AgentCat v2.0.1 — FastMCP Code Mode support

AgentCat now fully supports servers built on FastMCP Code Mode — and, more generally, any server that calls itself mid-request: catalog meta-tools fetching the hidden catalog, sandboxes chaining tools through call_tool, one tool composing another.

The bug this fixes

Code Mode's meta-tools fetch the real tool catalog from inside a tools/call (fastmcp's CatalogTransform.get_tool_catalog, which lists with run_middleware=True). That mid-call listing re-entered AgentCat's injection pass and rebuilt the strip registries from the raw backend catalog — replacing the agent-facing ones. On any Code Mode server:

• Broken calls: after the first execute, the injected session_id/context arguments were no longer stripped, so an agent echoing the handle it was just issued failed FastMCP validation with Unexpected keyword argument on every subsequent call.
• The outer call's structured _mcp_instructions mirror was silently dropped.

Separately, inner sandbox calls each minted their own session — fragmenting one logical execute across several — and their results carried mint-back decoration into the sandbox, where generated code trips over the extra key.

What v2.0.1 does

The community adapter now distinguishes agent-facing traffic from server-internal traffic. While a tracked call is in flight:

• A nested tools/list is served verbatim — no injection, no registry writes. Agent-facing registries survive, and sandbox-facing catalogs stay clean.
• A nested tools/call is still tracked — you get per-tool analytics inside Code Mode blocks — but it joins the enclosing call's session (one execute, one session), carries the new presence-gated agentcat_nested: "true" tag, and is never decorated, so your tool code always sees your own data.

agentcat_session_id_source keeps the outer call's value on nested events, so existing dashboards, queries, and exporter pipelines are unaffected; nested events are filterable via the new tag.

Verified across the supported matrix — mcp 1.x with fastmcp 3.0.0 through 3.4.5, mcp 2.x with fastmcp 4.0.0b1 — including end to end over streamable HTTP against a live Code Mode server.

Full Changelog: v2.0.0...v2.0.1