loki/docs/implementation/PHASE-1-STEP-16e-NOTES.md

Phase 1 Step 16e — Implementation Notes

Status

Done.

Plan reference

• Parent plan: docs/implementation/PHASE-1-STEP-16-NOTES.md
• Sub-phase goal: "Switch main.rs and all Config::init() callers to the new flow"

Summary

main.rs and cli/completer.rs no longer call Config::init or Config::init_bare — they use the new flow: Config::load_with_interpolation → AppConfig::from_config → AppState::init → RequestContext::bootstrap.

The bridge Config::to_request_context and the old Config::init are now dead code, gated with #[allow(dead_code)] pending deletion in 16f.

What was changed

New helpers

Config::load_with_interpolation(info_flag: bool) -> Result<Self> in src/config/mod.rs — absorbs the two-pass YAML parse with secret interpolation. Handles:

1. Missing config file (creates via create_config_file if TTY, or load_dynamic from env vars)
2. Reading the raw YAML content
3. Bootstrapping a Vault from the freshly-parsed Config
4. Interpolating secrets
5. Re-parsing Config if interpolation changed anything
6. Sets config.vault (legacy field — deleted in 16f)

config::default_sessions_dir() -> PathBuf and config::list_sessions() -> Vec<String> free functions — provide session listing without needing a Config instance. Used by the session completer.

RequestContext::bootstrap(app: Arc<AppState>, working_mode, info_flag) -> Result<Self> in src/config/request_context.rs — the new entry point for creating the initial RequestContext. Builds:

• Resolved Model from app.config.model_id
• ToolScope.functions cloned from app.functions with append_user_interaction_functions added in REPL mode
• ToolScope.mcp_runtime synced from app.mcp_registry

Made public in Config for new flow

• Config::load_from_file (was fn)
• Config::load_from_str (was fn)
• Config::load_dynamic (was fn)
• config::create_config_file (was async fn)

src/main.rs

Three startup paths rewired:

// Path 1: --authenticate
let cfg = Config::load_with_interpolation(true).await?;
let app_config = AppConfig::from_config(cfg)?;
let (client_name, provider) =
    resolve_oauth_client(client_arg.as_deref(), &app_config.clients)?;
oauth::run_oauth_flow(&*provider, &client_name).await?;

// Path 2: vault flags
let cfg = Config::load_with_interpolation(true).await?;
let app_config = AppConfig::from_config(cfg)?;
let vault = Vault::init(&app_config);
return Vault::handle_vault_flags(cli, &vault);

// Path 3: main
let cfg = Config::load_with_interpolation(info_flag).await?;
let app_config: Arc<AppConfig> = Arc::new(AppConfig::from_config(cfg)?);
let app_state: Arc<AppState> = Arc::new(
    AppState::init(app_config, log_path, start_mcp_servers, abort_signal.clone()).await?
);
let ctx = RequestContext::bootstrap(app_state, working_mode, info_flag)?;

No more Config::init, Config::to_app_config, cfg.mcp_registry, or cfg.to_request_context references in main.rs.

src/cli/completer.rs

Three completers that needed config access updated:

• model_completer → uses new load_app_config_for_completion() helper (runs Config::load_with_interpolation synchronously from the completion context; async via Handle::try_current or a fresh runtime)
• session_completer → uses the new free function list_sessions() (no Config needed)
• secrets_completer → uses Vault::init(&app_config) directly

#[allow(dead_code)] removed

• AppConfig::from_config
• AppConfig::resolve_model
• AppState::init
• AppState.rag_cache (was flagged dead; now wired in)

#[allow(dead_code)] added (temporary, deleted in 16f)

• Config::init_bare — no longer called
• Config::sessions_dir — replaced by free function
• Config::list_sessions — replaced by free function
• Config::to_request_context — replaced by RequestContext::bootstrap

Behavior parity

• main.rs startup now invokes:

