Crate mnml_bridge 

mnml-bridge — Mount protocol for mnml sibling tools

Bridge / Mount is the integration layer that lets sibling tools (mnml-db-postgres, mnml-forge-bitbucket, …) render their UI as a first-class pane inside mnml — owning the activity-bar icon, the rail content, and the editor body — instead of running as a plain Pty pane.

The four tiers

1. Env vars — every Pty mnml spawns sees MNML_WORKSPACE, MNML_THEME, and MNML_IPC_DIR. Zero protocol; just read on startup. (Available today for any sibling.)
2. JSONL sibling → host — sibling writes JSONL commands to $MNML_IPC_DIR/command; mnml ingests them. toast, open-pty, open (file), more coming. One-way.
3. mnml-bridge SDK — this crate. Typed Rust API around tiers 1 + 2, plus the Mount protocol below.
4. Mount — sibling connects to a Unix-socket-per-mount, streams cell+style frames back, receives input events. Owns rail + body areas of an activity-bar section.

Wire shape

Length-prefixed JSON. Every message is a Frame or Input. The 4-byte little-endian length precedes the JSON body so framing is trivial (no streaming JSON parser needed).

Host → Sibling:

• MountHello { cols, rows } first
• Resize { cols, rows } on terminal resize
• Input { event } on every routed key / mouse event

Sibling → Host:

• Frame { cells: Vec<Vec<Cell>> } whenever the sibling has a new screen state. Cell-perfect; the host stamps these into its own ratatui frame.

V1 keeps it simple: full frames, no diffing. A ~24x80 panel is ~2 KB of JSON; serialization cost is negligible vs ratatui’s own draw cycle.

Re-exports

pub use install::ChipSpec;

pub use install::CommandSpec;

pub use install::ContextMenuEntry;

pub use install::IntegrationSpec;

pub use install::MenuBarEntry;

pub use install::NotificationsSpec;

pub use install::OsNotifyPolicy;

pub use install::Requires;

pub use install::SettingsPage;

pub use install::StatuslineSpec;

pub use install::install_integration;

pub use install::integration_manifest_path;

pub use install::list_installed_integrations;

pub use install::uninstall_integration;

pub use ipc::NotifyOpts;

pub use ipc::ProgressStatus;

pub use ipc::SegmentSide;

pub use ipc::ToastLevel;

pub use ipc::notify;

pub use ipc::progress_end;

pub use ipc::progress_start;

pub use ipc::progress_update;

pub use ipc::register_command;

pub use ipc::set_activity_badge;

pub use ipc::statusline_clear_segment;

pub use ipc::statusline_set_segment;

pub use ipc::toast;

pub use ipc::toast_dismiss;

pub use ipc::toast_error;

pub use ipc::toast_info;

pub use ipc::toast_persistent;

pub use ipc::toast_warn;

Modules

install

Integration manifest install helpers — sibling-authored self-registration for the rail chip, palette commands, chord bindings, context menu additions, menu-bar entries, statusline segments, settings pages, and OS notification policy. Writes a single TOML file per integration:

ipc

Tier-2 IPC helpers — write JSONL commands to the host.

modifier

Bitflags for Cell::modifiers. Mirrors ratatui’s Modifier constants so a sibling can reuse its existing styling.

Structs

Cell

A single terminal cell — one grapheme + style. Mirrors ratatui’s buffer::Cell shape but with serde derived.

Geometry

Sent by the host once on connection, then on every terminal resize.

Enums

HostMessage

Host → sibling messages.

InputEvent

Routed input event from the host. Key / mouse events that happened inside the mount’s area are forwarded as-is.

RgbOrIndex

Either a true-color RGB triple or a 256-color palette index.

SiblingMessage

Sibling → host messages.

Functions

read_message

Read a length-prefixed JSON message from a stream.

write_message

Write a length-prefixed JSON message to a stream.