feat(integrations): Gemini API inbound and one-click Antigravity app and agy CLI connection - #8742

Summary

Google's own Antigravity clients can now run through OpenCodex. One click on the dashboard (or ocx connect antigravity / ocx connect agy) points the Antigravity desktop app or the agy CLI at OpenCodex, so their requests get the same routing, account rotation across your Antigravity accounts, request log and redaction as every other client, without signing each client into one Google account at a time. Disconnect puts your own settings back exactly as they were. To make this work, OpenCodex now also accepts requests in the Gemini API format, which any google-genai SDK pointed at a custom base URL can use too.

This PR gathers two earlier drafts so they can be reviewed and merged as one change on current dev: #8732 and #8736 (now closed; their descriptions keep the full design notes). The agy connector needs the Gemini inbound, so they belong together. There is one commit per original PR, then the follow-ups listed below.

Parts

1. Gemini API inbound (was #8732).

• POST /v1beta/models/{model}:generateContent and :streamGenerateContent (also under /v1/models/...), GET /v1beta/models and GET /v1beta/models/{model}. Streaming answers SSE with ?alt=sse and a streamed JSON array without it, as the Gemini API does. countTokens and the embed methods answer a Gemini-shaped 501.

• It follows the Ollama inbound: translate to an internal Chat Completions request, run the ordinary Chat path, translate back. The plumbing both ingresses share moved into src/server/native-chat-bridge.ts; Ollama behavior is unchanged.

• Credentials: x-goog-api-key or ?key= is moved onto x-opencodex-api-key for the existing admission check and the query key is dropped, so auth-cors.ts is untouched and the key is never logged or forwarded.

• Codec in src/protocols/codecs/gemini.ts (contents, system instruction, inline images, function declarations and calls, tool config, generation and thinking config; text, thoughts, function calls, finish reasons and usage back). Error bodies use the Gemini {error:{code,message,status}} shape with fixed text; upstream text is never echoed.

2. Antigravity app and agy CLI connectors (was #8736). Both use Google's documented enterprise-gateway configuration, not token or binary replacement.

• Antigravity desktop app (2.15+): writes the gateway block (wireProtocol: "openai") and optionally models.defaultModelId in ~/.antigravity/settings.json; a user models.list is set aside while connected because it would hide OpenCodex models.

• agy CLI (1.2.15+): adds an agy shell function between # >>> opencodex agy >>> markers in the existing bash/zsh and PowerShell profiles, setting AGY_LLM_GATEWAY_* (genai) for that one command. No agy settings file is changed.

• Restore: original bytes go to a restore record in the OpenCodex config directory before the first write; disconnect writes them back byte for byte if the file is unchanged, otherwise reverts only what OpenCodex wrote. Temp-and-rename writes; a settings file that is not strict JSON is refused untouched.

• Honest status: connected, disconnected or drifted, with warnings when an organization admin_settings.json or an exported AGY_LLM_GATEWAY_URL would win over the user file.

• No secrets in client files: the URL comes from localInferenceDestination and the key is a fixed non-secret placeholder; if the bind requires a data-plane credential, connect refuses with the same advice ocx claude gives.

• Surfaces: GET /api/gateway-clients, POST /api/gateway-clients/{id}/connect|disconnect; CLI ocx connect|disconnect antigravity|agy; an Antigravity tab on the Integrations page; structure/clients/antigravity-gateway.md and a docs-site section. Provider-side google-antigravity accounts are untouched.

Follow-ups in this PR.

• /api/gateway-clients is now dispatched from src/server/management/integration-routes.ts instead of src/server/management-api.ts, so this PR no longer touches a sponsored surface. management-api.ts is unchanged from dev.

• Design review fixes (2bdbdb0d1, 319abde85): connector notes and override warnings were fixed English sentences from the server, so the Chinese (and every non-English) dashboard showed English; each note and override now carries a stable code next to its English text (notes is {code, text}[]; the English lives once in GATEWAY_NOTE_TEXT), the dashboard translates by code in all eleven locales, and the CLI prints the same English as before. "Restart Antigravity" appears once, in the result after an action, not also on the card. The default-model input shows the current models.defaultModelId (new defaultModel in the status response) and sends nothing when left unchanged. Status reads Connected / Not connected / Update needed, matching the buttons; the input width uses --prose-measure; controls are linked to their help with aria-describedby. structure/clients/antigravity-gateway.md says the route is loaded from integration-routes.ts.

Screenshots

Local test instance with fake providers and fake data.

Verification

Branch built from dev 873ec9b by squash-merging each original PR in order; the resulting tree was compared byte for byte with a real merge of dev and the original branch tips before the follow-up commits. All runs below on this head, Windows 11, with OCX_GIT_CONFIG_GUARD_CHECKOUT pointing at a directory without .git (this machine's git 2.56 rejects GIT_CONFIG_GLOBAL=NUL).

