1 Why this is not “another Cursor article”
Standalone AI-native editors ship their own update channels, bundled runtimes, and vendor-chosen inference routes. VS Code plus extensions is messier in a useful way: the editor binary still talks to Microsoft infrastructure for updates and for the default gallery, while each extension author chooses CDNs, npm dependencies, and remote APIs. Cline and Roo Code sit in that second layer. They feel like “the AI feature,” yet under the hood they are ordinary extension hosts that open long-lived HTTPS sessions to whatever model provider you configured, often alongside OAuth or API-key flows that touch yet more domains.
If you only optimize “the AI domain” and forget marketplace.visualstudio.com or the blob host that serves .vsix payloads, you will still see slow installs, half-updated language servers, and mysterious offline banners inside an otherwise working browser. Conversely, if you tunnel the marketplace but leave extension subprocesses on a broken resolver path, the UI loads while completions never stream. A coherent Clash profile treats both layers as first-class citizens. That distinction is why this article complements—not duplicates—coverage of GitHub Copilot sign-in and model traffic in our Copilot routing guide and the Cursor IDE proxy article: those pieces assume different executables and default endpoints.
Throughout, remember that network policy must follow your local law and workplace rules. The following domain lists are observability-driven patterns for home labs and professional developers who already operate split tunnels responsibly, not encouragement to bypass restrictions.
2 Where Visual Studio Code spends HTTPS before Cline runs
Start with the editor shell. Search, metadata, and acquisition traffic for the default gallery typically hits marketplace.visualstudio.com and related Microsoft API hosts. Actual VSIX binaries are usually served from high-throughput CDNs—commonly hosts under vscode-unpkg.net, vscode-cdn.net, Azure blob patterns, or vo.msecnd.net style edge domains that change over time. In-flight updates and download redirects may touch update.code.visualstudio.com, vscode.download.prss.microsoft.com, or similarly named endpoints on the Microsoft edge network.
Telemetry and experiments add parallel names—think mobile.events.data.microsoft.com and cousins—which you may route direct on a locked-down machine or include in the same policy group as other Microsoft SaaS, depending on compliance. The actionable lesson is not to memorize every hostname forever; it is to watch your Mihomo or Clash Verge log while you perform a repeatable action such as “install one popular theme” or “check for updates,” then promote every new hostname you trust into a rule provider file you version in Git.
Corporate proxies and SSL inspection can break any of the above independently of Cline settings. If certificate validation fails only inside VS Code, fix trust stores before you disable TLS checks. Clash MITM features are unrelated; keep decryption off unless you fully own the pipeline.
3 Cline, Roo Code, and bring-your-own-key model traffic
Both Cline and Roo Code belong to the “agentic assistant” wave: they orchestrate edits, terminal commands, and tool calls through an LLM you supply. Because keys live on your machine, the extension’s outbound graph mirrors your provider choices, not a single vendor map. A minimal mental model includes: OpenAI-compatible hosts such as api.openai.com or regional gateways; Anthropic messaging endpoints under api.anthropic.com; Google Generative Language endpoints when you wire Gemini; and whichever Azure OpenAI, Vertex, or self-hosted OpenAI-compatible URL you pasted into settings.
Provider diversity is the reason generic “AI” GEOIP buckets fail here. Many inference APIs terminate on anycast fronts that do not match intuitive country tags. Prefer explicit DOMAIN-SUFFIX entries for providers you actually use, then attach them to a stable outbound group. If you hop between vendors weekly, maintain a small YAML snippet per provider and merge it with a mixin profile rather than editing a monolithic file by hand every time.
Some workflows add second-hop services: image models, web search plugins, or MCP servers that call npm registries and Git hosts. If you already standardized developer tooling proxies, align extension-spawned shells with the same environment variables so subprocesses do not leak around Clash. The MCP and package-registry split article is a useful cross-reference when tool calls leave the editor entirely.
4 DOMAIN-SUFFIX lists, rule providers, and a starter YAML fragment
Modern Mihomo-compatible cores excel at rule providers: downloadable or local files that expand into hundreds of lines you do not want to paste inline. For VS Code infrastructure, a pragmatic split is (a) a “microsoft-vscode-marketplace” list containing gallery and CDN suffixes, (b) a “model-providers” list for the APIs you personally enable in Roo Code or Cline, and (c) your usual catch-all GEOIP or MATCH behavior. Keep marketplace rules above broad DIRECT rules for domestic CDNs if you rely on split routing for latency-sensitive blobs.
The following fragment is illustrative—adjust policy group names (PROXY, DIRECT) to your profile, and replace the rule-providers URLs with files you trust or host yourself:
rule-providers:
vscode-marketplace:
type: http
behavior: domain
url: "https://example.com/rules/vscode-marketplace.txt"
path: ./providers/vscode-marketplace.yaml
interval: 86400
rules:
- RULE-SET,vscode-marketplace,PROXY
- DOMAIN-SUFFIX,marketplace.visualstudio.com,PROXY
- DOMAIN-SUFFIX,vscode-unpkg.net,PROXY
- DOMAIN-SUFFIX,vscode-cdn.net,PROXY
- DOMAIN-SUFFIX,open-vsx.org,PROXY
- DOMAIN-SUFFIX,api.openai.com,PROXY
- DOMAIN-SUFFIX,api.anthropic.com,PROXY
- DOMAIN-SUFFIX,generativelanguage.googleapis.com,PROXY
- MATCH,PROXYNotice the repetition: a RULE-SET plus a few high-signal DOMAIN-SUFFIX lines guard against a stale remote file missing a critical CDN rename. After any core upgrade, re-run your marketplace install test; CDNs evolve faster than blog posts.
