VS Code Extension

Context synchronization in this source checkout is extension 0.9.10, paired with the matching router. Marketplace 0.9.9 uses a separate legacy sync path and can display a 40K fallback when its application-key lookup fails. Do not downgrade to the Marketplace 0.9.8 build. Build/install the source VSIX below for explicit sync diagnostics; a GitHub merge does not publish or install an extension.

The Hermes Router extension connects Copilot Chat to your provider pool and offers optional owner controls: provider status, remote restart and the browser dashboard. Hermes routes model requests and tool calls; Copilot owns terminal commands, file edits and MCP tools.

Use the router and extension from the same current source checkout. Keep your application key for chat and the separate administrator credential for owner controls. See Context synchronization for the coordinated upgrade and verification steps.

Install from source

You need VS Code 1.104 or later and the GitHub Copilot Chat extension for the model picker. Start the router first using Setup.

From this checkout:

cd vscode-extension
npm ci
npm run check
npm test
npm run compile
npm run package

In VS Code, run Extensions: Install from VSIX…, choose hermes-router-0.9.10.vsix, then run Developer: Reload Window. For a published release, use the Marketplace listing or GitHub releases; check that release’s migration notes before mixing versions.

Connect chat with an application key

Open the router’s browser dashboard, sign in using ADMIN_API_KEY from your local configuration, and open Connect. Create an application key, copy it, and optionally send the explicit small test request. An upstream charge may apply. Existing PROXY_API_KEYS remain valid for inference.

In VS Code Settings, search for hermesRouter:

Setting	Value
hermesRouter.baseUrl	Router origin, such as http://localhost:8319. A trailing /v1 is accepted. Use HTTPS or a local SSH tunnel for a remote router.
hermesRouter.apiKey	The application key, for chat/inference only. Keep your existing setting when upgrading.
hermesRouter.hrPath	hr, or the path to the Bash CLI for Linux/macOS/WSL host controls.
hermesRouter.dockerContainer	Optional container name for controls through the host’s Docker CLI.
hermesRouter.refreshSeconds	Context limits and status refresh interval; default 10 seconds, minimum 3. Each new chat request also checks context settings.

Before opening the model picker, confirm model capacities as described below. Open Copilot Chat, open its model picker, and select hermes-router. Text streams through your configured providers. Tool calling in agent mode requires a compatible configured model; provider prices and limits still apply.

Context synchronization (0.9.10+)

Think of the dashboard as the control knob and the extension as its display. In the browser dashboard, open Settings → Context length and choose Minimum model context. The extension reads the effective input/output limits using its application key, refreshes them every 10 seconds by default, and checks again before each chat request. No administrator credential is needed for that read.

Open Confirm model capacities if discovery has not supplied both limits. Select the model, enter its provider-documented Total context tokens and Maximum output tokens, then click Save confirmed limits. Use the limits for your actual provider/account; selecting 256K cannot enlarge a smaller model. Unknown capacities are excluded from extension discovery, even in Auto mode.

The selected minimum filters eligible models and sets the extension’s target budget. Auto uses confirmed model capacities. Hermes reserves room for output and uses the lowest safe input/output budgets across the caller’s eligible models. Provider ceilings can therefore make the displayed total smaller than the selected minimum.

For one model with a confirmed 512,000-token context and at least 8,192 output tokens, choosing 256K advertises 247,808 input + 8,192 output = 256,000 total. With Auto, that model advertises 503,808 input + 8,192 output.

Saves apply to new requests without restarting Hermes. A conversation that still fits a reduced limit can continue; an oversized conversation must be shortened. A change between the final check and sending returns a retry error. Existing admitted responses keep their settings. Token counting uses a conservative UTF-8 byte estimate, including tools, so usable text may be smaller than a provider-specific tokenizer would allow.

See Context synchronization for API details, a compatibility table, and a step-by-step verification.

Optional administrator controls

Application keys no longer authorize /v1/status, global activity, configuration or remote restart. A chat connection can work while the owner panel asks for an administrator credential.

Run Hermes Router: Set Administrator Credential from the Command Palette. Enter the router’s ADMIN_API_KEY. The extension stores it in VS Code SecretStorage, scoped to the router URL, and uses it for owner status and remote restart. It does not write it to settings or replace hermesRouter.apiKey. Run the command with an empty value to remove it. Configure the credential again after changing router URLs.

The browser dashboard signs in separately using an expiring HttpOnly session. Restarting the router signs browser sessions out. Never paste the administrator credential into an application-key setting, SDK snippet or shared workspace configuration.

