What is the difference between AgentPhone and Project Blue?

AgentPhone supports 44 of the 77 features compared here, and Project Blue supports 42. AgentPhone adds threaded replies, chat backgrounds, RCS fallback, Python SDK and signed webhooks. Project Blue adds voice messages, FaceTime calls, shared numbers, bring your own number and line pooling.

How much do AgentPhone and Project Blue cost?

AgentPhone: Pay as you go with $5 of starting credit: $3 per number a month, $0.13 to $0.22 a voice minute and $0.02 per SMS segment, with iMessage lines at $150 or $250 a month and no per-message charge. Project Blue: Flat per-line pricing: $166 a month per line billed annually or $199 a month per line on a 12-month plan, with a free trial on a shared line.

Does Project Blue support threaded replies?

Project Blue does not list threaded replies on its site or in its docs.

Does Project Blue support chat backgrounds?

Project Blue does not list chat backgrounds on its site or in its docs.

Does Project Blue support RCS fallback?

Project Blue does not list RCS fallback on its site or in its docs.

AgentPhone vs Project Blue

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

AgentPhone

Phone numbers with voice, SMS and iMessage for AI agents

Starting price: $3/month per number plus usage; iMessage from $150/month per line
Free plan: $5 starting credit, no card required

Visit AgentPhone Read more

Project Blue

iMessage, SMS and FaceTime Audio lines inside your CRM

Starting price: $166/month per line, billed annually
Free plan: Free trial on a shared line, verified numbers only

Visit Project Blue Read more

AgentPhone supports 44 of the 77 features compared here, and Project Blue supports 42.

Where AgentPhone is ahead

and 4 more in the table below.

Where Project Blue is ahead

and 2 more in the table below.

