🛰️ dsh-lsp-actions

The LSP action surface for DeepSeek Harness — real language servers, real feedback, and the IDE integration backend for editors.

Diagnostics, formatting, completion, code actions, symbols, signature help, inlay hints, and rename for your agent's editor loop — plus the stable editor action protocol (lsp.actions.*) that lets any editor consume them directly.

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Compatibility

Surface	Status
Harness	DeepSeek Harness `0.1.0-rc.6` (compat declared for `>=0.1.0-rc.6`)
Node	`^22.19.0 \|\| >=24.0.0`
Platforms	All (pure host; subprocess + filesystem, no network)
Model	Any (tools are model-agnostic; the plugin never calls a model)

What you get

dsh-lsp-actions mounts as a single host row (id: lsp-actions, name: dsh-lsp-actions, inject: [tools, fs, subprocess]). The official DeepSeek Harness ctx.lsp seam covers navigation (go-to-definition, references, implementation, hover); this plugin completes the action surface — the feedback loop an agent needs while it writes and fixes code:

Eight lsp_* tools — diagnostics, formatting, completion, code actions, symbols, signature help, inlay hints, and rename, all served by the same language servers your IDE uses.
Editor action protocol v1 — a stable JSON-RPC surface (lsp.actions.list / lsp.actions.run / lsp.events) that lets any editor (VS Code first) consume those capabilities directly.
Real-server verification — a real typescript-language-server run is part of the test suite (self-contained, CI on Node 22/24 across Linux, Windows, and macOS), not just mocks.

Quick start

# 1. install the bundle into your profile
dsh plugin --profile web add "github:PerryLink/dsh-lsp-actions#main"

# or from npm (published releases)
dsh plugin --profile web add dsh-lsp-actions

# 2. restart and verify the row
dsh --profile web --dump-config | grep -A3 'id: lsp-actions'

Install & uninstall

git channel (latest main): dsh plugin --profile web add "github:PerryLink/dsh-lsp-actions#main" — the prepare script builds (tsc --noEmitOnError).
npm channel (published releases): dsh plugin --profile web add dsh-lsp-actions.
tarball channel: pnpm pack in this repo, then dsh plugin --profile web add ./dsh-lsp-actions-<version>.tgz.
uninstall: dsh plugin --profile web remove dsh-lsp-actions (or remove the row from the profile patch).

Configuration

All tunables are Schemastery Config fields (changeable from cordis.yml). An id-targeted override replaces the whole row — restate every key you need. cordis.patch.yml documents each key inline.

Key	Default	Meaning
`servers`	`{}`	Named language servers; an empty table activates no servers
`editor.enabled`	`false`	Serve the editor action protocol over JSON-RPC stdio (headless backend only)
`editor.requestTimeoutMs`	`60000`	Per-run timeout budget (ms) for the editor protocol
`editor.diagnosticsCacheMaxFiles`	`64`	Bounded LRU diagnostics-cache size (files)
`maxDiagnostics`	`200`	Diagnostics cap per result
`maxCompletionItems`	`20`	Completion-items cap per result
`maxCodeActions`	`50`	Code-actions cap per result
`maxSymbols`	`100`	Symbol-results cap
`maxSignatures`	`10`	Signature-help cap
`maxInlayHints`	`200`	Inlay-hints cap
`maxResultChars`	`16000`	Rendered-result cap (chars)
`maxDocumentBytes`	`4000000`	Document-read cap (bytes)
`timeoutMs`	`60000`	Per-call timeout, enforced by the official timeout policy

Each servers entry is an LspServerEntry: command (executable resolved on PATH at load) and extensionToLanguage (".ts" → typescript) are required; optional fileGlobs, args, env, initializationOptions, configuration, formattingOptions, maxMessageBytes, maxStderrBytes, killGraceMs, shutdownTimeoutMs, diagnosticsSettleMs, diagnosticsDebounceMs, and idleTimeoutMs (0 = keep the server process alive) tune the built-in stdio client.

