hephaestus/docs/reference/heph-nvim.md

---
title: heph.nvim
modified: 2026-06-03
tags:
  - reference
  - design
---

# heph.nvim

The Neovim knowledge-base surface (tech-spec §8): a plugin that replaces
obsidian.nvim and is a **thin client of the local `hephd`** over its
unix-socket JSON-RPC. Notes, journals, and tasks are edited as ordinary
buffers; the daemon owns all storage and sync.

> **Repo:** the plugin code lives in its own forge repo,
> [eblume/hephaestus.nvim](ssh://forgejo@forge.ops.eblu.me:2222/eblume/hephaestus.nvim.git)
> (extracted from this monorepo). This card documents the surface's
> architecture; see [[install-heph]] to install it and the plugin repo for the
> Lua sources + headless e2e suite.

## Architecture

The `lua/heph/` modules, each small and single-purpose:

| Module | Responsibility |
|---|---|
| `rpc` | libuv (`vim.uv`) unix-socket JSON-RPC client. A blocking `call()` is built over the async pipe by pumping the loop with `vim.wait` until the matching id returns. Demuxes responses by id; partial lines are buffered; JSON `null` decodes to Lua `nil` (`luanil`). A `Session` is one connection — the module keeps a default singleton and lets tests open isolated sessions. |
| `node` | Buffer-backed nodes. A node is a buffer named `heph://node/<id>` with `buftype=acwrite`; `BufReadCmd` loads the body via `node.get`, `BufWriteCmd` saves the whole buffer via `node.update`. |
| `link` | Parse the `[[wiki-link]]` under the cursor (mirroring `extract.rs` grammar) and follow it via `node.resolve` (exact, never fuzzy `search`). Unresolved links are allowed. |
| `journal` | Open/create a dated journal node (idempotent — deterministic id). |
| `config` / `init` | `setup(opts)`, socket resolution, default keymaps. The plugin is **connect-only** — it never spawns a daemon (see Daemon lifecycle). |
| `command` | The `:Heph <subcommand>` dispatch + completion. |

Surfaces never touch SQLite — every operation is a daemon RPC (tech-spec §3).
The plugin is **mode-agnostic**: Tactical/Strategic/Organizational are
plugin-side compositions of daemon primitives, not daemon concepts.

## Daemon lifecycle

The plugin is **connect-only**: it never spawns or supervises a `hephd`. The
daemon is an explicit, OS-managed service started once with **`heph daemon
start`** (a launchd agent on macOS, a systemd user service on Linux — see
[[run-the-daemon]]); every surface (CLI, TUI, this plugin) is a pure client of
that one daemon. On `setup({})` the plugin resolves the socket and connects; if
nothing is serving it, it notifies once with guidance to run `heph daemon
start` (and a dropped connection is retried with a plain reconnect — never a
spawn). The `$HEPH_SOCKET` / `$HEPH_DB` env knobs (and `mise run dev`) point a
dev Neovim at a separate daemon + DB so real data is never touched.

> **History:** earlier iterations had the plugin auto-spawn and supervise its
> own daemon (`autostart`, self-heal, kill-on-exit). That was removed once the
> CLI became a first-class surface — a daemon owned by one surface can't be
> shared, so lifecycle moved to an explicit service ([[design]] §4).

## Daemon RPC dependencies

Beyond the existing methods (tech-spec §6), the plugin relies on
**`node.resolve {title} → Node | null`**: an exact, owner-scoped,
non-tombstoned alias-then-title match — the same mapping the store uses to
materialize `wiki` links, so "follow link under cursor" jumps to the *same*
node the stored link points at. When the target doesn't resolve, follow
**creates** a `doc` with that title (the zettelkasten follow-or-create gesture)
and materializes the source's backlink (saving the source if it has unsaved
edits, else adding the `wiki` link directly).

## Commands (as of slice 11c)

| Command | Action |
|---|---|
| `:Heph home` | Open the home / index landing page (created on first use; title via `opts.home`) |
| `:Heph today` / `:Heph journal <YYYY-MM-DD>` | Open today's / a dated journal |
| `:Heph journals` | Pick among recent days (preview existing, `@create` for new); count via `opts.journal_days` |
| `:Heph follow` (also `<CR>` in a node buffer) | Follow the `[[link]]` under the cursor — **creating** the target doc if it doesn't exist yet |
| `:Heph doc <title>` | Create (and open) a new wiki doc |
| `:Heph open <id>` | Open a node buffer by id |
| `:Heph search <query>` | Full-text search; pick a result to open |
| `:Heph next [scope]` | Tactical "what is next?" view (`<CR>` opens a task's context) |
| `:Heph list [attention]` | Organizational survey of the outstanding set |
| `:Heph view <name>` | Run a built-in filter view (`tom\|ondeck\|chores\|work\|tasks`, tech-spec §8.2) |
| `:Heph capture <title>` | Capture a committed task (pick attention) |
| `:Heph attention [color]` | Set the current task's attention |
| `:Heph done` / `:Heph drop` / `:Heph skip` | State change on the current task |
| `:Heph promote [attention]` | Promote the `- [ ]` line under the cursor to a committed task |
| `:Heph log <text>` | Append a breadcrumb to the current task's log |

A node buffer opens with an editable **YAML frontmatter** block on top (`id`,
`kind`, `title`, `tags`, and — for a task or its context doc — the task's
`state`/`attention`/`do_date`/`late_on`/`recurrence`/`project` plus a `task:`
ref). On `:w`, `frontmatter.lua` diffs the block against what was rendered and
issues the right RPC per changed field (rename, `set_attention`, `set_schedule`,
`set_project`, `tag.add`/`tag.remove`); the store strips the block so it never
enters the body (tech-spec §8.3). A buffer with no block edits no metadata.

"Current task" is resolved from the buffer: a `task` node, or a canonical-context
doc whose owning task is followed via its `canonical-context` backlink. The
`next`/`list` views render the titled rows the daemon returns (`list` enriched to
carry titles + the context id, so no N+1 `node.get`) and are **interactive**:
`<CR>` opens a task's context, `a` adds a task (prompt title + attention), `d`
marks the task under the cursor done, `r` refreshes. Each row also shows a
compact **do/late date chip** (and a recurrence `↻`). Pickers use built-in
`vim.ui.select`, auto-upgrading to Telescope when installed.

**Promotion** (`:Heph promote`) mints a committed task from the `- [ ]` line
under the cursor (the daemon's `task.promote`, `item_ref` = the cursor item's
1-based index among context items, computed code-fence-aware to mirror
`extract.rs`) and rewrites that line into a `[[link]]` to the new task. To keep
that link unambiguous, wiki-link resolution excludes canonical-context docs, so
`[[Task Title]]` resolves to the task, not its identically-titled context doc.

## Testing (tech-spec §9)

The headless e2e suite drives the plugin in `nvim --headless` against a real
`hephd` over a temp socket, asserting both buffer contents and resulting DB
state (via an isolated RPC session). It uses a **self-contained busted-style
runner** (`tests/e2e/runner.lua`) — no external plugins, no network — so it is
deterministic. The suite lives in the plugin repo (eblume/hephaestus.nvim); since
that repo carries no Rust source, `mise run test-nvim` there drives the suite
against a prebuilt `hephd` supplied via `$HEPHD_BIN` (built from this monorepo:
`cargo build -p hephd`). A deliberately failing spec exits non-zero, and the
runner also fails if it discovers zero specs — no false-green.

## Related

- [[v1-prototype-tech-spec]] — §8 surface spec, §6 RPC API, §9 testing strategy
- [[design]] — the mode model (Tactical/Strategic/Organizational) and rationale