--- title: "Building Model Context Protocol (MCP) Servers for Telephony and SMS Testing" --- Building Model Context Protocol (MCP) Servers for Telephony and SMS Testing: SMSRiver - [Skip to main content](#main-content) [ smsriver.com ](/) [Public Inboxes](/#numbers-section) [Country Codes](/country-codes/) [Workbench](/workbench/) [Tools](/tools/) [Developer API](/developer/) [Pricing](/pricing/) [Log In](/accounts/login/) [ Log In ](/accounts/login/) [ Get API Key ](/pricing/) [ Home ](/) - [ Articles ](/articles/) - Model Context Protocol & AI Agents Model Context Protocol & AI Agents Published 2026-08-14 • 9 min read # Building Model Context Protocol (MCP) Servers for Telephony and SMS Testing Architectural guide to Model Context Protocol (MCP) for telephony. Connect Claude Code, Cursor, and AI agents to SMS inboxes via JSON-RPC 2.0. Key Takeaway & Executive Summary Model Context Protocol (MCP) enables LLMs to query available phone numbers, inspect inboxes, and test verification flows autonomously via standardized tools. The Model Context Protocol (MCP), created by Anthropic, establishes an open standard for connecting AI assistants to external developer tools and data sources. This guide details how SMSRiver's native MCP server enables autonomous AI agents (such as Claude Code and Cursor) to interact with phone verification inboxes directly. ## Table of Contents - [ Core MCP Telephony Tools ](#section-1) - [ MCP Configuration for Claude Desktop & Claude Code ](#section-2) - [ Frequently Asked Questions ](#frequently-asked-questions) ## 1 Core MCP Telephony Tools SMSRiver exposes 8 standard MCP tools: 1. list_countries: Query available global country pools and active trunk counts. 2. get_active_numbers: Retrieve provisioned phone numbers for a target country. 3. inspect_inbox: Fetch received SMS messages with sender, timestamp, and body. 4. extract_otp: Parse verification codes and magic links from recent messages. 5. generate_synthetic_sms: Inject simulated carrier events for deterministic testing. 6. calculate_segments: Compute GSM-7 vs UCS-2 billable segment math. 7. validate_webhook_payload: Validate JSON payloads against Twilio/Telnyx schemas. 8. check_system_health: Inspect carrier latency and gateway peering metrics. ## 2 MCP Configuration for Claude Desktop & Claude Code json{ "mcpServers": { "smsriver": { "command": "npx", "args": ["-y", "@smsriver/mcp-server"], "env": { "SMSRIVER_API_KEY": "sk_live_your_api_key_here" } } } } ## Frequently Asked Questions • Model Context Protocol & AI Agents What transport protocols does the SMSRiver MCP server support? SMSRiver supports both local stdio transport (for local CLI coding assistants) and remote Server-Sent Events (SSE) for cloud agent architectures. ## Related Technical Articles & Deep Dives [ Model Context Protocol & AI Agents 8 min read ### Using Claude Code to Automate End-to-End User Signups with SMS Verification ](/articles/claude-code-sms-verification-automation/) [ Model Context Protocol & AI Agents 7 min read ### Connecting Cursor AI to Inbound Phone Pools via Model Context Protocol ](/articles/cursor-ai-mcp-telephony-tooling/) [ Model Context Protocol & AI Agents 8 min read ### Designing Secure JSON-RPC 2.0 Tools for LLM Telephony Event Inspection ](/articles/json-rpc-telephony-tools-for-llms/) Developer Sandbox ### Automate Inbound SMS & OTP Testing Eliminate flaky 2FA in CI/CD. Access dedicated virtual lines, programmable synthetic SMS webhooks, and Model Context Protocol (MCP) integrations. [ Explore Developer Tiers → ](/pricing/) [ View MCP Setup Guide ](/developer/mcp-setup/) ### Developer Utilities - [ SMS Segment Calculator Calculate segment counts and carrier costs in real time. ](/tools/sms-segment-calculator/) - [ Webhook Payload Validator Verify JSON webhook payloads against provider schemas. ](/tools/webhook-payload-validator/) - [ SMS Delivery Troubleshooter Diagnose carrier filtering and OTP delivery failure. ](/tools/sms-delivery-troubleshooter/) - [ E.164 Phone Number Formatter Format phone numbers into international E.164 standard. ](/tools/phone-number-formatter/) ### Public Verification Numbers - [ United States (+1) View Line → ](/receive-sms/us/) - [ United Kingdom (+44) View Line → ](/receive-sms/gb/) - [ Canada (+1) View Line → ](/receive-sms/ca/) - [ Germany (+49) View Line → ](/receive-sms/de/) Copied to clipboard FULL PACKET INSPECTION SMS ### Line: DE +49 ... Timestamp: Just now Extracted code Copy Code Message Body: Copy Full Message [ Open Live Inbox ](#) smsriver.com Central Office carrier inventory platform & developer SMS verification sandbox. Receive OTP codes instantly with zero SIM card requirement. Public numbers·Live inboxes·Developer tools Public Inboxes - [United States (+1)](/receive-sms/us/) - [United Kingdom (+44)](/receive-sms/gb/) - [Canada (+1)](/receive-sms/ca/) - [Philippines (+63)](/receive-sms/ph/) - [Germany (+49)](/receive-sms/de/) Developer & Tools - [SMS Debugging Workbench](/workbench/) - [Phone Number Inspector](/tools/phone-number-inspector/) - [Bulk Phone Validator](/tools/bulk-phone-validator/) - [Phone Lookup API](/developer/phone-lookup-api/) - [E.164 Phone Formatter](/tools/phone-number-formatter/) - [SMS Segment Calculator](/tools/sms-segment-calculator/) - [Webhook Validator](/tools/webhook-payload-validator/) Guides & Trust - [Country Calling Codes](/country-codes/) - [Troubleshooting Hub](/troubleshooting/) - [Carrier Comparisons](/compare/) - [Developer Reference](/developer/) - [OpenAPI Specification](/openapi.json) - [MCP Tools Manifest](/.well-known/mcp.json) - [Privacy & Security Guides](/guides/) - [Engineering Articles](/articles/) © 2026 SMSRiver. 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