Blinkk Agent Platform Chat Connector

Adds Gemini and Claude on Gemini Enterprise Agent Platform (formerly Vertex AI) to VS Code chat as a native language model provider, using your own gcloud credentials — no API keys stored in the editor, and no local proxy or background service. Usage is billed to your GCP project, not GitHub Copilot.

Install

Install from the VS Code Marketplace, or from the command line:

code --install-extension blinkk.vscode-agent-platform-connector

You can also search Blinkk Agent Platform Chat Connector in the Extensions view (Cmd/Ctrl+Shift+X).

What it does

On activation the extension registers a Language Model Chat Provider via vscode.lm.registerLanguageModelChatProvider (vendor blinkk-google-agent-platform). Its models appear in the Copilot model picker under Manage Models… → Blinkk Agent Platform Chat Connector, labeled with the active GCP project, e.g. Claude Opus 4.8 (my-project).

For each chat turn the provider:

converts VS Code's request messages (text, tool calls, tool results) into the right upstream shape — OpenAI Chat Completions for Gemini, Anthropic Messages for Claude;
attaches a fresh Google access token from gcloud (ADC or the isolated store);
streams the response back as text and tool-call parts.

A Blinkk Agent Platform Chat Connector status bar item shows the active project/auth and today's estimated cost, and its output channel mirrors provider logs.

Prerequisites

Before the connector can serve any model you need three things set up in the GCP project that usage will be billed to. Each step links straight to where you can satisfy it.

Install the gcloud CLI and sign in.
- Install: https://cloud.google.com/sdk/docs/install
- Then either run gcloud auth application-default login (ADC mode) or use the extension's Sign In (isolated credentials) command.
Enable the Vertex AI / Agent Platform API (aiplatform.googleapis.com) in your project.
- Enable it here: https://console.cloud.google.com/apis/library/aiplatform.googleapis.com
- Your account also needs the Vertex AI User role (roles/aiplatform.user). Grant roles at: https://console.cloud.google.com/iam-admin/iam
Enable the models in Model Garden. Gemini models are usually available by default, but Claude models must be explicitly enabled and their terms accepted.
- Open Model Garden: https://console.cloud.google.com/agent-platform/model-garden
- Enable each Claude model you intend to use (e.g. Claude Opus 4.8, Claude Sonnet 4.5).

Finally, set the project in the extension settings (blinkkAgentPlatformConnector.project) and confirm the models with the Check Models command.

Settings

All settings live under blinkkAgentPlatformConnector.*:

Setting	Description
`project`	Required. GCP project billed for usage.
`authMode`	`adc` (default) or `isolated`.
`authAccount`	Optional gcloud account to pin.
`geminiLocation`	Vertex location for Gemini (default `global`).
`claudeLocation`	Vertex location for Claude (default `global`).
`customModels`	Extra models to expose beyond the built-in defaults.

Each setting can also be overridden by a GOOGLE_AGENT_PLATFORM_* environment variable.

Cost tracking

The connector keeps a local, per-day estimate of how much your chat usage costs. It never queries the GCP billing API — everything is computed and stored on your machine. How it works:

Token counts come from the API. At the end of each chat turn the upstream response reports input and output token usage (Gemini's usage field, Claude's message_start/message_delta metadata).
Cost is estimated from per-model pricing. Each model carries an approximate price in USD per 1M tokens, and cost is (inputTokens / 1M × inputPrice) + (outputTokens / 1M × outputPrice). You can override or set pricing for your own entries via the customModels setting.
A daily tally is persisted. Tokens, request count, and estimated cost are accumulated into a single record keyed by the local calendar day and saved to ~/.config/blinkk-vscode-google-agent-platform-connector/usage.json. The tally resets automatically at local midnight.
It's shown in the UI. Today's estimated cost (and request count) appears in the status bar hover tooltip and in the status menu (click the status bar item).

The figures are an estimate — pricing is approximate and tokens are whatever the API reports. Use the official pricing page and your GCP billing reports for accurate numbers.

Commands

All commands are under the Blinkk Agent Platform Chat Connector category.

Command	Description
`Settings`	Open the extension's settings in the Settings UI.
`Show Logs`	Reveal the output channel.
`Check Models`	Probe the configured models against Vertex.
`Sign In (isolated credentials)`	Populate the connector's isolated credential store (independent of ADC).

Requirements

Requires VS Code >= 1.104 (the Language Model Chat Provider API is finalized there) and the gcloud CLI on your PATH. Credentials come from gcloud (ADC or the connector's isolated store); the extension does not embed secrets.

Privacy & telemetry

This extension collects no telemetry. It stores no secrets in the editor.

Authentication uses your local gcloud credentials; access tokens are cached in memory only and never written by the extension.
The cost/usage tally is computed and stored locally under ~/.config/blinkk-vscode-google-agent-platform-connector/ and is never transmitted anywhere.
Your prompts and chat content are sent only to Google Cloud's *aiplatform.googleapis.com endpoints to serve your requests, billed to the GCP project you configure.

See SECURITY.md for how to report vulnerabilities.

Development

npm install          # or pnpm install
npm run typecheck    # tsc --noEmit
npm run lint         # eslint
npm test             # vitest unit tests
npm run build        # esbuild → dist/extension.cjs

Press F5 in VS Code to launch an Extension Development Host with the extension loaded.

Layout

src/extension.ts — VS Code host: registers the provider, status bar, commands.
src/vertex.ts — dependency-free Vertex client (auth, streaming, config).
src/catalog.ts — model catalog, config schema, pricing, URL helpers.
src/usage.ts — local daily usage + cost tracking.
bin/ — standalone CLI for --login / --check (runs raw .ts on Node ≥24).
test/ — Vitest unit tests.

Packaging & publishing

npm run package        # → vscode-agent-platform-connector.vsix

Install the .vsix locally with Extensions: Install from VSIX…, or:

code --install-extension vscode-agent-platform-connector.vsix

To publish to the Visual Studio Marketplace, you need a publisher (blinkk) and a Personal Access Token:

npx vsce login blinkk
npm run publish:vsce

Optionally also publish to Open VSX (for Cursor / VSCodium users):

npm run publish:ovsx -- -p <OPEN_VSX_TOKEN>

License

MIT