Zavu Inbox

Zavu Inbox is a messaging API with a web inbox for teams building communication into their products and workflows. It is best suited to developers who want channels and AI agents under one API; the prepaid sending rule and narrow free-tier quota call for careful budgeting.

Overview

Zavu organizes messages into threads across their channels, with the most recently active threads first. Its API handles sending and receiving, and can choose a channel based on the recipient and the sender’s configured channels. That centralized routing is useful when an application needs to reach people through different channels; it is less compelling for teams that only need a conventional shared email inbox.

Agents can respond across messaging channels and phone, draw on agent-specific knowledge bases and memory, and call customer-owned tools. This makes Zavu a foundation for custom agent workflows, not a complete, ready-made support operation. The maker describes the product as open source, but its hosted plans still have usage terms and paid services to weigh.

Key features

Channels, inbox and routing

Supported channels include WhatsApp, SMS, one-way SMS, voice, email, Telegram, Instagram and Messenger. Threads bring a contact’s channel messages together and sort by recent activity, making the inbox a useful view across conversations. Automatic channel selection can simplify sending, though teams still need to account for which channels they have connected.

Agents and developer access

Agents can use channel and phone conversations, their own knowledge bases and memory, and tools owned by the customer. TypeScript, Python, Ruby, Go and PHP SDKs are joined by an MCP server, agent skills, a CLI, an n8n node and a Vercel Marketplace integration. This is a practical range for teams building around the API. Zapier, Make, HubSpot, Salesforce, Shopify, WooCommerce, Zendesk, Intercom and GitHub are marked as coming soon, so they should not be treated as current integrations.

Webhook security and sending continuity

Webhooks use an X-Zavu-Signature with HMAC; v2, which signs the timestamp together with the body, is the default for new senders. A prepaid balance reaching zero stops sending, while inbound messages and webhooks continue to work. That separation helps preserve incoming events, but an application that depends on outbound replies needs to monitor its balance and restore credit promptly.

Pricing

The free plan costs nothing, is free forever, and includes two channel connections, 2,000 monthly messages shared across WhatsApp, Telegram, Instagram and Messenger, and $2 of monthly usage credit. It is a useful starting point, but the shared cap and two-connection ceiling make it a limited production allowance. Free users get an in-product assistant and Discord community support.

Pro costs $20 a month, billed monthly. It includes $20 monthly usage credit, unlimited channel connections, 2M memory units per month and prepaid usage. It is the natural step for teams that outgrow the free connection or message allowance, but the prepaid condition remains important: sending stops at a zero balance. Pro adds direct chat with Zavu engineers from 9am to 7pm Eastern Time, Monday to Friday.

Managed costs $1,250 a month at 50% off launch pricing; the normal price is $2,500 per month. It adds weekly conversation review, ongoing tuning and 24/7 support with a 30-minute response SLA. This is aimed at teams that want continuing operational help, rather than only API access.

Build costs $2,450, paid once at 50% off launch pricing; the normal price is $4,900. It covers an agent designed, built and shipped in the customer’s Zavu account over four to six weeks. Choose it for a defined implementation engagement, not ongoing managed support.

Enterprise has custom pricing, postpaid invoicing with NET-30, negotiated rates, multi-zone redundancy and an uptime SLA, plus a named engineer. It is the option for organizations that need negotiated commercial terms and specified operational assurances.

Voice agents start at $0.07 per minute; premium models and voices cost extra, and BYOK is unavailable for voice agents. Teams using voice should budget for those charges separately from plan credits.

Platforms

Zavu offers API and web access. Its SDKs cover five programming languages, but the product’s API-led design is a better fit for teams able to build than for users seeking a turnkey desktop or mobile help desk.

Who it's for

Zavu suits developers and product teams that need one API for several messaging channels, routing, and customer-specific AI agent workflows. The free plan offers a low-cost way to begin, while Pro expands connections and monthly memory capacity. Teams that want established plug-and-play service integrations, a standard email-first help desk, or predictable outbound sending without prepaid balance management should consider another approach.

Pros and cons

• Pros: Broad messaging-channel support and automatic routing give application builders flexibility over where conversations happen.
• Pros: Agent knowledge bases, memory and customer-owned tools support tailored workflows across messaging and phone.
• Pros: Multiple SDKs, an MCP server, CLI and n8n node provide several integration paths for developers.
• Cons: The free tier limits users to two connections and 2,000 shared monthly messages across four channels.
• Cons: Sending stops when prepaid balance reaches zero, so outbound continuity depends on balance management.
• Cons: Voice starts at $0.07 per minute, with extra charges for premium models and voices and no BYOK option.
• Cons: Several named business integrations remain coming soon, limiting immediate fit for teams that depend on them.

Alternatives

Shared Inbox Software is a useful category starting point for comparing conventional team inbox tools.

Zoho TeamInbox is worth considering for teams seeking shared incoming and outgoing email channels, rules, and internal discussion, with Android and iOS apps as well as web access.

Coherence may suit teams looking for a freemium option with a stated free allowance of three users, 50 shared AI credits per month and 2,500 records.

Help Scout offers a free plan for five users with one Inbox and one Docs site, making it a relevant alternative for a small team wanting those support tools.

Maxdesk is an alternative for teams looking for a free web-based option with unlimited agents and tickets within fair usage.

MailStack may be a better fit for teams seeking a free, self-hosted, single-node reference deployment.

Sharebox offers a free web plan with up to two shared inboxes, unlimited team members, assignment and status tracking.

Cerb is another option to compare for teams considering community or licensed self-hosted software.

Drag is an alternative to consider for teams looking for shared inboxes in Gmail with board views and assignment features.

Verdict

Choose Zavu Inbox if you are building a product or custom workflow that needs multi-channel messaging, routing and agents connected to your own tools. Its breadth and developer access are the main reasons to choose it; the strongest reasons to look elsewhere are the tight free quota, prepaid sending dependency, extra voice costs and integrations that are not yet ready.