Identity and communications layer that gives AI agents email, phone/iMessage options, internet endpoints, Agent2Agent communication and credential-vault access.
Product sources: Inkbox official product/pricing surface + Y Combinator S26 company page
Inkbox gives an AI agent a persistent communications identity rather than forcing developers to stitch together separate email, telephony and tunneling services. Each identity can have an email inbox and public tunnel; optional phone numbers add voice and SMS/MMS, while iMessage and Agent2Agent provide additional communication paths.12 Contacts, notes and conversation context sit at the organization layer, and the credential vault can be scoped to specific agents.2
The developer surface includes API, SDK, CLI, skills and MCP access, plus integrations for agent harnesses including Hermes, OpenClaw, Claude Code, Codex, OpenCode and DeepSeek Harness.1 Agents can also self-sign up into a restricted provisional identity: before human verification they can send only to the supervising human and are subject to tight recipient limits; human approval unlocks plan-based capabilities.3
The current pricing page offers Free at $0 for 3 identities, Developer at $30/month for 10 identities, Startup at $200/month for 100 identities, and custom Enterprise pricing.4 Paid plans add dedicated phone-number allowances and larger mailbox quotas; U.S./Canada overages are listed at $0.03 per additional SMS/MMS or call minute, or $0.02 per message on a customer's own 10DLC campaign. An active managed 10DLC campaign is listed at $20/month.4
The free tier is substantial for evaluation because it includes email, a public URL, shared iMessage, Agent2Agent, contacts and vault access. Usage economics become more complex at production scale because phone numbers, messaging, calling, storage and campaign registration can add variable cost. There is also a current documentation inconsistency: the pricing page says Developer and Startup include 10 and 100 custom email domains respectively, while the custom-domain documentation says each custom domain costs $4/month.45 Buyers should confirm the applicable custom-domain charge before budgeting.
Inkbox handles sensitive communications and identity data. Its September 2, 2026 Privacy Policy says Customer Data may include emails, messages, attachments, call records and transcripts, contacts, notes, identity details and account configuration, and that authorized MCP clients may receive Customer Data within the permissions granted by the customer.6 The DPA governs customer-data processing and provides for data-protection obligations, subprocessors and customer assessment rights.7
Credential handling has a useful separation boundary: the vault documentation describes client-side, zero-knowledge encryption for API keys, login credentials, SSH keys and other secrets, with encryption and decryption occurring client-side.8 API keys are scope-bound, allowing agent-scoped keys to operate only as a specific identity while admin keys retain organization-level authority.9
Messaging compliance controls are unusually concrete for an agent communications product. Inkbox's phone documentation says recipients on the default SMS campaign must opt in by texting START, that STOP updates the recorded consent state, and that inbound calls/texts can be filtered with identity-level whitelist or blacklist rules.10 For higher-volume U.S. application-to-person messaging, Inkbox documents 10DLC brand/campaign registration, opt-in flows, STOP/HELP behavior and carrier review requirements.11 Shared iMessage requires the recipient to initiate the connection, while dedicated iMessage lines can initiate conversations; the pricing page states recipients can reply STOP to opt out.4
These are meaningful safeguards, but they do not remove the customer's responsibility for lawful outreach or independently prove operational security. The product is very young and the current fixed independent panel provides little exact-product validation. Y Combinator independently corroborates the active Summer 2026 company and the same agent-identity/communications product surface, but its profile is not a reliability or security benchmark.12
Inkbox is best suited to developers building agents that must communicate with real people or other agents over durable channels: support assistants, phone operators, sales or operations agents, agent fleets and systems that need email-based verification or inbound webhooks.2 Its SDK/CLI/MCP surfaces and integrations are especially useful when identities and communications need to be provisioned programmatically rather than manually.1
It is less suitable for teams that only need an internal chat agent, organizations unwilling to place communication records with a young external platform, or outbound-use cases that cannot implement consent, carrier and applicable-law requirements. High-volume messaging teams should validate their own 10DLC campaign setup and consent workflow before production use.11
unusually broad identity coverage across email, phone/SMS, iMessage, internet endpoints and Agent2Agent; free evaluation tier; SDK/CLI/MCP access; human-controlled provisional agent signup; scoped API keys; zero-knowledge credential vault; cross-channel contacts/context; and explicit SMS/iMessage consent and carrier-compliance controls.13810
sparse independent reliability/security evidence; a young service handling inherently sensitive communications and identity data; usage-based telecom costs on top of subscriptions; dedicated iMessage can initiate conversations and therefore still requires customer governance; and conflicting current first-party documentation on custom-domain pricing.45
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