dsh-subscription-antigravity

Reuse a Google Antigravity subscription (Google AI Pro / Ultra) as model providers in DeepSeek Harness. Sign in with your Google account once; the plugin provisions an antigravity model route with Gemini, Claude, and GPT-OSS models from Cloud Code Assist and serves them to the harness through a loopback OpenAI-compatible proxy.

Protocol shape follows the pi-antigravity reference implementation. Unofficial integration — not affiliated with or endorsed by Google. Use only with an account and services you are authorized to access.

Install

npx --yes github:shaomingbo/dsh-subscription-antigravity#v0.1.3

The no-argument installer adds the bundle to the web profile (fixed tag source, pnpm install --ignore-scripts, atomic manifest writes, rollback on dependency-install failure). It never stops or restarts DSH — when it finishes, restart DSH manually and hard-refresh the Web GUI.

Other commands:

npx --yes github:shaomingbo/dsh-subscription-antigravity#v0.1.3 status
npx --yes github:shaomingbo/dsh-subscription-antigravity#v0.1.3 uninstall

Options: --profile (default web), --source , --help. Environment: DSH_ANTIGRAVITY_SOURCE overrides the package source.

Local development (link:)

npx --yes github:shaomingbo/dsh-subscription-antigravity#v0.1.3 install \
  --source link:/Users/you/open-source/dsh-subscription-antigravity

A link: source is for development only; switch back to the fixed tag for normal use.

Manual fallback

Edit ~/.dsh/profiles/web/package.json by hand: add "dsh-subscription-antigravity": "github:shaomingbo/dsh-subscription-antigravity#v0.1.3" to dependencies and "dsh-subscription-antigravity" to dsh.profile.bundles, then run pnpm install --ignore-scripts in the profile directory. Restart DSH and hard-refresh afterwards.

Sign in

1. Open Settings → Antigravity in the Web GUI.
2. Choose Sign in with Google — a browser tab opens the Google OAuth consent screen (PKCE; the local callback server listens only on localhost:51121).
3. After approval the tab reports success and the section shows your account. On a remote/headless browser, paste the callback URL (http://localhost:51121/oauth-callback?…) into the field provided.

Once signed in, the models below appear in the DSH model picker under the antigravity provider; selecting one makes it the default for new sessions.

Requested Google scopes: aicode, cloud-platform, userinfo.email, userinfo.profile, cclog, experimentsandconfigs. Review them before approving.

Models

Public model ids mirror the Antigravity CLI catalog; each exposes only the thinking levels the backend advertises (thinking effort maps to the backend's runtime ids — see SPEC.md):

Model	Input	Thinking
gemini-3.7-flash	text, image	low / medium / high
gemini-3.6-flash	text, image	low / medium / high
gemini-3.5-flash	text, image	low / medium / high
gemini-3.1-pro	text, image	low / high
claude-sonnet-4-6	text, image	high
claude-opus-4-6	text, image	high
gpt-oss-120b	text	medium

Model availability, entitlement, and quota are account-dependent. Quota is a shared pool; 429s surface with reset hints. The Settings section shows best-effort quota usage.

How it works

flowchart LR
    A["llm-pi-ai route
api: openai-completions"] --> B["loopback proxy
127.0.0.1:51122/v1"]
    B -->|"v1internal:streamGenerateContent"| C["cloudcode-pa.googleapis.com"]
    D["Google OAuth PKCE
(browser sign-in)"] --> E["$DSH_HOME/.antigravity-auth.json"]
    E --> B

• The plugin provisions (and repairs) one route in llm-pi-ai.providers via the settings service — per-provider merge; your own edits to models are preserved, and other providers are never touched.
• The proxy binds 127.0.0.1 only and translates OpenAI chat completions (streaming SSE and JSON) into Cloud Code Assist envelopes, including tool calls, image inputs, thinking → reasoning_content, and quota-friendly error mapping. Override the port with DSH_ANTIGRAVITY_PROXY_PORT.
• Fresh access tokens sync into the ordinary credentials seam (ANTIGRAVITY_ACCESS_TOKEN) so route resolution always has a value.
• Multi-account rotation, usage-based billing, and non-Google endpoints are out of scope.

Credential safety

• OAuth tokens live only in $DSH_HOME/.antigravity-auth.json (0600, atomic writes). They are never logged, exported, or sent anywhere except Google's OAuth and Cloud Code Assist endpoints. Upstream text in errors is redacted and bounded.
• Uninstall keeps the credential file. Delete $DSH_HOME/.antigravity-auth.json yourself for a full wipe.
• The installer only edits the profile package.json (dependency + bundle entry); it never reads credentials, never runs lifecycle scripts, and never stops/restarts DSH.

Development

npm install          # test-only tooling; the plugin itself has zero runtime deps
npm run check        # syntax checks + full test suite
npm test

The test suite covers the installer contract (temporary DSH_HOME installs, repeats, status, uninstall, malformed manifests, argument errors, rollback), the OAuth state machine, the translation layer, the loopback proxy against fakes, route provisioning, credential sync, usage, locale parity, and pack contents.

License

MIT — see LICENSE. Protocol references: SPEC.md.