  • install_builtins() (installs builtin global tools, agents, macros — same files get copied as before, Step 16b)
  • Config::load_with_interpolation (same YAML loading + secret interpolation as old Config::init)
  • AppConfig::from_config (same env/wrap/docs/user-agent/model resolution as old Config mutations)
  • AppState::init (same vault init + MCP registry startup + global Functions loading as old Config methods, now owned by AppState; also pre-registers initial servers with McpFactory — new behavior that fixes a latent cache miss bug)
  • RequestContext::bootstrap (same initial state as old bridge to_request_context: resolved Model, Functions with REPL extensions, MCP runtime from registry)

• Completer paths now use a lighter-weight config load (no MCP startup) which is appropriate since shell completion isn't supposed to start subprocesses.

Files modified

• src/config/mod.rs — added load_with_interpolation, default_sessions_dir, list_sessions; made 3 methods public; added #[allow(dead_code)] to Config::init_bare, sessions_dir, list_sessions.
• src/config/request_context.rs — added bootstrap.
• src/config/app_config.rs — removed 2 #[allow(dead_code)] gates.
• src/config/app_state.rs — removed 2 #[allow(dead_code)] gates.
• src/config/bridge.rs — added #[allow(dead_code)] to to_request_context.
• src/main.rs — rewired three startup paths.
• src/cli/completer.rs — rewired three completers.

Assumptions made

1. Completer helper runtime handling: The three completers run in a sync context (clap completion). The new load_app_config_for_completion uses Handle::try_current().ok() to detect if a tokio runtime exists; if so, uses block_in_place; otherwise creates a fresh runtime. This matches the old Config::init_bare pattern (which also used block_in_place + block_on).

2. Config::to_request_context kept with #[allow(dead_code)]: It's unused now but 16f deletes it cleanly. Leaving it in place keeps 16e a non-destructive switchover.

3. RequestContext::bootstrap returns Result<Self> not Arc<Self>: caller decides wrapping. main.rs doesn't wrap; the REPL wraps Arc<RwLock<RequestContext>> a few lines later.

4. install_builtin_global_tools added to install_builtins: A function added in user's 16b commit extracted builtin tool installation out of Functions::init into a standalone function. My Step 16b commit that extracted install_builtins missed including this function — fixed in this step.

Verification

• cargo check — clean, zero warnings
• cargo clippy — clean, zero warnings
• cargo test — 122 passing, zero failures
• Grep confirmation:
  • Config::init( — only called from Config::init_bare (which is now dead)
  • Config::init_bare — no external callers (test helper uses #[allow(dead_code)])
  • to_request_context — zero callers outside bridge.rs
  • cfg.mcp_registry / cfg.functions / cfg.vault references in main.rs — zero

Remaining work for Step 16

• 16f: Delete all #[allow(dead_code)] scaffolding:
  • Config::init, Config::init_bare
  • Config::sessions_dir, Config::list_sessions
  • Config::set_wrap, Config::setup_document_loaders, Config::setup_user_agent, Config::load_envs, Config::load_functions, Config::load_mcp_servers, Config::setup_model, Config::set_model, Config::role_like_mut, Config::vault_password_file
  • bridge.rs — delete entirely
  • All #[serde(skip)] runtime fields on Config
  • mod bridge; declaration

After 16f, Config will be a pure serde POJO with only serialized fields and load_from_file / load_from_str / load_dynamic / load_with_interpolation methods.

Migration direction achieved

Before 16e:

main.rs: Config::init → to_app_config → AppState {...} → to_request_context

After 16e:

main.rs:
  install_builtins()
  Config::load_with_interpolation → AppConfig::from_config
  AppState::init(app_config, ...).await
  RequestContext::bootstrap(app_state, working_mode, info_flag)

No more god-init. Each struct owns its initialization. The REST API path is now trivial: skip install_builtins() if not desired, call AppConfig::from_config(yaml_string), call AppState::init(...), create per-request RequestContext as needed.