Feature comparison

Feature	AgentPhone	Project Blue
iMessage messaging
iMessage	SupportediMessage lines are a separate number type (type=imessage).	Supported
Group chats	SupportediMessage groups arrive as one conversation with roster and sender; reply to the group id.	SupportedSend to groups of 2 to 32 by API. Not on trial accounts, and group sends do not sync to the CRM.
Group management	PartialStart a new group by listing recipients and rename it; adding or removing members is not documented.	PartialGroups are created by sending to a set of numbers. No add or remove member endpoints documented.
Group name and photo	PartialGroup name can be set by API; the group icon is only readable.	PartialgroupName can be set when a group is created. No group photo documented.
Mentions	Not listed	Not listed
Tapbacks	SupportedSix classic tapbacks, custom emoji on newer lines; inbound reactions via agent.reaction.	PartialSend or remove the six classic tapbacks on inbound iMessages. Receiving reactions is not documented.
Threaded replies	Supportedreply_to_message_id; also on WhatsApp.	Not listed
Typing indicators	SupportedSend only, best-effort, auto-expires after a few seconds.	PartialSend only, iMessage only, into an existing conversation. Inbound typing events not documented.
Read receipts	Not listedThe pricing page mentions read receipts; no API or webhook for them is documented.	Not listed
Edit and unsend	Not listed	Not listed
Message effects	Supported12 screen and bubble effects via send_style.	Supported4 bubble and 9 screen effects through the effect field. iMessage only.
Animated text effects	Not listed	Not listed
Stickers	Not listed	Not listed
Formatted text	Not listed	Not listed
Attachments	SupportedImages, video and files by URL; several images arrive as a carousel on iMessage.	SupportedImages, videos and vCards by URL.
Live Photos	Not listed	Not listed
Rich link previews	Not listed	Not listed
Voice messages	Not listed	SupportedAudio files sent as voice memos, plus AI text-to-speech voice memos.
Contact cards	SupportedvCard files can be sent as media (listed as a supported MMS type).	SupportedVCF files through mediaAttachmentUrl.
Polls	Not listed	Not listed
Chat backgrounds	SupportedSet or remove a background image per iMessage conversation.	Not listed
Location sharing	Not listedThe API has location endpoints returning coordinates per number, but their use is not described.	Not listed
iMessage apps	Not listed	Not listed
Live app cards	Not listed	Not listed
Sender name and photo	PartialContact card sets a display name and avatar on the iMessage number; $250/month line only.	SupportedSet, read and share a line's Share Name and Photo card by API.
FaceTime calls	Not listed	PartialFaceTime Audio only, outbound and inbound, on FaceTime-enabled accounts. Not on trials.
Delivery status	PartialMessages carry a status and failure reason; no delivery or read webhooks are documented.	PartialMessages carry a status field such as delivered. Webhooks cover only inbound and outbound messages.
iMessage availability check	SupportedLive check of iMessage, SMS and RCS reachability for a number before sending.	Supported
Focus and Notify Anyway	Not listed	Not listed
Numbers and delivery
Managed lines	SupportediMessage lines are ordered through the API and run by AgentPhone.	SupportedNo iPhone, Mac or SIM needed. Lines are set up remotely, usually within one business day.
Dedicated numbers	SupportedUS and Canada numbers at $3/month; dedicated iMessage lines at $250/month.	SupportedA dedicated line per rep, never shared. New lines are requested by API and provisioned by the team.
Shared numbers	Not listed	PartialTrial accounts only: a shared line that can reach verified numbers.
Bring your own number	Not listed	SupportedExisting numbers can be ported to Project Blue's carrier partner.
Line pooling	Not listed	SupportedSends without lineId are load balanced across your lines.
SMS fallback	SupportedFalls back to SMS/MMS when iMessage is not available.	SupportedFalls back to SMS from the same line when iMessage is unavailable.
RCS fallback	SupportediMessage-capable numbers deliver over RCS or SMS to non-Apple recipients.	Not listedHomepage describes fallback from iMessage to WhatsApp to SMS. RCS fallback is not described.
Outbound-first messaging	PartialOutbound iMessage lines: 50 new contacts a day per line; inbound-only lines do not start chats; SMS needs 10DLC.	SupportedLines are sold as outbound-ready. Guidelines rule out mass outbound iMessage.
Calls on the iMessage number	Not listed	SupportedDialer and FaceTime Audio calls from the same number as the messaging line.
Other channels
SMS	SupportedSMS and MMS; inbound works at once, outbound needs 10DLC.	Supported
RCS	BetaRCS Business Messaging is beta and concierge-onboarded: branded sender, quick-reply chips.	PartialRCS for rich media was rolled out in 2026. The API lists RCS as inbound only.
WhatsApp	BetaBeta, enabled per account. Connect your own WhatsApp Business Account; Meta bills you.	PartialHomepage lists WhatsApp as a fallback step. No WhatsApp option in the API, and llms.txt says it is not a WhatsApp API.
