testing

Not listed

Custom channel providers

Not listed

Event replay

Delivery log with replay. Incoming-call and Slack deliveries cannot be replayed.

Not listed

OpenTelemetry

Not listed

No-code integrations

Not listed

CRM integrations

Not listed

Built for AI agents

Agent framework

PartialIdentity layer with contact memories across email, texts and calls. No conversation framework.

Not listed

Agent framework integrations

Plugins for Hermes Agent, OpenClaw, OpenCode, Codex, Claude Code and DeepSeek Harness.

Not listed

Streaming replies

Not listed

Agent group chats

Not listedAgents can reach each other over A2A tasks, but not in group chats.

Not listed

Human handoff

PartialPeople can reply from the Console, and Voice AI can transfer a call. No handoff controls for agents.

Not listed

Audit logs

Not listed

Message history API

List and read conversations and threads, with search on texts and email.

Messages in iCloud sync for chats, messages and attachments

Plans and compliance

Free plan

Free: 3 identities, shared iMessage up to 2,000 messages a month and 3 recipients at a time.

Free source under SSPL v1

Public pricing

Not listedNo prices or commercial license terms published

No per-message fees

PartialiMessage is capped per plan with no per-message fee. Extra SMS/MMS and call minutes cost $0.03 each.

No fees; free source

Uptime SLA

Not listed

Not supportedSSPL disclaims all warranty

Isolated infrastructure

PartialDedicated iMessage infrastructure is listed for Enterprise only.

Runs in your own process and infrastructure

SOC 2 Type II

Not listed

Not listedSelf-hosted; compliance is up to the operator

GDPR

Not listedThe DPA names the CCPA only; GDPR is not mentioned.

Not listed

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

Pricing

Inkbox

Free covers 3 identities with shared iMessage; Developer is $25 a month with a VoIP number; Startup is $167 a month with one dedicated iMessage number; Enterprise is custom. SMS/MMS and call minutes over allowance cost $0.03 each.

Pricing model: monthly plans with allowances, plus per-unit SMS/MMS and call-minute overage

Source

rustpush

rustpush is free source under SSPL v1; you supply Apple hardware identifiers or an always-on iPhone relay, and anyone offering it as a service must publish their service's source.

Pricing model: free self-hosted library

Source