Tools & surfaces

Surface	Kind	Notes
`lsp_diagnostics`	tool	`<file>` — compiler/analyzer errors, warnings, and hints with severity, range, message, and source server (read-only)
`lsp_format`	tool	`<file> [range?]` — formats a file/selection through the language server and applies it, returning the diff (writes via `fs/write-intent`)
`lsp_completion`	tool	`<file> <line> <character>` — completion suggestions at a cursor position, including the insertion text (read-only)
`lsp_code_action`	tool	`<file> [range?] [only?]` — server-verified quickfixes/refactorings with their edits, for a range or the first diagnostic (reference-only)
`lsp_symbols`	tool	`<query?> <file_path?>` — workspace-wide symbol search by name, or one file's outline (read-only)
`lsp_signature`	tool	`<file> <line> <character>` — signature help (parameters and documentation) inside a call (read-only)
`lsp_inlay_hints`	tool	`<file> [range?]` — type annotations and parameter-name hints from the server (read-only)
`lsp_rename`	tool	`<file> <line> <character> <new_name>` — server-verified rename, applied workspace-wide with per-file diffs (writes via `fs/write-intent`)
`lsp.actions.*`	protocol	Editor action protocol v1: `lsp.actions.list` / `lsp.actions.run` / `lsp.events` over JSON-RPC
`examples/vscode/`	extension	UI-only VS Code extension plus the headless backend composition it connects to

Editor action protocol v1

When editor.enabled: true is set in a dedicated headless composition, dsh-lsp-actions serves a stable editor protocol over newline-delimited JSON-RPC 2.0 (the same wire framing as the official SDK/ACP transports):

Method	What it does
`lsp.actions.list`	Returns the `lsp-actions/v1` protocol version, the action catalog (`diagnostics.get`, `completion.get`, `quickfix.apply`, `format` — each flagged `writes`), and the addressable DSH sessions
`lsp.actions.run`	Executes one action with a structured `{ requestId, action, status, result \| error }` envelope; errors carry the stable `LSP_ACTION_*` codes
`lsp.events`	Subscribes to the streamed `lsp.event` notifications: `diagnostics.updated`, `action.status`, `file.changed`, `sessions.changed`

All write actions (quickfix.apply, format) go through the official permission presets and approval: a read-only session is refused with LSP_ACTION_READ_ONLY before any server round-trip, edits ride the fs/write-intent waterfall, and the sandbox_permissions + justification escalation pair resolves through the official approveEscalation ask (fail-closed when no answerer can decide). Full wire spec, bilingual: docs/editor-protocol.md · docs/editor-protocol.zh-CN.md.

Versioning and the backward-compatibility promise

The protocol is versioned — lsp.actions.list returns protocol: "lsp-actions/v1", version: 1. v1 is frozen: field names, action ids, event kinds, and error codes stay stable forever.
Evolution is additive only: new actions, fields, and event kinds arrive without a version bump; existing semantics never change in place; a breaking change ships under a new protocol version, which servers may serve side by side.
Clients must ignore unknown fields, unknown event kinds, and unknown actions, and route on the stable error code, never on message text.

Error codes

Every failure carries a stable code; models and callers route on the code, never on message text.

Code	Meaning
`LSP_ACTION_UNAVAILABLE`	No server entry and no seam provider handles this file
`LSP_ACTION_UNSUPPORTED`	The server (or seam provider) does not advertise the operation
`LSP_ACTION_SERVER_FAILED`	The server failed (with its stderr tail); startup failures retry once
`LSP_ACTION_MALFORMED_RESPONSE`	The server sent a structurally invalid payload
`LSP_ACTION_CONFLICT`	The file changed since it was read, or the edits overlap / go out of bounds / leave the workspace
`LSP_ACTION_READ_ONLY`	The session's sandbox mode forbids the formatting/rename write
`LSP_ACTION_WORKSPACE_REQUIRED`	The calling session has no workspace cwd to root the server in
`LSP_ACTION_NO_SYMBOL`	The server found no renameable symbol at the cursor position
`LSP_ACTION_UNKNOWN`	Editor protocol: unknown action id, or no code action matched `title`/`index`
`LSP_ACTION_INVALID_ARGS`	Editor protocol: malformed action parameters
`LSP_ACTION_APPROVAL_UNAVAILABLE`	Editor protocol: the approval path could not grant a wider sandbox mode (fail-closed)
`LSP_PROTOCOL_VERSION_UNSUPPORTED`	Editor protocol: the declared protocol version is not supported

