title: MCP Servers description: External MCP server health and traffic - latency by transport, OAuth state across servers, lifecycle events, transport mix, server status timeline.

MCP Servers

MCP Servers - Servers up 1 / 1 and OAuth authorized 1 reflect the built-in spring-ai-playground-built-in-mcp server registered over streamable-http. Tool-call volume bars surface as soon as an external MCP catalog entry is activated and the agent reaches a tool through it.

Purpose - external MCP server health and traffic. Latency by transport, OAuth state across servers, lifecycle events.

When to look here

• "Is one MCP server slow?" - Latency p50 / p95 / p99 stacked by transport; Top servers identifies which one carries the most traffic.
• "Did an OAuth token expire silently?" - OAuth expiring <5 min KPI + the OAuth status grid below.
• "Is the agent reaching a server that crashed?" - Servers up vs MCP servers KPI gap (e.g. 3 / 5 is two servers down).
• "Which transport family dominates?" - Transport mix donut (stdio / streamable-http / sse).
• "Did the lifecycle behave abnormally?" - Lifecycle events by transport class chart (initialize / shutdown / etc.).

Span filter

spring.ai.tool spans where mcp.method.name is present.

Each such span is enriched by McpToolObservationFilter with risk and composition dimensions lifted from the call's MDC context: saip.tool.origin (internal_js / wrapped_external), saip.composition.id / .name, saip.tool.exposed_alias, saip.mcp.server (the upstream server name), the three risk levels saip.risk.final / .server / .publish, and saip.risk.floor_trigger when a floor rule tripped. So a tool re-exposed through composition is traceable back to its upstream server and its computed risk - not just its exposed alias.

Controls

All dashboards share the Observability global settings - time window, refresh interval, custom range. MCP Servers has no tab-specific controls beyond those.

KPI cards - Volume & Quality (six)

Card	Shows	Source
MCP servers	Number of registered external MCP servers	McpClientService.registeredServers().size()
Servers up	Number with last connection state OK	Live ping / connection state
MCP tool calls	Count of all externally-routed tool calls	Spans with mcp.method.name non-null
Distinct tools	Unique tool names called externally	set(spring.ai.tool.definition.name) filtered
p95 latency	95th-percentile external tool duration	Span duration distribution
Error rate	Percentage of external calls with status=ERROR	Span status

KPI cards - OAuth State (four)

Card	Shows	Source
OAuth authorized	Count of OAuth-protected servers currently in authorized state	McpServerInfo.oauthStatus
OAuth awaiting	Count awaiting authorization (user-driven OAuth dance not yet completed)	OAuth state machine
OAuth errored / offline	Count where OAuth flow has errored or the server is unreachable	OAuth state machine + ping
OAuth expiring < 5 min	Token-refresh urgency - these will fail soon if not refreshed	Token expiry timestamp

Charts (seven)

Chart	Type	Reading
MCP calls / minute	Line per transport, stacked	Drop to zero on one transport → that transport class lost connectivity
Latency p50 / p95 / p99	Multi-line, ms (one per transport)	stdio is consistently faster (no network); HTTP variants show round-trip cost
Top servers	Horizontal bar, by call count	Identifies the server carrying the most traffic
Top MCP tools	Horizontal bar, by call count	Same question scoped to specific tool names across servers
Transport mix	Donut (stdio / streamable-http / sse)	Sanity check against expected routing
Server status	Stacked bar over time (OK / Error / Awaiting)	Spot a server flipping in/out of healthy state
Lifecycle events by transport class	Bar	Unusual shutdown cluster → server crash loop

Tables

OAuth status grid - Server · Transport · Status · ... - sorted by Status; expiring tokens highlighted. Click a row to navigate to the MCP Server connection page where you can re-authorize.

Cross-references

• MCP Server (feature) - how external MCP servers are registered + the Inspector built-in to Spring AI Playground
• MCP Inspector - sibling tab for MCP primitive operations (read tools, read resources, etc.) rather than tool execution
• Tool Studio - sibling tab for the same shape of data, locally executed
• Observability Architecture → Tool and MCP observability - mcp.method.name discriminator