Lark Agent Bridge

_{npm package: lark-agent-bridge · git repo: dsh-lark-bridge (repo name kept; clone paths below are unchanged)}

A Feishu / Lark bridge for local coding agents — one group, one conversation, one pinned runtime. Bridges dsh (in-process plugin), CLI agents (traex / codex, spawned by a daemon), an IDE window (attached over a socket), or a custom agent — behind one gateway.

中文 README

Send a message in a Feishu chat, and a real coding agent — with its own tools, its own project directory, and its own persistent conversation — answers you right there. Each group chat is an isolated workspace pinned to exactly one runtime, so a team can run several projects (and several agents) in parallel, one per group.

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What it does

• Feishu ⇄ your agent. Inbound Feishu messages drive a live agent; the reply streams back onto a live-updating Feishu message. The agent is whichever runtime this chat is pinned to (dsh / CLI / IDE / custom).
• Four host classes, one contract. Every runtime implements the same AgentAdapter: dsh runs in-process as a plugin; CLI spawns traex/codex; IDE attaches a running window; custom loads your own module. They never silently replace each other.
• One group, one conversation, one pinned runtime. Every chat id maps to a stable directory (<workspaceRoot>/<chatId>) and one runtime chosen with /agent. Different groups never touch each other's files, and a message is never broadcast to several agents. If the pinned runtime is down (e.g. an IDE window closed), that chat fails closed instead of retargeting.
• Persistent per-chat sessions. A chat's conversation survives restarts (policy-fingerprint-gated resume-or-create; /new really clears it).
• Files and images. Send them to the bot and the bridge stores each message in an isolated .attachments/<messageId>/ folder, then gives the paths to the agent. Limits: 5 attachments per message, images ≤10 MB, other files ≤20 MB; names are sanitized and stale files are swept after 7 days. Whether an image can actually be interpreted depends on the selected model's vision support.
• Zero-config setup. On first launch, if no credentials exist, a QR registration wizard runs — scan it in the Feishu app and it connects automatically. No portal spelunking.
• Slash commands. /help, /new, /where, /models, /agent, and /whoami manage each chat locally; owner-only /agent, /model, /preset, /allow, and /disallow change shared chat state. /agent pins this chat to one installed runtime and never silently retargets.

Architecture in one picture

①  Feishu Open Platform      ← register a bot here (auto QR wizard does it for you)
        │  gives: app_id + app_secret
        ▼
②  lark-agent-bridge gateway  ← holds the keys, opens a WebSocket to Feishu,
        │                        turns each message into one agent turn,
        │                        routes each chat to its pinned runtime
        ▼
③  the pinned runtime         ← one of:
     • dsh    — in-process Cordis plugin (`dsh web`)
     • CLI    — daemon spawns traex / codex
     • IDE    — daemon attaches a running window over a socket
     • custom — daemon loads your own AgentAdapter module

The bot registration lives entirely on Feishu. The gateway connects out to Feishu over a long-lived WebSocket (so no public IP or callback URL is needed). For dsh the gateway is the plugin loaded by dsh web; for CLI / IDE / custom it is a separate daemon (node lib/daemon.js), independent of any dsh host.

pnpm build
node lib/daemon.js                            # spawn traex/codex on PATH
LARK_BRIDGE_RUNTIME=traex node lib/daemon.js
LARK_BRIDGE_IDE_SOCKET=/tmp/ide.sock node lib/daemon.js
LARK_BRIDGE_CUSTOM_ADAPTER=./examples/custom-adapter.mjs node lib/daemon.js

CLI spawns the binary. IDE attaches a Unix-socket JSONL sidecar (window closed ⇒ that line dies). Custom loads an AgentAdapter module (see examples/custom-adapter.mjs). One group is still one conversation pinned with /agent; a dead line is not retargeted.

ByteDance-only overlay (SSO, bytecli, extra presets) lives in a local internal/ directory that is gitignored. Do not publish it to this GitHub repo; ship it through the internal skill marketplace.

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Requirements

• A working DeepSeek Harness (dsh) checkout you can launch with dsh web.
• Node.js ^22.19.0 || >=24.0.0.
• A DeepSeek API key (set DEEPSEEK_API_KEY, or configure it in your dsh credentials).
• A Feishu account to scan the QR code (the wizard creates the app for you).

