Engineering and product notes from the Spanly team.
Researchers turned a public Sentry DSN into remote code execution by hiding shell commands in an error report. How agentjacking works, why no single tool can filter it away, and how MCP observability surfaces the read-to-exec pivot it leaves behind.
The MCP Python SDK now ships OpenTelemetry tracing per SEP-414. It answers a different question than packet-level MCP observability does. Here is what the spans capture, what they leave out, and how traceparent ties the two together.
If your MCP server is part of an AI system in scope of the EU AI Act, logging and traceability are not optional. A practical look at what that means for tool calls, and a checklist.
A practical guide to monitoring an MCP server in production: what to instrument, which metrics matter, and how to set up alerting for tool calls, sessions, and clients.
APM vendors are adding MCP support, and it helps. Here is what their SDK-based coverage gets you, what it structurally cannot, and why you need both.
Spanly is observability for MCP servers. Two-minute install, MCP-native telemetry, EU and US data residency.
The architecture of Spanly: mindset and reasoning behind our decisions, and the stack we ended up with.
A short note announcing the Spanly engineering blog.
