{"product_id":"callnode-openai-gpt-sms-mms-auto-reply-n8n-workflow","title":"CallNode + OpenAI GPT SMS\/MMS Auto-Reply n8n Workflow","description":"\u003ch3\u003eInstant AI SMS\/MMS Auto-Replies from CallNode + OpenAI (n8n Workflow)\u003c\/h3\u003e\n\u003cp\u003eTurn incoming texts into fast, friendly AI responses. This \u003cstrong\u003eCallNode + OpenAI GPT SMS\/MMS Auto-Reply\u003c\/strong\u003e workflow for \u003cstrong\u003en8n\u003c\/strong\u003e automatically reads inbound messages (including optional image context), generates a short reply, and sends it back in the same SMS thread—optionally with an AI-generated image via MMS.\u003c\/p\u003e\n\n\u003ch3\u003eWhat this workflow does\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReceives inbound SMS\/MMS\u003c\/strong\u003e from \u003cstrong\u003eCallNode\u003c\/strong\u003e using a \u003cstrong\u003eheader-authenticated webhook\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUnderstands attached media\u003c\/strong\u003e: if the message includes \u003cstrong\u003emedia URLs\u003c\/strong\u003e, OpenAI analyzes the image(s) and produces a brief description to add context for the reply.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGenerates a short AI response\u003c\/strong\u003e using a business-specific system prompt, keeping \u003cstrong\u003econversation context per sender\/recipient\u003c\/strong\u003e with \u003cstrong\u003ebuffer memory\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSends the reply back to CallNode\u003c\/strong\u003e by returning the generated response as the webhook reply so it’s delivered into the same thread.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHandles image requests\u003c\/strong\u003e: when the response includes an \u003cstrong\u003eimage request marker\u003c\/strong\u003e, OpenAI generates an image, converts it to \u003cstrong\u003ebase64\u003c\/strong\u003e, and sends it as \u003cstrong\u003eMMS\u003c\/strong\u003e via the \u003cstrong\u003eCallNode Messages API\u003c\/strong\u003e using \u003cstrong\u003eHMAC-signed headers\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSupports outbound texting via an n8n form\u003c\/strong\u003e: users can submit a phone number, message, and an optional image URL; the workflow signs and sends it via the CallNode Messages API.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eUse cases\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eAuto-replying to SMS inquiries for a SaaS, agency, or service desk.\u003c\/li\u003e\n  \u003cli\u003eHandling MMS messages that include customer photos (e.g., “Here’s the issue—what now?”).\u003c\/li\u003e\n  \u003cli\u003eGenerating and sending visual content on-demand (e.g., “Send an image of …”) as part of the conversation.\u003c\/li\u003e\n  \u003cli\u003eOperators sending quick outbound updates from an n8n form using CallNode.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical details\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIntegrations\u003c\/strong\u003e: CallNode (inbound webhook + Messages API), OpenAI (chat, image analysis, image generation).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003en8n nodes\u003c\/strong\u003e shown in the workflow: \u003cem\u003ewebhook, form, crypto, if, set, sticky note\u003c\/em\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSecurity\u003c\/strong\u003e: webhook authentication via custom header name\/value; outbound requests signed with \u003cstrong\u003eHMAC\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDeployment setup\u003c\/strong\u003e: create a CallNode number with messaging enabled and configure the inbound webhook URL + matching header authentication to the workflow’s production webhook URL.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"N8N Commerce","offers":[{"title":"Default Title","offer_id":46164216021171,"sku":"N8N-20479","price":14.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0749\/6279\/6723\/files\/xcTUnJGjzGaI1nMDQ9YBd_aIbvAL5f.png?v=1791278345","url":"https:\/\/buyflowscripts.com\/products\/callnode-openai-gpt-sms-mms-auto-reply-n8n-workflow","provider":"N8N Commerce","version":"1.0","type":"link"}