Install

Build first. This repo ships TypeScript source; the compiled lib/ is git-ignored, so a fresh clone has NO build output. The plugin's entry is lib/index.js, so installing without building gives dsh an empty package and the host fails to load it. pnpm setup builds for you; if you install manually, run pnpm install && pnpm build first.

Option 1: one-command setup (recommended)

git clone https://github.com/bihangchi9-creator/dsh-lark-bridge.git
cd dsh-lark-bridge
pnpm setup            # macOS / Linux (scripts/setup.sh) — builds, links, registers
pnpm setup:win        # Windows (scripts/setup.ps1)

The script preflights your Node version, builds the plugin (fails loudly if the build fails), installs the access-tier presets, and registers both the bridge and its dsh-tool-lark-cli dependency. When dsh is available it uses the official dsh plugin command, which initializes a missing web or headless profile automatically — no preliminary dsh web launch is needed. After that, launch dsh directly with no --patch flag:

# macOS / Linux
DSH_PERMISSION_MODE=danger-full-access dsh web

# Windows PowerShell
$env:DSH_PERMISSION_MODE = "danger-full-access"; dsh web

Different profile: DSH_PROFILE=headless pnpm setup; custom dsh home: DSH_HOME=/path/.dsh pnpm setup (both env vars work on Windows too). If no dsh command is available, setup can only use its manual fallback and therefore requires an already-initialized profile; it fails before building or copying presets, so it leaves no partial installation.

Option 2: official dsh plugin command (build first!)

git clone https://github.com/bihangchi9-creator/dsh-lark-bridge.git
cd dsh-lark-bridge
pnpm install && pnpm build          # REQUIRED — link installs pull lib/ from this dir
# then, from your dsh checkout:
dsh plugin --profile web add link:/path/to/dsh-lark-bridge

dsh plugin runs pnpm add in the profile directory and auto-reconciles dsh.profile.bundles: a package that declares dsh.bundle joins the layer stack automatically. Remove/update with the same family: dsh plugin --profile web remove lark-agent-bridge / dsh plugin --profile web update lark-agent-bridge.

⚠️ A link: install points the profile dependency at THIS directory. If you later move or delete it, the next dsh web cannot resolve the bundle and fails to boot. Keep the clone in place, or use Option 1.

Option 3: manual install (source mode)

Because the dsh public npm graph is still partial, install from source alongside your dsh checkout.

# 1. Clone next to your dsh checkout; install & build
git clone https://github.com/bihangchi9-creator/dsh-lark-bridge.git
cd dsh-lark-bridge
pnpm install
pnpm build            # compiles src/ -> lib/  (REQUIRED before the plugin can load)

Then register it as a dsh bundle (once it's in the profile, dsh web loads it automatically — no --patch):

# 2. Link it into the profile's node_modules (bundle resolution anchor)
#    macOS / Linux:
mkdir -p ~/.dsh/profiles/web/node_modules
ln -s "$(pwd)" ~/.dsh/profiles/web/node_modules/dsh-lark-bridge
#    Windows PowerShell (directory junction — no admin rights needed):
#    New-Item -ItemType Junction -Path "$env:USERPROFILE\.dsh\profiles\web\node_modules\dsh-lark-bridge" -Target (Get-Location).Path

# 3. Append the package name to dsh.profile.bundles in ~/.dsh/profiles/web/package.json:
#    "bundles": ["@deepseek-ai/dsh-base", "@deepseek-ai/dsh-web-app", "lark-agent-bridge"]

Launch dsh (the bundle loads the plugin automatically):

# from your dsh checkout
DSH_PERMISSION_MODE=danger-full-access dsh web

DSH_PERMISSION_MODE=danger-full-access makes the agent's approval policy never. This is needed because Feishu users cannot click through a local approval prompt. Only use it in an environment you trust.

