loki/docs/implementation/PHASE-1-STEP-14-NOTES.md

Phase 1 Step 14 — Implementation Notes

Status

Done.

Plan reference

• Plan: docs/PHASE-1-IMPLEMENTATION-PLAN.md
• Section: "Step 14: Migrate Input constructors and REPL"

Summary

Eliminated GlobalConfig from every file except config/mod.rs (where the type is defined). Input constructors take &RequestContext. REPL holds Arc<RwLock<RequestContext>> instead of GlobalConfig. Reedline components read from shared RequestContext. Sync helpers deleted. to_global_config() deleted. macro_execute takes &mut RequestContext. Implemented RequestContext::use_agent. Added MCP loading spinner, MCP server tab completions, and filtered internal tools from completions.

What was changed

Files modified

• src/config/input.rs — constructors take &RequestContext instead of &GlobalConfig. capture_input_config and resolve_role read from RequestContext/AppConfig.

• src/config/request_context.rs — added use_agent() method. Deleted to_global_config() and sync_mcp_from_registry(). Added MCP loading spinner in rebuild_tool_scope. Added configured MCP servers to .set enabled_mcp_servers completions. Filtered user__*, mcp_*, todo__*, agent__* from .set enabled_tools completions.

• src/repl/mod.rs — Repl struct holds Arc<RwLock<RequestContext>>, no GlobalConfig field. ask and run_repl_command take &mut RequestContext only. Deleted sync_ctx_to_config, sync_config_to_ctx, sync_app_config_to_ctx, reinit_mcp_registry.

• src/repl/completer.rs — holds Arc<RwLock<RequestContext>> instead of GlobalConfig.

• src/repl/prompt.rs — holds Arc<RwLock<RequestContext>> instead of GlobalConfig.

• src/repl/highlighter.rs — updated if it held GlobalConfig.

• src/config/macros.rs — macro_execute takes &mut RequestContext instead of &GlobalConfig.

• src/main.rs — all to_global_config() calls eliminated. Agent path uses ctx.use_agent(). Macro path passes &mut ctx directly.

Methods added

• RequestContext::use_agent(app, name, session, abort_signal) — calls Agent::init, sets up MCP via rebuild_tool_scope, sets agent/rag/supervisor, starts session.

Methods deleted

• RequestContext::to_global_config()
• RequestContext::sync_mcp_from_registry()
• REPL: sync_ctx_to_config, sync_config_to_ctx, sync_app_config_to_ctx, reinit_mcp_registry

UX improvements

• MCP loading spinner restored in rebuild_tool_scope
• .set enabled_mcp_servers<TAB> shows configured servers from mcp.json + mapping aliases
• .set enabled_tools<TAB> hides internal tools (user__*, mcp_*, todo__*, agent__*)

GlobalConfig remaining

Only src/config/mod.rs (13 references): type definition, legacy Config::use_agent, Config::use_session_safely, Config::use_role_safely, Config::update, Config::delete — all dead code. Step 15 deletes them.

Post-implementation review (Oracle)

Oracle reviewed all REPL and CLI flows. Findings:

1. AbortSignal not threaded through rebuild_tool_scope — FIXED. rebuild_tool_scope, bootstrap_tools, use_role, use_session, use_agent, update now all thread the real AbortSignal through to the MCP loading spinner. Ctrl+C properly cancels MCP server loading.

2. RwLock held across await in REPL — KNOWN LIMITATION. Repl::run holds ctx.write() for the duration of run_repl_command. This is safe in the current design because reedline's prompt/completion is synchronous (runs between line reads, before the write lock is taken). Phase 2 should refactor to owned RequestContext + lightweight snapshot for reedline.

3. MCP subprocess leaks — NOT AN ISSUE. rmcp::RunningService has a DropGuard that cancels the tokio cancellation token on Drop. Servers are killed when their Arc<ConnectedServer> refcount hits zero.

4. MCP duplication — NOT AN ISSUE after Step 14. The initial_global sync was removed. MCP runtime is populated only by rebuild_tool_scope → McpFactory::acquire, which deduplicates via Weak references.

5. Agent+session MCP override — PRE-EXISTING behavior, not a regression. When an agent session has its own MCP config, it takes precedence. Supervisor child agents handle this explicitly via populate_agent_mcp_runtime.

6. Stale Input in tool loop — PRE-EXISTING design. Input captures state at construction time and uses merge_tool_results for continuations. Tools communicate results via tool results, not by mutating the session mid-turn. Not a regression.

7. Auto-compression — REPL does inline compression in ask. CLI directive path relies on session save which happens in after_chat_completion. Consistent with pre-migration behavior.

Verification

• cargo check — 6 dead-code warnings (legacy Config methods)
• cargo test — 63 passed, 0 failed