playSMS vs simhook

playSMS is free, open-source SMS management software with a web interface for gateways and bulk SMS services. It sends individual or bulk text, flash, and Unicode messages, and receives private SMS that can be forwarded to email or mobile phones or routed to users and URLs. Built-in tools include automatic replies, polls, quizzes, subscriptions, SMS-to-email, and email-to-SMS through mailbox polling. It connects with Gammu, Kannel, SMS Server Tools, Jasmin, Playnet, Uplink, and several SMS providers. Web services support sending, delivery reports, credit checks, and other operations. Plugins can add features, themes, tools, and gateway modules. Routing can use prefixes or users, with destination-based rating and per-user credits. The project reports one user tested 200,000 SMS per day. playSMS itself cannot send or receive messages without a separate gateway application or service. It is available for Android, Linux, self-hosting, web, and API use under GPLv3 or later, without warranty.

SimHook turns an Android phone with a SIM into an SMS gateway and API for sending and receiving texts. API messages travel through the paired phone, while incoming texts can be forwarded as webhooks. Signed webhooks report sent, delivered, and failed status changes; they are retried for two days and paused if an endpoint keeps failing. The service also supports scheduled sends, multiple recipients, and dual-SIM phones, with a SIM selectable for each message. Its TypeScript SDK supports Node and edge runtimes, and an MCP server provides eight tools for AI agents. API keys can be limited by scope, including a send-only option. The Android app requires Android 8.0 or newer and is distributed as a signed APK. The full stack can be self-hosted from one Compose file under AGPL-3.0, which the maker says is free without limits. Hosted accounts are currently on Free; listed paid plans open soon. The maker says the service is not for bulk marketing or unsolicited texts.