Platform notes (Windows vs macOS/Linux)

Item	macOS / Linux	Windows
One-command setup	pnpm setup (scripts/setup.sh)	pnpm setup:win (scripts/setup.ps1)
dsh home directory	~/.dsh (i.e. $HOME/.dsh)	%USERPROFILE%\.dsh
Directory link	ln -s (symlink)	New-Item -ItemType Junction (junction — no admin rights needed)
Env var syntax	DSH_PERMISSION_MODE=danger-full-access dsh web	PowerShell: $env:DSH_PERMISSION_MODE="danger-full-access"; dsh web; cmd: set DSH_PERMISSION_MODE=danger-full-access && dsh web
Registration URL file	~/.dsh-lark-bridge/register-url.txt	%USERPROFILE%\.dsh-lark-bridge\register-url.txt
Run as a background service	launchd (macOS) / systemd (Linux)	Task Scheduler (schtasks)
QR registration / build / chat commands	identical everywhere	identical everywhere

The two setup scripts behave identically and are idempotent: preflight → build → link → register bundle.

First run: register your bot

Every user registers their own Feishu bot — you cannot share an app_secret, as that hands over control of your bot.

On the first launch with no credentials, the plugin prints a QR code in the terminal (and writes the raw URL to ~/.dsh-lark-bridge/register-url.txt for backgrounded runs). Steps:

1. Open the Feishu mobile app, scan the QR code.
2. Confirm creating a self-built app on your phone.
3. The plugin receives the credentials, saves them to ~/.dsh-lark-bridge/credentials.json, and connects automatically.
4. Add the bot to a group (or DM it) and start talking.

Prefer to do it manually / re-register / switch accounts? Run the standalone wizard:

pnpm register           # or: npx dsh-lark-register

Already have credentials? Skip the wizard entirely by exporting them:

export LARK_APP_ID=cli_xxx
export LARK_APP_SECRET=yyy
export LARK_TENANT=feishu      # or `lark` for larksuite.com

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Using it in a chat

Command	What it does
(any text)	A prompt to this chat's agent
/help	Show help
/new	Start a fresh session (clears this chat's context)
/where	Show this chat's project directory
/models	List available providers/models
/model [provider/model]	(owner only) Show or switch the model for this chat
/preset [workspace|read-only|full]	(owner only) Show or switch this chat's access tier
/agent [id]	Show this chat's runtime; owner pins it (dsh today). A dead line is not retargeted
/whoami	Show identity, this chat's runtime, and authorization
/allow	(owner only, group chats) Authorize this chat to use the bot
/disallow	(owner only, group chats) Revoke this chat's authorization

In a group chat, @-mention the bot to trigger it (unless mention is disabled). In a DM, just send a message.

Configuration

Every field can come from the plugin config: block or an environment variable (env is the friendlier default).

Config	Env var	Default	Meaning
appId	LARK_APP_ID	—	Feishu app id (cli_...)
appSecret	LARK_APP_SECRET	—	Feishu app secret
tenant	LARK_TENANT	feishu	feishu (feishu.cn) or lark (larksuite.com)
provider	DSH_LARK_PROVIDER	dsh default	LLM provider route
model	DSH_LARK_MODEL	dsh default	Model for created agents
workspaceRoot	DSH_LARK_WORKSPACE_ROOT	~/dsh-lark-workspaces	Root for per-chat folders
allowDm	DSH_LARK_ALLOW_DM	true	Respond in direct messages
requireMention	DSH_LARK_REQUIRE_MENTION	true	In groups, require an @-mention
turnTimeoutMs	DSH_LARK_TURN_TIMEOUT_MS	600000	Hard deadline for one agent turn; timeout disposes the stuck session
allowedChats	DSH_LARK_ALLOWED_CHATS	[]	Chat ids allowed to use the bot (comma-separated). Empty = no group allowed (fail-closed)
allowedUsers	DSH_LARK_ALLOWED_USERS	[]	User open_ids allowed to DM the bot (comma-separated). Empty = only the owner may DM
accessMode	DSH_LARK_ACCESS_MODE	workspace	Default access tier: read-only, workspace, or full
extraPresets	DSH_LARK_EXTRA_PRESETS	{}	Extra id:preset-name pairs
ssoGatedPresets	DSH_LARK_SSO_GATED_PRESETS	[]	Preset ids that must pass host SSO on switch and on every turn
ssoCheckCmd	DSH_LARK_SSO_CHECK_CMD	—	SSO status command, parsed as argv without a shell
ssoOkMarker	DSH_LARK_SSO_OK_MARKER	Authenticated	Required text in successful SSO output
presetModels	DSH_LARK_PRESET_MODELS	{}	presetId:provider:model routes

Credentials are read in this order: inline config → environment variables → the file written by the registration wizard.

