Spanly
Observability platform built specifically for Model Context Protocol servers and traffic monitoring.
What is Spanly?
Spanly serves as a specialized layer for observing Model Context Protocol interactions in production environments. It captures full JSON-RPC payloads, timings, and errors across any language or transport method, allowing teams to inspect failing tool calls and resource reads in detail. This complements existing application performance tools by focusing on MCP-shaped data that standard APM solutions often overlook. The service supports real-time dashboards, version-aware performance breakdowns, and client-specific analytics to identify bottlenecks or problematic deployments quickly. With options for data residency in US or EU regions and an emphasis on zero-overhead integration via CLI wrappers or lightweight SDKs, it enables engineering teams to maintain visibility into their MCP infrastructure at scale. By providing aggregated usage metrics, automated error grouping, and always-on status views, Spanly helps on-call responders correlate issues across servers and clients while preserving full data residency and compliance features.
Key features
What you can use Spanly for
Production MCP Server Monitoring
Capture every tool call, prompt, and resource request across MCP servers with full JSON-RPC payloads, timings, and error details without modifying server code.
Error Tracking and Debugging
Automatically group recurring MCP errors by code and context so on-call engineers can inspect failing tool calls and responses in one place.
Performance and Usage Analytics
Track p50/p95/p99 latencies per tool or prompt, identify slow operations, and analyze usage trends across different clients and server versions.
How to use Spanly
- 1Install the CLI with the provided one-line script
- 2Wrap your MCP server process using the CLI or add the SDK
- 3Start the server and send traffic from any MCP client
- 4View live traces, errors, and performance metrics in the Spanly dashboard
Spanly pricing
Pricing model: Freemium. Plan details are indicative — check the site for current prices.
Free
- Free tier, no credit card
- Open-source SDK & CLI on GitHub
Business
Popular- 50% off for 12 months via Founding Partner Program
Editor's verdict
Pros
- +Works with any language and transport without modifying server code
- +Complements existing APM tools like Datadog, Sentry or New Relic
- +Per-client and per-tenant views with full data residency options
Cons
- –MCP-specific focus may require separate tooling for non-MCP traffic
- –Newer product with emphasis on early-adopter founding partner program
Our take: Spanly is a solid coding & dev choice. It's valued for works with any language and transport without modifying server code and complements existing apm tools like datadog, sentry or new relic. The main trade-off is mcp-specific focus may require separate tooling for non-mcp traffic. A good pick if you want capable AI without a high upfront cost.
Frequently asked questions
Spanly is a dedicated observability layer for Model Context Protocol (MCP) traffic that captures requests, responses, errors, and performance metrics at the protocol level.
Summary
Spanly is a solid coding & dev choice. It's valued for works with any language and transport without modifying server code and complements existing apm tools like datadog, sentry or new relic. The main trade-off is mcp-specific focus may require separate tooling for non-mcp traffic. A good pick if you want capable AI without a high upfront cost.
User reviews
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