dsh-composer-input-history

dsh-composer-input-history

Shell-style input history for the DeepSeek Harness Web composer — the behaviour you know from opencode and other terminal agents.

Press ↑ in the composer to pull back a message you already sent in this Session. Press ↓ to walk forward again; past the newest message your original draft comes back, and one more ↓ discards it and clears the composer.

What it does

History is what you sent in this Session, oldest to newest, read from the Chat node store the view itself renders (snapshot.nodes, ordered by anchor sequence): ordinary user messages, steering messages, and the message that woke a turn. Skipped: hidden nodes (compacted or interrupted), attachment-only messages, and everything the Harness authors on your behalf — goal rounds, skill catalogs, runtime snapshots, job notices, model notices, approval answers, and compaction checkpoints. The visible window is also persisted per Session in localStorage (capped at 300 entries) and merged with the live store, so messages a compaction pruned stay recallable, including after a restart.

Why it is a keyboard observer

The Harness composer deliberately leaves ↑/↓ to its shell-owned Lexical editor, so no slot or command seam owns them. This plugin therefore:

• registers an invisible Session-scoped occupant in conversation.composer.dock;
• reads the Session's Chat nodes through the standard useChat hook (snapshot.nodes) and the draft through the standard useInput hook;
• writes the recalled text through the standard inputActions.setDraft API, so the edit stays part of the composer's own draft history;
• watches the key on two paths: a document-level keydown listener and the shortcuts service's observeFixedInput seam. The document listener runs after the composer's own keymap, so a slash menu or an IME that already handled the key still wins; the fixed-input seam covers compositions where a native Desktop adapter owns the DOM feed. Exactly one path acts, because the first one to act cancels the event.

Replacing a draft commits paragraph by paragraph, so intermediate empty or partial drafts are expected; the plugin treats a published draft that matches what it wrote (ignoring whitespace) as its own and keeps browse mode. Only a genuinely visible slash/reference menu (a mounted role="listbox"), an IME composition, or a held modifier keeps the key — a caret move the editor already marked as handled does not. Editing keys (Backspace, Delete, Enter, printable characters, Ctrl+V/Ctrl+X) end browse mode; navigation keys and shortcuts such as Ctrl+C do not. The browse state machine itself is cached per composer editor element, so re-rendering or remounting the dock entry never drops the browse state or the remembered draft, and starting browse again from an already-recalled message never overwrites the draft you were writing — walking past the newest message always lands on that draft, a blank composer included. When the host re-seeds a stale stored draft over a restore, the plugin re-asserts the restored text (the counter-punch yields only to genuine text editing, not to arrow keys), and every handled key re-arms that defense for the text it just published.

A key is declined when an open menu owns it, when an IME is composing, when a modifier is held, when the event is outside the composer editor, or when the composer is submitting/adjudicating. The plugin imports no Harness Client package and styles nothing.

Install

From npm (short form):

dsh plugin --profile web add dsh-composer-input-history

Or straight from this repository:

dsh plugin --profile web add https://github.com/liumorrisclaw/dsh-composer-input-history

You can also add it in the Web UI's Plugins page, or list the package directory with the plugin manager. The bundle ships off until the profile selects it.

For a local checkout, install by path:

dsh plugin --profile web add /absolute/path/to/dsh-composer-input-history

Relationship to other plugins

The npm name dsh-input-history is already taken by a different community plugin that also recalls prompts with ↑/↓. The two differ in mechanism and behaviour:

Pick this one if you want recall driven by the conversation you can see, including from a draft you are already typing.

Compatibility

Developed and verified against @deepseek-ai/dsh 0.2.0-rc.2. The plugin uses only documented seams: ctx.slots, the Session standard props (useChat, useInput, inputActions), ctx.shortcuts.observeFixedInput, and the activation context's uiSession binding source (declared in dsh.client.inject). It declares dsh.client.inject on dsh-client-ui-conversation, dsh-client-ui-chat, and dsh-client-shortcuts so activation order is deterministic.

Verified

• 48 tests (npm test): 40 unit tests over the pure history reader, the browse navigator, and keystroke arbitration, plus 6 simulated-composer integration tests that mount the real bundle against a stub React host and stub DOM — whole-draft publish, the stale-draft refill and its counter-punch, compaction pruning merged with the persistent record, manual edits, menu yields, and IME declines.
• The composed profile contains the bundle row (dsh --profile <name> --dump-config).
• The browser boot graph announces the bundle with its inject list and immediately: true, and the web host serves the bundle body byte-for-byte.
• End-to-end in a real harness Web instance driven over the DevTools protocol: the dock entry mounts in a session composer, ↑ recalls the sent message, walking down lands on the draft and a further ↓ clears it, a typed draft survives rapid up/down walks, and the console stays clean.
• Recalling a message with ↑ was confirmed by hand in a running Desktop composer.

Limitations

• History is per Session. Cross-session recall (recent Sessions' inputs) is not implemented yet.
• History reflects the loaded transcript window plus the persisted per-Session record; a message never seen by this plugin (sent while it was uninstalled) is not recalled.
• The recalled text is plain text: reference chips and attachments from the original message are not restored.
• One resident composer per Web page is assumed, matching the shell's own design.
• On the home screen (no Session open) there is no recall: the composer dock only renders inside a session.

License

MIT