Access control (security model)

The bot's security boundary is exactly "who may send it a message": every message becomes an agent turn with host-level permissions, so access is deny-by-default:

• The owner always passes. The person who scanned the QR at registration is the owner (open_id stored in credentials.json); older installs are backfilled automatically at startup via the app-info API.
• Groups: only chat ids listed in DSH_LARK_ALLOWED_CHATS may use the bot.
• DMs: only open_ids listed in DSH_LARK_ALLOWED_USERS may use the bot (owner always allowed).
• Fail-closed: with an unknown owner and empty allowlists, every message is denied — the denial reply includes the chat id so you can configure it.

Example:

# Allow groups oc_xxx1, oc_xxx2 and let ou_friend DM the bot
export DSH_LARK_ALLOWED_CHATS="oc_xxx1,oc_xxx2"
export DSH_LARK_ALLOWED_USERS="ou_friend"

Runtime owner resolution needs the application-info scope; the registration wizard captures the open_id directly, so usually nothing extra is needed. Any deployment reachable by people outside your team should configure the allowlists.

Access tiers (blast radius)

Even after the access gate passes, what an agent may touch is tiered (DSH_LARK_ACCESS_MODE, default workspace):

Tier	Preset	What the agent can do
read-only	lark-readonly	search/read files only — no writes, no shell, no network
workspace (default)	lark-workspace	read/write/edit files; no shell, no network, no subagents (no arbitrary code execution). Ships with a lark_cli tool: Feishu operations (IM, docs, sheets, calendar, …) via the host's authenticated lark-cli, spawned as an argv array with a timeout and output cap — Feishu power without opening a shell
full	deployment default	everything the host offers (shell, network, subagents)

Presets are dsh's toolset compositions: the host sandbox is identical for every preset, so the enforceable difference between tiers is which tools exist. The workspace tier removes the crown jewels of the attack surface — arbitrary code execution, network egress, and delegation.

The setup scripts (pnpm setup / pnpm setup:win) install the presets into the harness-home user root automatically. Manual install (discovery is uncached):

mkdir -p ~/.dsh/.agent-presets
cp -r presets/lark-workspace presets/lark-readonly ~/.dsh/.agent-presets/

Further host-level hardening: dsh's workspace-write permission preset (sandbox = writes inside the workspace, wider operations require approval) hard-bounds fs writes — but for remote users "wider" means "denied" (nobody can click the approval prompt), and it changes shell behavior, so verify it in your target deployment before enabling. The plugin-level tiers already remove shell/web/subagents, which is the highest value-per-risk change.

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Pairs well with lark-cli

If you already use lark-cli / the Lark skills to drive Feishu (docs, sheets, IM, calendar…), this plugin slots in beside it: keep using lark-cli for structured Feishu operations, and let Lark Agent Bridge be the conversational coding agent living in your group chats. You're very welcome to combine the two — for example, ask the agent in a group to draft something, then use lark-cli skills to push it into a Feishu doc.

Troubleshooting

• Bot says nothing / "(no output)" — make sure a model is resolvable (dsh's default model service must be configured, or set DSH_LARK_MODEL).
• "missing Feishu credentials" — the wizard didn't complete; re-run pnpm register or export LARK_APP_ID / LARK_APP_SECRET.
• QR not visible (backgrounded dsh) — open the URL saved at ~/.dsh-lark-bridge/register-url.txt in a browser.
• Group messages ignored — you must @-mention the bot, or set DSH_LARK_REQUIRE_MENTION=false.

Credits

Lark Agent Bridge (npm lark-agent-bridge, repo dsh-lark-bridge) is a creative extension of lark-coding-agent-bridge (originally feishu-claude-code-bridge) by zarazhangrui, by way of trae-to-lark. This project is a native DeepSeek Harness plugin reimplementation. All original work remains under its MIT license; see LICENSE and NOTICE for the full copyright chain.

License

MIT