dsh-network-config

dsh-network-config

Proxy settings for DeepSeek Harness — a Network page in Settings where you pick how the whole app reaches the internet, and it takes effect immediately.

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Settings → Network
  ( ) Follow system     read the Windows system proxy and follow its on/off switch
  ( ) Direct            no proxy at all
  (•) Custom            point at your own http(s) proxy, with a bypass list

No restart, no environment variables to export, no editing YAML. Models, web search, web fetch, and HTTP MCP all move to the new route the moment you hit Save.

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Why it exists

DeepSeek Harness reads its outbound proxy policy once, at launch, from the http_proxy / https_proxy / no_proxy / all_proxy environment variables. That leaves two everyday problems:

1. You have to set environment variables before starting the app, and restart it every time your proxy changes.
2. "Follow the system proxy" isn't supported at all — the harness deliberately refuses to read the OS proxy configuration, so a user who flipped the switch in their proxy client still has to export variables (documented limitation).

This plugin adds the missing surface, and while doing so it also fixes a bug that silently breaks LAN access — see below.

Built-in bypasses (the part that matters)

Whenever a proxy is in use, these destinations always stay direct, with no configuration from you:

Category	Ranges
Loopback	localhost, 127.0.0.0/8, ::1
Private (RFC 1918)	10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16
Link-local	169.254.0.0/16, fe80::/10
Carrier-grade NAT	100.64.0.0/10 (also where Tailscale lives)

A forward proxy resolves addresses in its own network, so handing it an intranet destination only ever produces a timeout or a 502. That is exactly what happens with the harness alone: it exempts loopback and nothing else.

And every entry the operating system wrote into its bypass list is honoured — including the forms the harness's own matcher cannot express:

Entry Windows writes	Meaning	Harness alone	This plugin
192.168.*	prefix wildcard	❌ never matches	✅
10.0.0.0/8	CIDR	❌ never matches	✅
``	any host without a dot	❌ never matches	✅
*.corp.example	suffix	✅	✅
api.test:8443	host with port	✅	✅

Measured on a real machine with a system proxy configured (a local model endpoint on a private address, reachable directly in ~20 ms). The addresses and ports below are stand-ins from the documentation ranges:

Target	Harness alone	With this plugin
http://100.64.0.10:8080/v1/models (CGNAT range)	HTTP 502 · 5175 ms	HTTP 401 · 22 ms
http://172.20.0.10:8080/v1/models (private range)	401 · 8 ms	401 · 4 ms
https://www.deepseek.com/	200	200 · 253 ms (still proxied — correct)

Install

Requirements: DeepSeek Harness desktop (Windows for the Follow system mode; elsewhere the plugin still works, but that mode falls back to reading the environment) and PowerShell.

1. Download dsh-network-config-1.0.0.zip from the releases page — or clone this repo.
2. Extract anywhere, then in that folder:

powershell -ExecutionPolicy Bypass -File .\install.ps1

3. Fully quit and reopen DeepSeek Harness. The module graph is built at startup; a running app cannot pick up a newly installed plugin.

4. Verify:

powershell -ExecutionPolicy Bypass -File .\verify.ps1

1. Is the plugin mounted at http://127.0.0.1:19387 ?   YES
2. mode: system   route: http://127.0.0.1:7890/
   bypass entries: 21   private direct: True   full matcher: True
3. Reach a public address (must use the proxy) : https://www.deepseek.com/
   reachable - HTTP 200 in 163 ms

Full walkthrough, manual install, migration to another machine, and a troubleshooting list: INSTALL.md.

Uninstall

powershell -ExecutionPolicy Bypass -File .\install.ps1 -Uninstall

Then restart the app. The plugin occupies one directory plus one line in the profile's dsh.profile.bundles; its only data file is %USERPROFILE%\.dsh\network-config.json.

How it works

The plugin never builds its own proxy policy from scratch. It hands the resolved mode to @deepseek-ai/dsh-http-proxy — the harness's own package — so proxyRouteFor(), the published environment variables, and every spawned child process all keep seeing one consistent answer.

It then swaps the dispatcher that actually carries the traffic for its own per-origin agent, because that package's bypass matcher only does exact-host and suffix matching. Both halves are needed: the package keeps the process-wide contract, the plugin's matcher implements the entries that contract cannot express.

Settings → Network          (client/client.js)
     │  GET  /dsh-network-config/state
     │  POST /dsh-network-config/state   { mode, custom: { proxy, bypass } }
     ▼
host half                   (lib/index.js)
     │  validate → store.save → resolvePolicy
     ├─ installProxyFromEnvironment   ← the official policy: proxyRouteFor(),
     │                                  env vars, child processes
     └─ installRouting(compileBypass) ← the dispatcher that carries traffic
     ▼
undici global dispatcher + http_proxy / https_proxy / no_proxy

Source map

File	Role
lib/index.js	Host half: settings document, policy resolution, transport install, the HTTP routes
lib/bypass.js	The bypass matcher: wildcards, CIDR, ``, suffixes, ports, private-address detection
lib/routing.js	Per-origin undici dispatcher that asks lib/bypass.js where each request goes
lib/system-proxy.js	Windows system proxy discovery (reg query → proxy URLs + bypass list)
lib/policy.js	The three modes → a transport policy
lib/store.js	Validation and atomic read/write of network-config.json
lib/text.js	Host-side diagnostic copy
client/client.js	Browser half: one packaged window.__ModuleLoader__ module registering the page into settings.section
install.ps1 / verify.ps1	Installer and post-restart verifier
build-package.ps1	Builds the portable zip
test/	39 unit tests

The plugin's HTTP routes are fenced like the harness's own plugin routes: the Host header must be loopback and a browser-marked cross-site request is refused. That is a DNS-rebinding defense, not authentication.

Known limitations

• No SOCKS and no PAC. The transport accepts http(s):// proxy URLs only. A system configured with a PAC script (AutoConfigURL) is reported and treated as direct rather than pretending to work.
• proxyRouteFor() uses the package's narrower matcher. Because the official policy is installed as-is, dsh-web-fetch-http decides whether to fetch through the proxy with that matcher — so fetching an intranet URL can still be routed through the proxy. Public fetches are unaffected. Traffic (models, search, MCP) goes through this plugin's matcher.
• Child processes follow the policy only on Node 22.21+/24+. That is dsh-http-proxy's documented behaviour, driven by NODE_USE_ENV_PROXY. In Direct mode the plugin additionally clears all_proxy/ALL_PROXY so children do not keep using one.
• Needs undici resolvable from inside the profile. Without it the plugin falls back to the package's dispatcher and says so in the page — usable, but wildcard entries and private-address bypass stop applying.
• Exclusive with other proxy plugins. Whoever calls setGlobalDispatcher last wins; do not run this alongside e.g. dsh-clash-proxy.
• System proxy discovery is Windows-only; other platforms fall back to the environment.

Development

npm test          # or: node --test test/*.test.mjs

No build step, no dependencies. The browser half is a hand-written window.__ModuleLoader__ bundle and the tests load it exactly the way the client does, then assert on the page's element tree — so no DOM or React renderer is needed.

Contributions are welcome — see CONTRIBUTING.md.

License

MIT — see LICENSE.

Not affiliated with DeepSeek. "DeepSeek Harness" refers to the upstream application this plugin extends.