VS Code extension

examples/vscode/ ships a UI-only extension (sidebar with the DSH sessions, the diagnostics list, one-click quickfix apply, open-at-range, and format) plus the headless backend composition (backend/cordis.yml) it connects to over ACP-style JSON-RPC. The extension implements zero LSP logic — every capability and every byte written belongs to the plugin. Install steps, settings, and the demo-gif recording script are in examples/vscode/README.md.

Permissions & data

Permissions: formatting and rename ride the official permission presets and approval — the fs/write-intent waterfall and the sandbox_permissions / justification escalation pair resolved through ctx.approval. The plugin declares fs:read, fs:write, subprocess:spawn, and network:none in its workshop manifest.
Data: nothing is stored on disk; tool results live only in the session log (no cross-session persistence). The editor protocol keeps one bounded in-memory LRU diagnostics cache, freshness-stamped and never persisted across restarts.
No network: the plugin makes no network requests; it talks to language servers over local subprocess stdio.

Security boundaries

Read-only by default. Six of the eight tools are reference-only; only lsp_format and lsp_rename mutate, and they do so as real write/edit mutations.
Official seams, not re-implemented. Every byte goes through the fs/write-intent waterfall (observation → guarded write → observation) and the per-call sandbox policy; escalation matches the official write/edit tools.
Fail loud, fast, structured. Empty servers + no ctx.lsp seam → LSP_ACTION_UNAVAILABLE; read-only sessions → LSP_ACTION_READ_ONLY before any server round-trip; command forms are reported and never executed.
Conflicts never clobber. A file changed on disk after it was read fails with LSP_ACTION_CONFLICT; lsp_rename pre-flights every edited file before the first write.
Bounded work. Result caps, byte caps, and the platform's timeout policy bound every call; the diagnostics cache is a bounded LRU.
Nothing cached on the model path. Tool results live only in the session log; the diagnostics cache never persists across restarts.
Bad servers fail loudly. A missing executable fails at load; a server that dies at startup fails the call with LSP_ACTION_SERVER_FAILED plus its stderr tail (after one fresh-spawn retry).
Prompt hygiene. The plugin injects no persona or prompt prose into the session system prompt — its model-facing surface is the eight tool schemas.

Architecture

Actions run official-seam-first and fall back to the plugin's own minimal stdio client:

lsp_diagnostics / lsp_format / lsp_completion / lsp_code_action /
lsp_symbols / lsp_signature / lsp_inlay_hints / lsp_rename
        │
        ▼
   ctx.lsp seam (extended: diagnostics / formatDocument / completion)
        │  absent · legacy · no provider for this file
        ▼
   built-in stdio client  ←  servers table (ctx.subprocess.spawn + JSON-RPC)

The seam extension is proposed upstream (upstream/lsp-action-seam.patch, PR description in upstream/PR-description.md). Once it lands, the plugin keeps working unchanged — the built-in client simply stops being used. The built-in client stays as the standalone fallback for the servers table. The editor protocol rides the same runner, the same write path, and the same permission machinery. Full research and design notes: docs/seam-extension-notes.md.

Known limitations

Transient documents. Every action opens the file, runs one request, and closes it again (matching the official stdio host). Project-based servers that require a resident open file for document-free requests (tsls refuses workspace/symbol without one) are served by passing file_path to lsp_symbols. tsls also answers textDocument/signatureHelp with null under this lifecycle; other servers (gopls, pyright, rust-analyzer) serve it normally.
Range formatting requires the server's range provider. Servers that only advertise whole-document formatting fail range requests with LSP_ACTION_UNSUPPORTED.
Rename applies text edits only. Resource operations (create/delete/rename files) in a server's rename answer are refused with LSP_ACTION_UNSUPPORTED, and edits outside the workspace fail as LSP_ACTION_CONFLICT before anything is written.