Command	Behavior
Open Dashboard	Owner provider status in the editor. Requires the SecretStorage administrator credential.
Open Web Dashboard (browser)	Opens /dashboard; Providers, Connect, Activity and Settings remain there.
Refresh Status	Refreshes the owner panel; a public health check helps distinguish an unreachable router from missing owner access.
Set Administrator Credential	Stores or removes the optional router-scoped owner credential.
Restart Router	Uses local hr restart, host docker restart, or the authenticated remote restart API, depending on settings.
Run Doctor (diagnose)	Runs hr doctor on a supported local/Docker host. Remote routers show host instructions.
Update to Latest	Runs the local update helper. Docker users pull/rebuild and recreate their container; remote routers require host access.
Import Codex (ChatGPT) Login	Runs the local/Docker import helper. Remote routers require host access.

Provider credentials, model overrides, key rotation, optional features, application access and instances are managed in the browser dashboard. See Monitoring.

Docker and Windows controls

With a router in Docker, set hermesRouter.dockerContainer to its container name. Restart Router then runs docker restart <container> on the host. Doctor and Codex import require the :cli image and the host Docker CLI. Updating an image requires pulling/rebuilding and recreating the container; the extension reports this instead of running an in-container update.

The browser/remote restart endpoint only reports success on an installation with a supported restart helper. Native Windows and a minimal Docker image can return 409 with a remedy; a container restart policy does not make a missing helper supported. Use docker restart <container> on the host, or stop the native Windows router and rerun start.ps1 in PowerShell. See Setup for the persistent Compose configuration and native Windows installation.

Native Windows supports browser configuration and chat. The extension’s local hr controls still require Linux/macOS/WSL, or Docker controls through the host Docker CLI. A remote owner credential does not grant SSH or host command access.

Troubleshooting

• Chat prints <invoke ...> or stops after a file-reading instruction: update the router. Older Anthropic adapters dropped tool definitions, native tool_use responses, and tool results. The fix preserves them for streamed and ordinary requests, so Copilot can run its selected tools and continue. Start a new chat after updating to avoid reusing the broken conversation. XML-looking text is never executed as a tool call. Ask mode supports read-only codebase research; choose Agent when you want edits or commands. See VS Code agent harnesses and Anthropic tool use.
• Three ready providers, but only one receives requests: context size, tool support, access scopes and health determine eligibility. At a 1M minimum, a 131K model is excluded even for a short prompt. Unknown capacities are also excluded. Save documented capacities in Settings, or choose a smaller minimum if you want smaller models in the pool. See verified model limits.
• Forced tool use rejected by Claude: Hermes preserves required/named tool choices; model support varies. Sonnet 5.5 rejects forced tool use, so use auto for that model. Hermes does not silently weaken a required tool call to an optional one. See Anthropic tool choice restrictions.
• Chat returns 401: check hermesRouter.apiKey is a live application key for this router. A revoked key fails new requests immediately.
• Owner panel returns 401/403 or asks for a credential: run Set Administrator Credential and use ADMIN_API_KEY. Changing the application key will not grant owner access.
• Router unreachable: check baseUrl, the running process and /health. A live process can still have no usable provider; verify a real request from Connect.
• Still shows about 40K in Marketplace 0.9.9: check hermesRouter.apiKey is an active application key from dashboard Connect, not the dashboard administrator key. HTTP 401 on /v1/models triggers its silent fallback. Keep hermesRouter.contextWindow at 0. Source 0.9.10 reports sync failures instead of inventing a budget; run Hermes Router: Check Context Sync to see the connected URL, actual limits, or error.
• Router update required / client-config returns 404: update the router as well as the extension; a container restart alone does not replace its image.
• Model missing from Copilot’s picker: check VS Code/Copilot Chat requirements, the application key’s scope, and confirmed context/output limits in the browser dashboard. At least one eligible model must fit the minimum; lower the minimum or add a compatible model if necessary.
• Dashboard stuck on “Loading…”: reload after installing the current VSIX, which retains the published 0.9.7 dashboard fix. Owner status still requires Set Administrator Credential.
• hr not found: use the documented native Windows start/stop commands, WSL, or configure Docker controls. Browser configuration and inference do not require hr on the editor’s host.
• Restart rejected: follow the returned remedy. Success is only reported after a successful API response; a network failure is not treated as a completed restart.

See Setup, Providers and Monitoring for router configuration.