Module mcp_observed 

The MCP servers each agent’s CLI says it has, per pane: what Connectors shows, as opposed to what AgentMux wrote into the agent’s .mcp.json (SPEC_CONNECTORS_MCP_WHAT_AGENTS_RUN_2026_10_10.md §3).

Claude Code’s system/init frame lists every MCP server it loaded, from every source, with a status and the CLI’s own source label: {"name":"stub","status":"connected","source":"project"}. The label is project (.mcp.json, which is where AgentMux’s servers go), user (the account’s config), local, dynamic (--mcp-config, plugins), managed, enterprise or claudeai (claude.ai connectors). Its tool list names each server’s tools mcp__<server>__<tool>, the server name with everything but letters, digits, _ and - made _. Checked against the real CLI by scripts/cli-contract/mcp-servers-contract.mjs.

Only names, statuses and counts: the frame carries no server config, so nothing secret passes through here. The health of the agentmux entry and its repair are mcp_health’s; this only records.

Each report belongs to the spawn that sent it, by the spawn’s process-wide registration nonce (persistent::next_registration_nonce), which only grows. A report is kept only over one from an older or the same spawn, and a spawn’s exit clears only its own: so a replaced process, even one of a replaced controller whose spawn_generation restarted, never writes over or clears a newer process’s servers. A spawn that has exited records nothing more: its reader can still be running after the exit is handled (an abort doesn’t stop it mid-poll), and a late report would stay with nothing left to clear it.

Structs

Observation

The servers one pane’s CLI last reported, and when.

ObservedServer

One MCP server as the agent’s CLI reported it.

State 🔒

Constants

MAX_ENDED 🔒

At most this many panes’ exit markers (State::ended) are kept, the oldest spawns going first: a marker matters only while its reader may still be finishing, seconds after the exit.

Statics

OBSERVED 🔒

Functions

all

Every pane’s last report, by block id.

forget_owned

Spawn owner exited: drop its report, or an older spawn’s still shown (a replacement that exits before reporting leaves its predecessor’s), never a newer spawn’s; and keep none it sends later. True when there was one to drop.

observed 🔒

parse_init

The servers in an init frame, or None when it has no mcp_servers (not an init frame, or another provider’s).

prune

Drop everything kept for panes whose block is gone (exists says which still are): their reports, and their exit markers.

publish

Tell the panes a report changed or went (mcp:observed).

record

Keep what spawn owner of a pane reported, unless a newer spawn already reported or this one has exited. True when it changed, so the caller tells the panes (mcp:observed); a resumed turn’s init repeats it.

record_init

Record an init frame’s servers for spawn owner. True when they changed: the caller then publishes (publish).

tool_prefix 🔒

The prefix of a server’s tool names in the CLI’s tool list.