DOMAIN-SUFFIX,microsoft.com style shortcuts can drag unrelated SaaS through an exit you did not intend. Prefer the smallest suffix that fixes the observed hostname from logs, then widen only when necessary.
5 VS Code networking settings that respect Clash
VS Code honors the same keys other Electron-based editors inherit from the Chromium stack. In user settings.json, review http.proxy, http.proxySupport, http.noProxy, and http.proxyStrictSSL. When your mixed port listens on 127.0.0.1:7890, a typical pattern is "http.proxy": "http://127.0.0.1:7890" with "http.proxySupport": "override" during debugging, then a gentler mode once stable. Populate http.noProxy with RFC1918 ranges, internal Git remotes, and private package registries so sensitive metadata never accidentally rides a public exit.
Extensions that spawn Node child processes may read shell environment variables instead of settings.json. Mirror proxy exports in the profile your integrated terminal loads, and verify non-interactive shells inherit them—Electron-launched terminals sometimes skip aliases you rely on interactively. If only part of Roo Code obeys the proxy, suspect split inheritance rather than a broken rule.
On Linux, also confirm desktop-wide proxy integration actually applies to your session; some tiling window manager setups ignore GNOME proxy keys until you wire them manually. A short curl -I https://marketplace.visualstudio.com from the same environment VS Code uses is worth more than hours of guessing.
6 Open VSX, VSCodium, and registry mirrors
Not every build uses Microsoft’s gallery. Open VSX at open-vsx.org powers many community distributions and VSCodium-style builds. If your workflow targets VSCodium or enterprise mirrors, repeat the log exercise against that registry: metadata, tarball downloads, and signature checks may hit different CDNs. Treat those suffixes like first-class entries beside marketplace.visualstudio.com so Cline installs remain one-click affairs.
Some teams air-gap machines and sync extensions from an internal artifact server. In that mode, Clash rules for public marketplaces matter less, but model APIs for Cline may still require outbound paths. Document both flows separately to avoid copying a home-office YAML into a lab network verbatim.
7 Verification: logs, DNS alignment, and when to enable TUN
Misroutes usually surface as partial failures: the marketplace HTML loads while blob downloads stall, or model streaming works in curl but not inside the extension host. Start by filtering Mihomo logs for the exact hostname shown in the error toast. If the core never sees the name, Chromium or OS DNS is still bypassing your stack—see our Chrome and Edge secure DNS article when browsers and FakeIP fight for authority, and the Meta DNS leak prevention guide for resolver design inside the proxy.
When well-behaved HTTP clients are not enough—Go tooling, some language servers, or stray binaries—TUN mode captures traffic earlier. The Clash Verge Rev TUN tutorial covers guardrails; after enabling TUN, re-run the extension install test with system proxy temporarily disabled to confirm the virtual interface still carries VS Code flows.
For HTTPS hostname drift where IP-based rules misfire, the Meta Sniffer guide explains recovering SNI for routing decisions. Sniffer settings are orthogonal to marketplace suffix lists—you may need both on noisy networks.
8 FAQ
- Does Cline ship its own proxy? It ultimately relies on the editor and OS stack. Align VS Code proxy settings, environment variables, and Clash rules together.
- Why do installs fail while browsing works? The HTML and the VSIX blob often use different hostnames. Add the CDN suffix you see in logs, not only
marketplace.visualstudio.com. - Is OpenAI the only domain I need for Roo Code? Only if OpenAI is your sole provider. Most real setups mix vendors; track the endpoints you configured, not a generic headline list.
- Will GEOIP catch model APIs? Rarely reliable. Prefer explicit suffix rules for inference domains, then fall back to broader logic.
- How is this different from Windsurf? Windsurf is another standalone product surface; compare with our Windsurf routing article when the executable is not stock VS Code.
9 Wrap-up
The 2025–2026 conversation around Cline and Roo Code is less about a single magic hostname and more about returning to solid fundamentals: VS Code marketplace and CDN paths must be as well routed as the model APIs those extensions call. Expressing both families with DOMAIN-SUFFIX entries and curated rule providers keeps your Mihomo graph readable, reviewable, and safe to share with teammates who run the same extensions but different providers.
Compared with chasing per-app VPN toggles, a maintained Clash profile gives you one place to evolve policy as Microsoft renames CDNs or as you rotate API vendors. Pair this guide with the editor-specific articles linked above when your stack mixes Copilot, Cursor, and classic OSS extensions on one workstation. When you are ready to standardize installers for the whole team, our curated builds on the download page stay the recommended front door—use upstream GitHub for license and source review, not as the only distribution story for colleagues who need a binary today.
Once marketplace installs, updates, and agent prompts share the same predictable egress, the extensions can fade into the background and let you focus on code again—which is exactly what a good proxy stack should deliver.