Development

pnpm install            # node ^22.19 || >=24
pnpm run lint           # oxlint over src/ and tests/
pnpm test               # vitest: unit + fixture-server integration + editor-protocol e2e + real tsls e2e
pnpm run test:coverage  # coverage gate
pnpm build              # tsc --noEmitOnError → lib/
pnpm run prepare        # tsc --noEmitOnError (runs on install)
pnpm run prepublishOnly # tsc --noEmitOnError (runs before publish)

Topics

dsh, dsh-plugin, deepseek-harness, lsp, language-server, diagnostics, formatting, completion, code-action, symbols, signature-help, inlay-hints, rename, refactor, ide, editor, vscode, acp, json-rpc

Contributors

@PerryLink — creator and maintainer: the LSP action client and server lifecycle, all eight tools, the editor action protocol, tests, CI, and the five-language docs.

PerryLink DSH Plugin Family

This project is one of the 15 DeepSeek Harness plugins maintained by PerryLink. If this one helps you, the others likely will too:

Plugin	One-liner
dsh-mcp-panel	Read-only MCP runtime panel: /mcp command + Settings tab with status, tools and errors
dsh-doublecheck	Engineering-discipline guard: requirements grill, test gates, adversary review
dsh-background-agents	Durable background child agents with a Web UI sidebar, messaging and interrupt
dsh-lsp-actions	LSP diagnostics, formatting, completion, code actions and rename over language servers
dsh-output-styles	Claude Code outputStyles-equivalent runtime style switching
dsh-checkpoint-rewind	Claude Code /rewind-equivalent: snapshots, session forks, one-shot restore
dsh-permission-rules	Claude Code-style declarative allow/deny/ask permission rules with audit
dsh-auto-review	Second-model auto-review on the approval chain, fail-closed by default
dsh-memento	Approval-gated cross-session memory: ctx.memory seam + SQLite + memory tool
dsh-skill-pack-security	Security-audit skill pack: secret scan, dependency and supply-chain review
dsh-session-pin	Pin sessions in the Web sidebar with durable ordering
dsh-composer-history	Terminal-style input history for the web composer: arrows, Ctrl+R search
dsh-github	GitHub PR/issues integration for DSH, every write gated by approval
dsh-plugin-guide	Plugin-development knowledge base as an on-demand agent skill
dsh-claude-move	Migrate Claude Code sessions, memory, skills and CLAUDE.md into DSH

Name		Name	Last commit message	Last commit date
Latest commit History 24 Commits
.github		.github
docs		docs
examples/vscode		examples/vscode
src		src
tests		tests
upstream		upstream
verify		verify
.gitattributes		.gitattributes
.gitignore		.gitignore
CHANGELOG.md		CHANGELOG.md
LICENSE		LICENSE
README.es.md		README.es.md
README.hi.md		README.hi.md
README.md		README.md
README.pt.md		README.pt.md
README.zh.md		README.zh.md
SECURITY.md		SECURITY.md
cordis.patch.yml		cordis.patch.yml
package.json		package.json
pnpm-lock.yaml		pnpm-lock.yaml
pnpm-workspace.yaml		pnpm-workspace.yaml
tsconfig.json		tsconfig.json
vitest.config.ts		vitest.config.ts

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🛰️ dsh-lsp-actions

Compatibility

What you get

Quick start

Install & uninstall

Configuration

Tools & surfaces

Editor action protocol v1

VS Code extension

Permissions & data

Security boundaries

Architecture

Known limitations

Development

Topics

Contributors

PerryLink DSH Plugin Family

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🛰️ dsh-lsp-actions

Compatibility

What you get

Quick start

Install & uninstall

Configuration

Tools & surfaces

Editor action protocol v1

VS Code extension

Permissions & data

Security boundaries

Architecture

Known limitations

Development

Topics

Contributors

PerryLink DSH Plugin Family

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About

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