Bring Sms Marketing
to OpenAI Agents SDK
Learn how to connect String to OpenAI Agents SDK and start using 10 AI agent tools in minutes. Fully managed, enterprise secure, and ready to use without writing a single line of code.
What is the String MCP Server?
Connect your String account to any AI agent and manage business messaging.
What you can do
- Contact Management — List, view, and create contacts
- Messaging — Send SMS and MMS messages to any phone number
- Conversation Tracking — View message history and active threads
- Campaign Management — List SMS marketing campaigns
- Tag Organization — View contact tags for segmentation
- Health Check — Verify API connectivity
Built-in capabilities (10)
Verify API connectivity
Create a contact
Get contact details
Get message details
List campaigns
List all contacts
List conversations
List messages
List all tags
Send a text message
Why OpenAI Agents SDK?
The OpenAI Agents SDK auto-discovers all 10 tools from String through native MCP integration. Build agents with built-in guardrails, tracing, and handoff patterns. chain multiple agents where one queries String, another analyzes results, and a third generates reports, all orchestrated through Vinkius.
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Native MCP integration via
MCPServerSse, pass the URL and the SDK auto-discovers all tools with full type safety - —
Built-in guardrails, tracing, and handoff patterns let you build production-grade agents without reinventing safety infrastructure
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Lightweight and composable: chain multiple agents and MCP servers in a single pipeline with minimal boilerplate
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First-party OpenAI support ensures optimal compatibility with GPT models for tool calling and structured output
String in OpenAI Agents SDK
String and 3,400+ other MCP servers. One platform. One governance layer.
Teams that connect String to OpenAI Agents SDK through Vinkius don't need to source, host, or maintain individual MCP servers. Every tool call runs inside a hardened runtime with credential isolation, DLP, and a signed audit chain.
Raw MCP | Vinkius | |
|---|---|---|
| Server catalog | Find and host yourself | 3,400+ managed |
| Infrastructure | Self-hosted | Sandboxed V8 isolates |
| Credential handling | Plaintext in config | Vault + runtime injection |
| Data loss prevention | None | Configurable DLP policies |
| Kill switch | None | Global instant shutdown |
| Financial circuit breakers | None | Per-server limits + alerts |
| Audit trail | None | Ed25519 signed logs |
| SIEM log streaming | None | Splunk, Datadog, Webhook |
| Honeytokens | None | Canary alerts on leak |
| Custom domains | Not applicable | DNS challenge verified |
| GDPR compliance | Manual effort | Automated purge + export |
Why teams choose Vinkius for String in OpenAI Agents SDK
The String MCP Server runs on Vinkius-managed infrastructure inside AWS — a purpose-built runtime with per-request V8 isolates, Ed25519 signed audit chains, and sub-40ms cold starts. All 10 tools execute in hardened sandboxes optimized for native MCP execution.
Your AI agents in OpenAI Agents SDK only access the data you authorize, with DLP that blocks sensitive information from ever reaching the model, kill switch for instant shutdown, and up to 60% token savings. Enterprise-grade infrastructure, zero maintenance.

* Every MCP server runs on Vinkius-managed infrastructure inside AWS - a purpose-built runtime with per-request V8 isolates, Ed25519 signed audit chains, and sub-40ms cold starts optimized for native MCP execution. See our infrastructure
How Vinkius secures
String for OpenAI Agents SDK
Every tool call from OpenAI Agents SDK to the String MCP Server is protected by DLP redaction, cryptographic audit chains, V8 sandbox isolation, kill switch, and financial circuit breakers.
Frequently asked questions
Can my AI send text messages?
Yes. Use send_message with the recipient phone number and message text. The agent delivers it via String.
Can I view conversation history?
Yes. list_conversations shows all active threads, and list_messages returns full message history.
Can I create contacts through the AI?
Yes. create_contact adds a new contact with name and phone number to your String directory.
How does the OpenAI Agents SDK connect to MCP?
Use MCPServerSse(url=...) to create a server connection. The SDK auto-discovers all tools and makes them available to your agent with full type information.
Can I use multiple MCP servers in one agent?
Yes. Pass a list of MCPServerSse instances to the agent constructor. The agent can use tools from all connected servers within a single run.
Does the SDK support streaming responses?
Yes. The SDK supports SSE and Streamable HTTP transports, both of which work natively with Vinkius.
MCPServerStreamableHttp not found
Ensure you have the latest version: pip install --upgrade openai-agents
Agent not calling tools
Make sure your prompt explicitly references the task the tools can help with.