Telegram	Not supportedNot offered	Not supportedNot offered
Slack	Not supported	PartialSlack notifications for inbound replies. Not a messaging channel.
Email	Not supported	Not supportedDeveloper page says it is not a general email API.
Phone calls	SupportedInbound and outbound calls in webhook mode or hosted AI mode; also browser web calls.	SupportedCloud dialer with inbound, outbound, routing, recording and voicemail, plus a browser calling SDK.
Apple Messages for Business	Not supportedNot offered	Not supportedNot offered
Unified channel API	SupportedOne send endpoint for SMS, MMS, iMessage, RCS and WhatsApp; one agent.message webhook incl. voice.	PartialOne send endpoint covers iMessage and SMS. Calls and FaceTime use separate endpoints.
Developer tools
REST API	Supported	SupportedREST API with Bearer keys and an OpenAPI spec.
TypeScript SDK	Supportednpm install agentphone	Partial@tryprojectblue/dialer is a browser SDK for phone calls only. No messaging SDK.
Python SDK	Supportedpip install agentphone	Not listed
Other SDKs	Not listedDocs list only TypeScript and Python; an agentphone-go repo holds only a placeholder README.	Not listed
CLI	Not listedNo own CLI found; numbers can be provisioned through the Stripe Projects CLI.	Not listed
Webhooks	SupportedProject default webhook with per-agent overrides.	SupportedInbound and outbound message events and inbound FaceTime call events.
Signed webhooks	SupportedHMAC-SHA256 over timestamp and body, with a timestamp header for replay protection.	Not listedWebhook docs do not mention signatures.
MCP server	SupportedHosted MCP server (mcp.agentphone.ai) and npm package agentphone-mcp.	SupportedRemote MCP server with OAuth 2.1, plus an optional Claude Code plugin.
Open source	Not supportedClosed platform. The MCP server and framework integrations are MIT-licensed on GitHub.	PartialThe dialer SDK is MIT licensed on npm. The platform is closed.
Self-hosting	Not supportedHosted cloud service only	Not listedHosted service on Project Blue lines. Self-hosting is not mentioned.
Local testing	PartialBrowser web calls test a voice agent without a phone number; no message simulator found.	Not listedTrial accounts send real messages to verified numbers; docs say they are not a simulator.
Custom channel providers	Not listed	Not listed
Event replay	PartialFailed webhooks retry 5 times over about 20 hours; deliveries can be listed but not replayed.	Not supportedDocs say webhooks have no retries and failed deliveries are not replayed.
OpenTelemetry	Not listed	Not listed
No-code integrations	PartialAgentPhone block in Sim's no-code workflow builder; no Zapier, Make, n8n or GoHighLevel found.	SupportedGoHighLevel conversation provider with workflow actions and triggers. llms.txt also lists Zapier.
CRM integrations	Not listed	SupportedHubSpot and Close CRM. Salesforce is not listed.
Built for AI agents
Agent framework	SupportedHosted voice mode runs calls from a system prompt; conversation state rides along in webhooks.	Not listed
Agent framework integrations	SupportedVercel Chat SDK adapter, LangChain, CrewAI and OpenAI Agents SDK tools, Google ADK guide.	Not listed
Streaming replies	PartialVoice only: NDJSON streamed webhook replies start speech on the first chunk.	Not listed
Agent group chats	PartialAgents can create and take part in iMessage groups; agent-to-agent groups are not described.	Not listed
Human handoff	PartialVoice only: cold transfer of a call to a transferNumber, by the AI or your webhook.	PartialReps reply in the CRM inbox and can join group threads. No agent handoff controls documented.
Audit logs	Not listed	Not listed
Message history API	SupportedConversations with paginated messages and custom metadata; call transcripts.	SupportedList and get messages, inbound and outbound, with filters.
Plans and compliance
Free plan	Partial$5 starting credit, no card. Outbound calls need a top-up first.	PartialFree trial on a shared line to verified numbers. Some endpoints are off on trial.
Public pricing	Supported	Supported$166/month per line billed annually, or $199/month per line on a 12-month plan.
No per-message fees	PartialiMessage lines and WhatsApp have no per-message charge; SMS is $0.02 a segment, MMS $0.03.	SupportedFlat per-line pricing with unlimited texting under fair use.
Uptime SLA	Not supportedTerms promise no uptime; SLAs only if set in an order or separate agreement.	Not listedSite cites a 99.9% uptime record and a public status page. No contractual SLA found.
Isolated infrastructure	Not listedSub-accounts isolate agents, numbers and data per client; no dedicated infrastructure offer found.	PartialEach rep gets a dedicated line that is never shared. Other infrastructure is not described.
SOC 2 Type II	PartialSOC 2 Type I report as of July 30, 2026; Type II examination in progress.	Not listed
GDPR	SupportedPrivacy policy sets out GDPR legal bases for processing.	PartialPrivacy policy lists GDPR and UK GDPR rights. No DPA found.

