Crate nexus_core 

nexus-chat-core (lib crate nexus_core): the engine behind the nexus TUI and (later) the nexus host API. Owns all domain logic — sessions, research pipeline, provider clients, tools, files, skills, SQLite state — with no knowledge of the terminal UI. Phase 2e moved every piece of view state (composer, popup chrome, render caches, theme) into the TUI crate’s AppView.

Doc-lint allows: the domain surface the TUI/CLI/host drive directly (Db, provider, config, App’s event handlers) is still pub, so the per-item doc lints would be noise until the Phase 4 host API pass privatizes it. They’re crate-scoped deliberately — the 2e goal (zero TUI deps) is unaffected.

Modules

app

app_templates

Embedded starter scaffolds for the app tool’s init action.

appserver

Tiny always-on static file server for model-created apps. Serves GET /<space>/<app>/<path…> from spaces/<space>/apps/<app>/<path…>, localhost only, GET/HEAD only. Hand-rolled on tokio — no framework dep for ~150 lines of static serving.

citations

Pure parsing for report citations: the trailing Sources: (or ## Sources) list research/web-mode replies end with (see WRITER_PROMPT/SEARCHER_PROMPT in app/research.rs and web_mode_clause in app/chat.rs), and the [n] inline markers that reference it. Parsing is data — it lives here in core. Styling the markers into terminal colors is rendering — it lives in the TUI crate (ui/citations_style.rs).

config

db

extract

Import-time text extraction for space filesets: plain text as-is, PDF via pdf-extract, office formats (pptx/docx/xlsx) by scanning their zipped XML for text tags — same string-scanning style as tools.rs’s DDG HTML parser.

host

Phase 4 nexus host — the daemon surface.

markdown

Plain-text markdown helpers for the core crate: to_plain (markers stripped, for clipboard copy) and the GFM pipe-table splitter shared with the TUI’s styled renderer (crates/tui/src/ui/markdown.rs). This module is deliberately free of ratatui/tui-markdown — styled rendering lives in the TUI crate.

provider

skills

Agent Skills on disk.

space

sync

Phase 3 merge engine: changeset build/apply, per-table sync rules, cursor + ack bookkeeping, and the file blob channel.

tools

Tools the model can call mid-response, advertised as nine consolidated names (batch, skills, scripts, search, fetch_url, research_lookup, files, app, media) that dispatch onto a larger set of specialized implementations below. Concrete (no trait) — there’s exactly one implementation and no need for one yet.

update

Startup update check + auto-update: compare the running version against the latest release on crates.io and, when a newer one exists, install it via cargo install in a detached background process so the TUI boots immediately and the new binary is live on the next launch. Best-effort by design — any failure (offline, index hiccup, missing cargo) is silent or falls back to a plain notice; the app never blocks or fails startup on it. NEXUS_NO_UPDATE=1 opts out of the auto-install.

Functions

boot

One bootstrap for every frontend (TUI, CLI, Phase 4 host): credentials → space → db → appserver → toolbox. This is what main.rs and cli.rs::build_app both used to hand-roll.