DeepSeek++: a Chrome, Edge and Firefox extension that turns the DeepSeek web chat into an agent workspace

What DeepSeek++ adds to chat.deepseek.com

The DeepSeek web app is a chat box. It answers, it remembers nothing between conversations unless you paste context back in, and it cannot touch a file, a browser tab or an external service. DeepSeek++ is a browser extension for Chrome, Edge and Firefox that keeps the DeepSeek page as the interface and adds the machinery around it: MCP tool management, long-term memory, project context, Skills, automation tasks, web search, page reading, multimodal media analysis and conversation export. The README describes it as an AI agent workspace rather than a chat wrapper, and the distinction is real: the extension intercepts tool-call requests in the model output, executes them, and feeds the results back into the same conversation.

The audience is narrow and specific. You already use chat.deepseek.com in a browser, you want tool execution and persistent memory without moving to a desktop client or wiring up your own API integration, and you are willing to install a third-party extension that reads the page you are chatting on. The README states the extension is local-first: memory, presets, custom Skills, automation prompts and MCP configuration are stored by the user, and the project does not run a backend that collects exported conversations. That claim is about architecture, not an audit, and the repository does not include a security review.

How tool calls, memory and the native host fit together

The extension is built with WXT and TypeScript, with a workspace layout under packages/ and entrypoints/ for the extension surfaces. The mechanism that matters is the tool-call loop. The model emits a tool-call request in its output; the extension recognises it, executes it, hides the raw call from the page, and renders the result as a collapsible block that looks like the built-in "thinking" section, for example "called tools (2 times)". Multiple calls can run in one reply, and the execution record survives a page refresh. There is no manual copy step and no confirmation prompt per call, which is the design choice that makes it feel native and also the one that deserves scrutiny.

Two execution paths exist. Pure browser work (web search, page reading, conversation export, saved snippets) runs in the extension. Anything that needs the local machine goes through a native messaging host, which is a separate install. The README is explicit about what changes with it: image and video attachment in the DeepSeek input box requires the multimodal Native Host, and MCP servers are managed from the sidebar with tool permissions and execution status. The native host is also where the file-reading reliability work lives. For local_file_read, the README says the extension side loops deterministically over files larger than a single read limit instead of trusting the model to continue, advances the read position by Unicode code point rather than UTF-16 unit so emoji and Chinese text survive window boundaries, and reads byte windows on demand in the host so a very large file is not loaded into memory whole. That is a concrete failure mode addressed with a concrete fix, and it is the most technically specific part of the documentation.

Installing DeepSeek++ and running a first tool call

The README points to the Chrome Web Store listing for the packaged extension, and the package.json shows the build path for the other browsers. If you want the Edge or Firefox build, or you want to run from source, the project uses WXT. The scripts below come from package.json and require Node and npm; the repository ships a package-lock.json and declares npm workspaces under packages/*.

Installing DeepSeek++ and running a first tool call (continued)

Once the extension is loaded, sign in to chat.deepseek.com in that browser profile. The sidebar exposes the conversation page, memory, projects, Skills, MCP and automation. Memory is the fastest thing to verify, because it needs no extra install: ask a question, then check that a preference you state is stored and injected into a later conversation. Skills are addressable with the /skill command, and the README says they can be built in, written by you, or imported from GitHub. Automation tasks are placed in their own DeepSeek conversation and can run immediately, on a schedule, or be stopped manually.

MCP is the part that needs the native host. The sidebar manages MCP services, tool permissions and execution status, and results return to the same conversation. The README does not document the native host installation steps in the excerpt available, so treat the host installer as something to locate in the repository before you plan around MCP. The same applies to the multimodal host for image and video attachment in the input box; without it, image attachment is limited to the sidebar's image-recognition mode.

Where DeepSeek++ is the wrong tool

The extension depends on the DeepSeek web page. It is not an API client and it does not replace one. If DeepSeek changes its DOM or its streaming format, the extension's interception layer is the thing that breaks, and the README does not describe a compatibility contract or a fallback mode. You are building a workflow on top of a page you do not control.

The native host is a second boundary. MCP tool execution, local file reading and multimodal attachment all route through it, so the extension is only as capable as that install. The README does not document rollback, per-tool sandboxing, or how to revoke a tool permission after the fact beyond the sidebar's permission controls. Browser control is scoped to a tab you select and enable, and the README states the floating chat entry does not read or send the current page body on its own; but the extension does hold page access on the sites where you enable it, and that is a trust decision no feature list settles.

Language handling has a documented edge. Switching between Simplified Chinese and English changes the sidebar, context menus, tool results, built-in tool descriptions and auto-continue prompts, but the README says user-written memory, presets, custom Skills, automation prompts, MCP configuration and synced data are preserved as written and not translated. That is the right call, and it also means a mixed-language workspace is the expected state, not a bug.

DeepSeek++ compared with a plain MCP client

A general MCP client such as Claude Desktop or a chat client with MCP support takes a different route: the model, the tool registry and the host all live in one application the vendor ships, and the tool loop is part of that application rather than an interception layer over a web page. You get a supported integration path and you give up the DeepSeek web interface, its login-based usage, and the memory and project features the extension stores locally.

DeepSeek++ inverts the trade. You keep the DeepSeek web chat you already use and the extension adds the agent layer around it, including memory, Skills, projects, saved snippets, conversation export to HTML, Markdown or PDF, and scheduled automation. The cost is that the agent loop is only as stable as the page it wraps, and the native host is yours to install and maintain. If your work is already anchored to chat.deepseek.com, that cost buys a lot. If you need a tool-execution stack you can pin to a version and support contractually, a standalone MCP client is the safer base.

Maintenance, licence and what to check before adopting

The repository is not archived, and the last push was on 2026-08-13. Releases are frequent: v1.14.0 on 2026-08-08, v1.13.1 on 2026-08-06 and v1.13.0 on 2026-08-05. That cadence is the practical upgrade cost. The extension is distributed through the Chrome Web Store, so packaged users get updates on the store's schedule, while source builds need a rebuild and a reload for each release. The package.json carries verify scripts for manifest policy, extension UTF-8, sidepanel chunk budget, release assets and bundled skill packaging, which suggests the project treats those checks as part of shipping; it also means a source build is expected to be run through them.

The licence is Apache-2.0, declared both in the repository and in package.json. That permits commercial and private use, modification and redistribution, with the usual conditions around notices and patent termination. It does not grant any rights to the DeepSeek service itself, and the extension's behaviour remains bound by DeepSeek's own terms. Nothing here is legal advice; if you plan to redistribute a modified build, read the LICENSE file in the repository.

Editorial conclusion

Adopt DeepSeek++ if your work already happens inside chat.deepseek.com and you want tool calls, memory, Skills and scheduled tasks inside that same tab, without a separate desktop client or API key. Skip it if you need a vendor-supported product, a documented security review, or agent behaviour on sites other than DeepSeek with a hard guarantee of what the extension can read. Verify first: which Chrome, Edge or Firefox build you need, whether your MCP server speaks the stdio transport the native host expects, and whether the export formats you need are HTML, Markdown or PDF.

Frequently asked questions

Official sources

1. License: Apache-2.0
2. Project website
3. README
4. Releases
5. zhu1090093659/deepseek-pp on GitHub