Feature

AgentPhone

Project Blue

iMessage messaging

iMessage

iMessage lines are a separate number type (type=imessage).

Group chats

iMessage groups arrive as one conversation with roster and sender; reply to the group id.

Send to groups of 2 to 32 by API. Not on trial accounts, and group sends do not sync to the CRM.

Group management

PartialStart a new group by listing recipients and rename it; adding or removing members is not documented.

PartialGroups are created by sending to a set of numbers. No add or remove member endpoints documented.

Group name and photo

PartialGroup name can be set by API; the group icon is only readable.

PartialgroupName can be set when a group is created. No group photo documented.

Mentions

Not listed

Tapbacks

Six classic tapbacks, custom emoji on newer lines; inbound reactions via agent.reaction.

PartialSend or remove the six classic tapbacks on inbound iMessages. Receiving reactions is not documented.

Threaded replies

reply_to_message_id; also on WhatsApp.

Not listed

Typing indicators

Send only, best-effort, auto-expires after a few seconds.

PartialSend only, iMessage only, into an existing conversation. Inbound typing events not documented.

Read receipts

Not listedThe pricing page mentions read receipts; no API or webhook for them is documented.

Not listed

Edit and unsend

Not listed

Message effects

12 screen and bubble effects via send_style.

4 bubble and 9 screen effects through the effect field. iMessage only.

Animated text effects

Not listed

Stickers

Not listed

Formatted text

Not listed

Attachments

Images, video and files by URL; several images arrive as a carousel on iMessage.

Images, videos and vCards by URL.

Live Photos

Not listed

Rich link previews

Not listed

Voice messages

Not listed

Audio files sent as voice memos, plus AI text-to-speech voice memos.

Contact cards

vCard files can be sent as media (listed as a supported MMS type).

VCF files through mediaAttachmentUrl.

Polls

Not listed

Chat backgrounds

Set or remove a background image per iMessage conversation.

Not listed

Location sharing

Not listedThe API has location endpoints returning coordinates per number, but their use is not described.

Not listed

iMessage apps

Not listed

Live app cards

Not listed

Sender name and photo

PartialContact card sets a display name and avatar on the iMessage number; $250/month line only.

Set, read and share a line's Share Name and Photo card by API.

FaceTime calls

Not listed

PartialFaceTime Audio only, outbound and inbound, on FaceTime-enabled accounts. Not on trials.

Delivery status

PartialMessages carry a status and failure reason; no delivery or read webhooks are documented.

PartialMessages carry a status field such as delivered. Webhooks cover only inbound and outbound messages.

iMessage availability check

Live check of iMessage, SMS and RCS reachability for a number before sending.

Focus and Notify Anyway

Not listed

Numbers and delivery

Managed lines

iMessage lines are ordered through the API and run by AgentPhone.

No iPhone, Mac or SIM needed. Lines are set up remotely, usually within one business day.

Dedicated numbers

US and Canada numbers at $3/month; dedicated iMessage lines at $250/month.

A dedicated line per rep, never shared. New lines are requested by API and provisioned by the team.

Shared numbers

Not listed

PartialTrial accounts only: a shared line that can reach verified numbers.

Bring your own number

Not listed

Existing numbers can be ported to Project Blue's carrier partner.

Line pooling

Not listed

Sends without lineId are load balanced across your lines.

SMS fallback

Falls back to SMS/MMS when iMessage is not available.

Falls back to SMS from the same line when iMessage is unavailable.

RCS fallback

iMessage-capable numbers deliver over RCS or SMS to non-Apple recipients.

Not listedHomepage describes fallback from iMessage to WhatsApp to SMS. RCS fallback is not described.

Outbound-first messaging

PartialOutbound iMessage lines: 50 new contacts a day per line; inbound-only lines do not start chats; SMS needs 10DLC.

Lines are sold as outbound-ready. Guidelines rule out mass outbound iMessage.

Calls on the iMessage number

Not listed

Dialer and FaceTime Audio calls from the same number as the messaging line.

Other channels

SMS

SMS and MMS; inbound works at once, outbound needs 10DLC.

RCS

BetaRCS Business Messaging is beta and concierge-onboarded: branded sender, quick-reply chips.

PartialRCS for rich media was rolled out in 2026. The API lists RCS as inbound only.

BetaBeta, enabled per account. Connect your own WhatsApp Business Account; Meta bills you.

PartialHomepage lists WhatsApp as a fallback step. No WhatsApp option in the API, and llms.txt says it is not a WhatsApp API.

Not supportedNot offered

Slack

Not supported

PartialSlack notifications for inbound replies. Not a messaging channel.

Not supported

Not supportedDeveloper page says it is not a general email API.

Phone calls

Inbound and outbound calls in webhook mode or hosted AI mode; also browser web calls.

Cloud dialer with inbound, outbound, routing, recording and voicemail, plus a browser calling SDK.

Apple Messages for Business

Not supportedNot offered

Unified channel API

One send endpoint for SMS, MMS, iMessage, RCS and WhatsApp; one agent.message webhook incl. voice.

PartialOne send endpoint covers iMessage and SMS. Calls and FaceTime use separate endpoints.

