Compatible with every major AI agent and IDE
What is the JustCall MCP Server?
Connect your JustCall account to any AI agent and manage phone communications through natural conversation.
What you can do
- Call Management — Make outbound calls, track call logs with duration and status
- SMS Messaging — Send text messages to contacts and track delivery
- Contact Database — List contacts, create new entries, and inspect profiles
- Call Recordings — Access call recordings with metadata
- Phone Numbers — List available and assigned phone numbers
- Agent Monitoring — Track agent performance, call volumes, and availability
How it works
- Subscribe to this server
- Enter your JustCall API Key and API Secret
- Start managing calls from Claude, Cursor, or any MCP-compatible client
Who is this for?
- Sales Teams — make calls, send follow-up SMS, and track communication history
- Support Teams — manage call queues and monitor agent performance
- Operations — automate phone outreach and SMS campaigns
Built-in capabilities (12)
Create a new contact
Get my profile
Get call details
Get contact details
Get message details
List JustCall numbers
List phone calls
List phone contacts
List SMS/MMS messages
List team members
List active webhooks
Send SMS/MMS
Why CrewAI?
When paired with CrewAI, JustCall becomes a first-class tool in your multi-agent workflows. Each agent in the crew can call JustCall tools autonomously, one agent queries data, another analyzes results, a third compiles reports, all orchestrated through Vinkius with zero configuration overhead.
- —
Multi-agent collaboration lets you decompose complex workflows into specialized roles, one agent researches, another analyzes, a third generates reports, each with access to MCP tools
- —
CrewAI's native MCP integration requires zero adapter code: pass Vinkius Edge URL directly in the
mcpsparameter and agents auto-discover every available tool at runtime - —
Built-in task delegation and shared memory mean agents can pass context between steps without manual state management, enabling multi-hop reasoning across tool calls
- —
Sequential and hierarchical crew patterns map naturally to real-world workflows: enumerate subdomains → analyze DNS history → check WHOIS records → compile findings into actionable reports
JustCall in CrewAI
JustCall and 4,000+ other MCP servers. One platform. One governance layer.
Teams that connect JustCall to CrewAI 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 | 4,000+ 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 JustCall in CrewAI
The JustCall 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 12 tools execute in hardened sandboxes optimized for native MCP execution.
Your AI agents in CrewAI 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
JustCall for CrewAI
Every tool call from CrewAI to the JustCall MCP Server is protected by DLP redaction, cryptographic audit chains, V8 sandbox isolation, kill switch, and financial circuit breakers.
Frequently asked questions
Can I make calls and send SMS through the AI agent?
Yes. Make outbound calls with destination number and track status. Send SMS messages to any contact with delivery tracking. Use contact management tools to find recipient numbers.
Does JustCall require two credentials?
Yes. JustCall uses an API Key and API Secret pair for authentication. Both are sent as Bearer credentials against api.justcall.io/v1.
Can I listen to call recordings and track agent performance?
Yes. Access call recordings with duration and metadata. Monitor agent call volumes, average handle time, and availability status.
How does CrewAI discover and connect to MCP tools?
CrewAI connects to MCP servers lazily. when the crew starts, each agent resolves its MCP URLs and fetches the tool catalog via the standard tools/list method. This means tools are always fresh and reflect the server's current capabilities. No tool schemas need to be hardcoded.
Can different agents in the same crew use different MCP servers?
Yes. Each agent has its own mcps list, so you can assign specific servers to specific roles. For example, a reconnaissance agent might use a domain intelligence server while an analysis agent uses a vulnerability database server.
What happens when an MCP tool call fails during a crew run?
CrewAI wraps tool failures as context for the agent. The LLM receives the error message and can decide to retry with different parameters, fall back to a different tool, or mark the task as partially complete. This resilience is critical for production workflows.
Can CrewAI agents call multiple MCP tools in parallel?
CrewAI agents execute tool calls sequentially within a single reasoning step. However, you can run multiple agents in parallel using process=Process.parallel, each calling different MCP tools concurrently. This is ideal for workflows where separate data sources need to be queried simultaneously.
Can I run CrewAI crews on a schedule (cron)?
Yes. CrewAI crews are standard Python scripts, so you can invoke them via cron, Airflow, Celery, or any task scheduler. The crew.kickoff() method runs synchronously by default, making it straightforward to integrate into existing pipelines.
MCP tools not discovered
Ensure the Edge URL is correct. CrewAI connects lazily when the crew starts. check console output.
Agent not using tools
Make the task description specific. Instead of "do something", say "Use the available tools to list contacts".
Timeout errors
CrewAI has a 10s connection timeout by default. Ensure your network can reach the Edge URL.
Rate limiting or 429 errors
Vinkius enforces per-token rate limits. Check your subscription tier and request quota in the dashboard. Upgrade if you need higher throughput.
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