Talon

A terminal UI for DeepSeek Harness (dsh) agents, shipped as a dsh plugin bundle. Talon renders a full interactive session — streaming transcript, tool approvals, user questions, slash commands, and cross-workspace session resume — inside your terminal, on top of an unmodified harness checkout.

中文文档见 README.zh.md.

Features

• Streaming transcript — role headers with plain, copy-friendly text (drag-select copies exact message text), streamed markdown that settles into cached committed cells, context-injection cards, and zero ESC[3J scrollback wipes during normal interaction.
• Approval panel — dsh's first terminal approval UI. When a tool asks for escalation (e.g. a bash command denied by the sandbox retrying with sandbox_permissions), an inline panel shows the tool, the command preview, the cwd, and the justification. 1 allow once, 2 reject, Esc cancel. Every decision leaves a one-line audit entry in the transcript.
• User questions — the model can ask you questions through ask_user_question (composed into the bundle): single- and multi-select options, custom free-form answers, multi-question requests answered serially, and plan-review intents rendered with the approving option highlighted.
• Slash commands — /help, /status, /resume, /clear, /exit, /quit, with fuzzy autocomplete on /. Command results render from durable session events, so a resumed session replays them byte-identically.
• Session resume — /resume opens a selector (type to filter, Tab toggles between this workspace and all workspaces, ISO timestamps, live/persisted markers). Resuming rebinds the UI in-process: the working directory moves first (chdir-first), the transcript replays from the live session log, and the resumed agent can immediately take new turns.
• Clean exit — /exit (or Ctrl+C / Ctrl+D at an empty idle composer) restores the terminal and prints a goodbye line naming the session: To resume: dsh --profile talon, then /resume — session <id>.

Requirements

• Node >= 22.19, pnpm
• A checkout of deepseek-harness as a sibling directory of this repo
• An interactive terminal (talon fails loud off-TTY; use dsh --profile headless for automation)

Install

Either way, build the harness first (dsh is the host talon runs in):

cd deepseek-harness && pnpm install && pnpm run build:lib:host

From npm

Talon is published as talon-ui — no clone, no build, prebuilt lib/ ships in the package:

cd deepseek-harness
pnpm dsh plugin --profile talon add talon-ui
pnpm dsh --profile talon

talon-ui@0.1.0 is verified against the dsh 0.1.1-rc line.

From source (development)

Clone this repo as a sibling of deepseek-harness, build it, and install the profile with a live symlink:

cd talon-ui && pnpm install && pnpm build
cd ../deepseek-harness
pnpm dsh plugin --profile talon add link:../talon-ui

dsh plugin seeds $DSH_HOME/profiles/talon (default ~/.dsh/profiles/talon) with @deepseek-ai/dsh-base and appends talon-ui as a bundle layer. The link: protocol installs a real symlink to this repo, so after any source change pnpm build is all it takes — no profile reinstall. See docs/INSTALL.md for details, including uninstalling and why link: rather than file:.

Usage

cd deepseek-harness
pnpm dsh --profile talon

Keys

Key	When	Action
Enter	composing	send
Shift+Enter	composing	newline
Esc	turn running	interrupt
Ctrl+C	turn running	interrupt
Ctrl+C	idle, text in composer	clear composer
Ctrl+C / Ctrl+D	idle, empty composer	exit
Ctrl+L	anytime	force full redraw

Panels

• Approval: 1 allow once · 2 reject · arrows move the highlight · Enter picks it · Esc cancel.
• Question: ↑/↓ or 1–9 move · Space toggles an option (multi-select) · Tab (or c) switches to a custom free-form answer · Enter submit · Esc cancel (from custom mode: back to options) · PgUp/PgDn page long question headers.
• Resume: type to filter · ↑/↓ move · Tab toggles this-workspace / all-workspaces scope · Enter resume · Esc clears the filter, then closes.

Try it

• Streaming: Explain what this repository does.
• A question: Use ask_user_question to ask me a multi-select question with options Alpha, Bravo, Charlie.
• An approval: Run exactly: touch ~/talon-demo — the sandbox denies writes outside the workspace, the model escalates, and the approval panel appears.
• Resume: /exit, relaunch, /resume, pick the session — the transcript replays and the agent continues where it left off, even from a different working directory.

Development

pnpm test        # vitest, v8 coverage, per-file 100% thresholds on src/
pnpm typecheck   # tsc strict against the harness checkout's built declarations
pnpm build       # emits lib/ (what the linked profile actually runs)
pnpm test:e2e    # live PTY smoke: boot → stream → approval escalation → goodbye

pnpm test:e2e drives a real pnpm dsh --profile talon session on a PTY against the live model. It needs the built harness, the link:-installed talon profile, DEEPSEEK_API_KEY, and python3; when anything is missing the suite skips itself, and the default pnpm test never runs it. The approval phase creates and removes ~/.talon-e2e-<pid>.

Design documents live under docs/: the design spec in docs/specs/ and per-milestone implementation plans in docs/plans/.

Architecture

Two cordis plugins plus a bundle patch:

• talon-ui/boot (talon-boot) — host side: creates the root agent with the composition's default model selection. The UI plugin never owns the agent (dedicated-front-door design).
• talon-ui — the UI: mounts the controller on a real TTY, renders through pi-tui, and consumes dsh strictly through narrow service facets (approval responder, question provider, command registry, session query, agent registry).
• cordis.patch.yml — the bundle layer composed on top of @deepseek-ai/dsh-base: storage + session-projection cache (cheap session titles for the resume selector), dsh-tool-ask-user (the model-facing question tool), and the two talon rows.

Rendering follows an event-driven, replay-identical discipline: everything the transcript shows comes from durable session events, so a live session and its later resume render the same bytes. Untrusted strings (model text, tool output, titles) pass a sanitizer before styling; committed cells cache their rendered lines and only mutating state invalidates them.

Status

Milestones T0 (skeleton), T1 (core loop), and T2 (rich interaction: approvals, questions, commands, resume) are complete and covered by unit, snapshot, and live PTY tests. Next up: T3 (rich rendering — markdown highlighting, tool cards, diffs) and T4 (polish — model picker, @file completion, notifications, image paste, Windows).

License

MIT