Developer tools

REST API

REST API with Bearer keys and an OpenAPI spec.

TypeScript SDK

npm install agentphone

Partial@tryprojectblue/dialer is a browser SDK for phone calls only. No messaging SDK.

Python SDK

pip install agentphone

Not listed

Other SDKs

Not listedDocs list only TypeScript and Python; an agentphone-go repo holds only a placeholder README.

Not listed

CLI

Not listedNo own CLI found; numbers can be provisioned through the Stripe Projects CLI.

Not listed

Webhooks

Project default webhook with per-agent overrides.

Inbound and outbound message events and inbound FaceTime call events.

Signed webhooks

HMAC-SHA256 over timestamp and body, with a timestamp header for replay protection.

Not listedWebhook docs do not mention signatures.

MCP server

Hosted MCP server (mcp.agentphone.ai) and npm package agentphone-mcp.

Remote MCP server with OAuth 2.1, plus an optional Claude Code plugin.

Open source

Not supportedClosed platform. The MCP server and framework integrations are MIT-licensed on GitHub.

PartialThe dialer SDK is MIT licensed on npm. The platform is closed.

Self-hosting

Not supportedHosted cloud service only

Not listedHosted service on Project Blue lines. Self-hosting is not mentioned.

Local testing

PartialBrowser web calls test a voice agent without a phone number; no message simulator found.

Not listedTrial accounts send real messages to verified numbers; docs say they are not a simulator.

Custom channel providers

Not listed

Event replay

PartialFailed webhooks retry 5 times over about 20 hours; deliveries can be listed but not replayed.

Not supportedDocs say webhooks have no retries and failed deliveries are not replayed.

OpenTelemetry

Not listed

No-code integrations

PartialAgentPhone block in Sim's no-code workflow builder; no Zapier, Make, n8n or GoHighLevel found.

GoHighLevel conversation provider with workflow actions and triggers. llms.txt also lists Zapier.

CRM integrations

Not listed

HubSpot and Close CRM. Salesforce is not listed.

Built for AI agents

Agent framework

Hosted voice mode runs calls from a system prompt; conversation state rides along in webhooks.

Not listed

Agent framework integrations

Vercel Chat SDK adapter, LangChain, CrewAI and OpenAI Agents SDK tools, Google ADK guide.

Not listed

Streaming replies

PartialVoice only: NDJSON streamed webhook replies start speech on the first chunk.

Not listed

Agent group chats

PartialAgents can create and take part in iMessage groups; agent-to-agent groups are not described.

Not listed

Human handoff

PartialVoice only: cold transfer of a call to a transferNumber, by the AI or your webhook.

PartialReps reply in the CRM inbox and can join group threads. No agent handoff controls documented.

Audit logs

Not listed

Message history API

Conversations with paginated messages and custom metadata; call transcripts.

List and get messages, inbound and outbound, with filters.

Plans and compliance

Free plan

Partial$5 starting credit, no card. Outbound calls need a top-up first.

PartialFree trial on a shared line to verified numbers. Some endpoints are off on trial.

Public pricing

$166/month per line billed annually, or $199/month per line on a 12-month plan.

No per-message fees

PartialiMessage lines and WhatsApp have no per-message charge; SMS is $0.02 a segment, MMS $0.03.

Flat per-line pricing with unlimited texting under fair use.

Uptime SLA

Not supportedTerms promise no uptime; SLAs only if set in an order or separate agreement.

Not listedSite cites a 99.9% uptime record and a public status page. No contractual SLA found.

Isolated infrastructure

Not listedSub-accounts isolate agents, numbers and data per client; no dedicated infrastructure offer found.

PartialEach rep gets a dedicated line that is never shared. Other infrastructure is not described.

SOC 2 Type II

PartialSOC 2 Type I report as of July 30, 2026; Type II examination in progress.

Not listed

GDPR

PartialPrivacy policy lists GDPR and UK GDPR rights. No DPA found.

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

Pricing

AgentPhone

Pay as you go with $5 of starting credit: $3 per number a month, $0.13 to $0.22 a voice minute and $0.02 per SMS segment, with iMessage lines at $150 or $250 a month and no per-message charge.

Pricing model: usage-based, flat per line for iMessage

Source