Modelglass Cost-Aware Router

A VS Code extension that routes a task to the cheapest LLM that clears a confirmed benchmark bar, using the live Modelglass pricing and capability feed. Since v0.3.0 it can also execute the call directly against your own provider key — a fully client-side, BYOK (bring-your-own-key) router: no Modelglass proxy in the request path, ever.

There are two distinct routing commands in this extension — see Commands below for exactly how they differ. Route Task (the original MVP command) only recommends a model; it never calls any provider API. Run Task (new in v0.3.0) executes the call, using a provider key you supply.

Route Task to Cheapest Capable Model

1. Run Modelglass: Route Task to Cheapest Capable Model from the Command Palette.
2. Describe what you're about to do; the extension infers a starting task type (coding / writing / general) from your active file's language — always overridable.
3. It fetches the current LLM pricing/capability feed and recommends the cheapest model that clears the relevant quality bar — coding tasks are ranked by SWE-bench Verified, writing/general tasks by instruction-following rating. Recommendation only — nothing is executed.

Run Task on Cheapest Capable Model (BYOK router — Starter / Pro)

1. Configure a provider key first — Modelglass: Set Provider API Key (see Provider API keys below).
2. Run Modelglass: Run Task on Cheapest Capable Model, pick one of nine task categories (bug fix/debug, new code generation, terminal/CLI/DevOps, library-aware feature work, refactor, test generation, documentation generation, chat/explain, autocomplete), and describe the task.
3. The extension ranks your configured provider's models against Modelglass's live benchmark/capability feed (SWE-bench Pro/Verified, Terminal-Bench 2.1, Aider Polyglot/LiveCodeBench, or BigCodeBench, depending on category — with a qualitative capability-rating fallback for categories no benchmark covers well) and calls the top-ranked model directly, using your own key. Supports OpenAI, Anthropic, DeepSeek, xAI, Mistral, Groq, Together AI, and OpenRouter.
4. Starter (one configured key): one execution attempt. A failure (invalid key, rate limit, network/provider error) is reported clearly — no automatic retry.
5. Pro (multiple configured keys, via Modelglass: Add Provider API Key): on a failure, automatically retries the next-best-ranked model on a different configured provider (never the same provider twice), up to one attempt per configured provider. Pro also unlocks an optional .modelglass/routing-rules.json file in your workspace to override the default ranking per category — exclude a provider, force cheapest-first, or set an exact model priority order. A Starter user with a routing-rules.json present, or attempting to configure more than one provider key, gets a clear upgrade prompt rather than a silent failure.

Install

From the Marketplace (once published): search Modelglass Cost-Aware Router in VS Code's Extensions view, or run:

code --install-extension modelglass.cost-aware-router

From a .vsix file directly (e.g. for testing a pre-release build):

code --install-extension path/to/cost-aware-router-0.1.0.vsix

First run

No account or setup needed: the extension silently provisions its own free Modelglass API key the first time you run a command, stored in VS Code's SecretStorage — never in a settings file or anything synced elsewhere. Look in the Modelglass output channel (View → Output) to confirm it provisioned successfully. If the API is unreachable, it offers to retry or let you enter a key manually instead. This free Modelglass key is what Run Task also checks against to determine Pro vs Starter access — it's the same key, not a separate credential.

Provider API keys

Run Task needs a key from whichever LLM provider(s) you want it to call — these are entirely separate from the free Modelglass key above, and are never sent to Modelglass, only to the provider itself.

• Modelglass: Set Provider API Key — the Starter flow: pick a provider, paste its key. Exclusive — setting a new provider's key replaces whichever one was configured before (with a confirmation warning).
• Modelglass: Add Provider API Key — the Pro flow: pick a provider, paste its key, alongside any other already-configured provider(s) — this is what builds the fallback chain. Adding a first key, or rotating an already-configured provider's own key, is never gated; adding a second simultaneous provider requires Pro.

Both store into VS Code's SecretStorage, same mechanism as the free Modelglass key.

Commands

Scope

• Route Task is LLM routing only (coding + writing/general), recommendation only, no execution — the original MVP command, unchanged since v0.1.0. Run Task (BYOK router, v0.3.0+) is also LLM-only, but ranks across nine finer-grained task categories and actually executes. Neither routes image/video/audio — Compare Two Models is the only cross-modality (image/llm/video/audio) command.
• Run Task doesn't offer the composite "agentic multi-step" category — that needs its own subtask-decomposition UI, not built yet. It routes one task to one category per invocation, same "once per invocation" scope as Route Task.
• Only eight providers have a working execution adapter today: OpenAI, Anthropic, DeepSeek, xAI, Mistral, Groq, Together AI, OpenRouter. A provider-API model-identifier heuristic is used (documented in src/provider-execute.ts) since Modelglass's registry doesn't carry a dedicated field for a provider's literal model string — OpenRouter and Together AI are the two providers where this heuristic is least reliable.
• No MCP exposure yet — Run Task's routing/execution is VS Code-only for now; exposing it as an MCP tool for agent frameworks outside VS Code is a possible future direction, not built.
• No escalation/usage-logging (the CLI's report command's feature set) — out of scope for this extension.

Relationship to cost-aware-vscode-router

The core selection logic behind Route Task (src/lib.ts) is vendored from modelglass-router-examples/cost-aware-vscode-router/src/lib.ts — same pricing/quality-bar logic, same tests. There's no published shared package to depend on instead, so this is a deliberate copy, kept in sync by hand. requireApiKey() (that repo's CLI-only key handling, which calls process.exit(1) on failure — not safe inside an Extension Host) is replaced entirely by src/auth.ts.

Run Task (src/routing-engine.ts, src/run-task*.ts, src/provider-*.ts, src/routing-rules*.ts, src/pro-gate*.ts) is original code written for this extension — not vendored from anywhere.

Development

npm install
npm run typecheck
npm test
npm run build      # bundles src/extension.ts -> dist/extension.cjs via esbuild
npm run watch       # same, rebuilding on change
npm run package     # builds + bundles a .vsix via vsce

Press F5 in VS Code (with this folder open) to launch an Extension Development Host for manual testing.

License

MIT — see LICENSE. Consistent with modelglass-router-examples (SCO-170) — this extension is meant to be installed, read, and adapted.