• bun run typecheck, bun run structure:check, bun run privacy:scan, bun run skill:surface:check: exit 0. src/server/management-api.ts is byte-identical to dev.

• GUI: bun run lint, bun run lint:i18n, bunx tsc -b, bun run build:gui: exit 0. GUI tests (gateway-clients-page incl. two new cases, locale-parity, fr-localization, i18n-locales, integrations-tab-coverage, integration-marks, integrations-surfaces, form-controls-rule): 108 pass, 0 fail.

• Server tests: gateway-clients 11, gateway-client-routes 4, gateway-client-command 4, management-route-registry 31 (1 skip), skill-ocx 15, ci-workflows/file-size-ratchet 9, test-layout 2; 0 fail.

• Screenshots use a throwaway home directory; the real ~/.antigravity/settings.json, .bashrc, .zshrc and PowerShell profiles were hashed before and after and are unchanged.

• Gemini and Ollama inbound, one file at a time: server/server-gemini-inbound 10 pass, responses/responses-gemini-codec 8 pass, server/loopback-listener-admission 32 pass, server/server-ollama-inbound-errors 25 pass; 0 fail.

• Full-suite exception: bun run test and the whole GUI suite were not run locally. Several worktrees share this machine and full runs time out in unrelated modules under that load. Coverage beyond the files above is left to CI; ci:full is appropriate because some covered paths are reached through subprocess-started servers and source-reading tests.

CodeRabbit round 1 (14 findings: 13 fixed, 1 declined with a reply on its thread; commits 05b233881..d21ed22ea):

• Offline ocx connect refuses before writing anything when the proxy is not running and the configured port is 0. The command help says only connect refuses data-plane credentials; status is local-only and disconnect revokes under any binding (generated skill reference regenerated).
• Connectors: an unreadable admin_settings.json reports admin-unreadable instead of throwing; agy writes the $SHELL profile even when another profile exists; UTF-16LE PowerShell profiles are written back in their encoding and any other non-UTF-8 encoding is refused; edits a user made while connected survive a reconnect and disconnect; Antigravity writes are recorded as pending first, so a failed or interrupted write still restores correctly.
• Gemini codec: VALIDATED mode no longer forces a tool call; images returned by a tool reach the next turn; nested content that cannot be represented gets a 400.
• GUI: an action whose outcome cannot be confirmed says so in all eleven locales and points to the status; cards remount per API target; locale parity now covers gatewayClients.*. Structure doc and integration guide say the agy marker block is removed whole.
• Declined: multiple allowedFunctionNames toward Anthropic is already enforced — Gemini requests go through the Chat inbound path, which keeps the allowed subset (src/chat/inbound.ts), and src/adapters/anthropic-tool-catalog.ts sends only those tools.
• Re-run on this head: the four gateway/codec test groups 17 + 5 + 10 + 10 (GUI) pass, tests/server/server-gemini-inbound.test.ts 10 pass (60 s timeout; 725 s under load); bun run typecheck, structure:check, skill:surface:check, GUI tsc -b, lint, lint:i18n: exit 0. All gateway tests use throwaway homes. src/server/management-api.ts is still byte-identical to dev.
• Merge order with feat(models): labelled capability estimates, automatic prices with their source, and a Usage page that loads #8738: that PR adds product-name logging for unknown clients (usageClientLogContext) and a guard test that fails on any client: classifyUsageClient(...) log context. The Gemini route here uses the closed label only, because the field does not exist on dev yet; whichever of the two lands second switches src/server/index/gemini-routes.ts to ...usageClientLogContext(req.headers), and the guard makes that impossible to miss.

Checklist

• Scope stays focused and avoids unrelated cleanup.

• Docs or release notes were updated when needed.

• Security-sensitive changes were reviewed for secrets, auth, and unsafe defaults.

Review readiness checklist

This PR stays in draft until every box below is ticked. Tick all four boxes once the requirements are met:

• Required local validation passed; commands, results, and any full-suite exception are documented.

• I pushed my PR to a recent dev commit (at most 10 behind; a maintainer may still ask for the exact tip before merge).

• I resolved all correct Codex and CodeRabbit findings.

• My PR is ready for review.

Summary by CodeRabbit

• New Features
  • Added Gemini-compatible model discovery, content generation, and streaming.
  • Added Antigravity and agy connections in the Integrations page and CLI, including status checks, optional default model selection, and connect or disconnect controls.
  • Connection status displays relevant configuration overrides and warnings. Disconnecting restores settings while preserving unrelated edits where possible.
  • Added localized interface text and guides for these integrations.