Antigravity (Gemini)

The Antigravity adapter drives Google's official agy CLI headlessly behind the Adapter contract: agy --output-format json -p for one-shot runs, agy --conversation <id> -p to revise a conversation, and agy --output-format stream-json -p for incremental events — all under your own Google login.

Unofficial

Not affiliated with or endorsed by Google. This package shells out to the agy binary you already have installed and authenticated — it never impersonates the service, shares credentials, or circumvents rate limits.

Install

npm install @toragonite/agent-mesh @toragonite/agent-mesh-gemini

Requires the agy CLI installed and logged in. Antigravity keeps its credentials in the Electron app's data directory — there is no CLI login/status subcommand, so Auth below shells out instead of reading a file.

Options

new GeminiAdapter(options?) — every option defaults to the real implementation and is overridable for testing:

Option	Type	Default	Description
exec	ExecFn	nodeExec	Run-to-completion process seam.
lineStream	LineStreamFn	nodeLineStream	Streaming process seam backing stream().
binary	string	'agy'	The agy executable path or command name.
defaultAccount	Account	—	Account used when a call passes none. Its configDir sets AGY_HOME (undocumented for agy; see Behaviour notes).
env	Record<string, string | undefined>	process.env	Environment seam — the base of every child env and every env read.
authTimeoutMs	number	20000	Wall-clock cap for the agy models auth probe.
quotaTimeoutMs	number	90000	Wall-clock cap for the agy -p /usage read behind quota().
quotaCacheMs	number	60000	How long a quota() outcome (snapshot or null) is reused per account; 0 disables the cache.

Run and resume

import { Fleet } from '@toragonite/agent-mesh'
import { GeminiAdapter } from '@toragonite/agent-mesh-gemini'

const fleet = new Fleet().register(new GeminiAdapter())

// Antigravity answers a one-word prompt in ~12-15s; set timeoutMs generously
// (see Latency below).
const res = await fleet.run(
  { prompt: 'Reply with exactly: MESH-OK', timeoutMs: 60_000 },
  { policy: { prefer: ['gemini'] } },
)
console.log(res.status, res.conversationId, res.text)

// Continue that conversation by id.
const more = await fleet.resume('gemini', res.conversationId, 'Now say it backwards.', {
  timeoutMs: 60_000,
})
console.log(more.text)

You can also drive the adapter directly:

const agy = new GeminiAdapter({ binary: 'agy' /* default */ })
const res = await agy.run({ prompt: 'hello', model: 'gemini-3.6-flash-high' })

Stream

const agy = new GeminiAdapter()
for await (const ev of agy.stream({ prompt: 'Write a haiku about routing.', timeoutMs: 60_000 })) {
  if (ev.type === 'text') process.stdout.write(ev.text)
  else if (ev.type === 'usage') console.error('usage', ev.usage)
  else if (ev.type === 'done') console.error('\ndone', ev.result.status, ev.result.conversationId)
  else if (ev.type === 'error') console.error('error', ev.message)
}

Streaming maps agy --output-format stream-json to agent-mesh RunEvents: the init event only records the conversation id; only an agent_response step with a non-empty text_delta becomes a text event (other step types — user_input, checkpoint, … — are skipped, since the contract has no event for them and their per-step usage is partial, not authoritative); the terminal result event emits a usage event followed by a done event carrying the same RunResult a non-streaming run() would produce. An empty prompt throws synchronously at the stream() call, before any process spawns. If the stream ends with no result event: a timeout yields a done result with status: 'incomplete' (never an error event); a non-zero exit yields an error event with the exit code and the child's stderr tail.

Models

availableModels() returns a static catalog and spawns nothing, because Fleet.route() calls it on the routing hot path:

id	latency	note
gemini-3.6-flash-high	fast
gemini-3.6-flash-medium	fast
gemini-3.6-flash-low	fast
gemini-3.5-flash-high	fast
gemini-3.5-flash-medium	fast
gemini-3.5-flash-low	fast
gemini-3.1-pro-high	slow
gemini-3.1-pro-low	slow
claude-sonnet-4-6	fast	resold — selecting it spends Anthropic quota, not Gemini's
claude-opus-4-6-thinking	slow	resold — selecting it spends Anthropic quota, not Gemini's
gpt-oss-120b-medium	fast	resold — selecting it spends the provider's quota, not Gemini's

Resold models

Three catalog entries are reachable through agy but bill an other vendor's quota, not Google's. Routing another vendor's quota through the Gemini adapter defeats the point of a multi-vendor fleet — prefer registering that vendor's own adapter instead.

There is no auth-mode gating — every entry is selectable under one Google login. The latency classes are a provisional pin (a best guess at interactive-vs-deep-reasoning behavior, not measured). No entry is marked default: when a task names no model, run() omits --model and the CLI applies its own default — claiming a default here would be false. A model id outside this catalog still runs, with a model <id> not in known catalog note on the result.

Static vs live

availableModels() is the fast, hermetic path for routing. The authoritative but slow counterpart is fetchLiveModels(), which runs agy models, skips the Fetching available models... chatter line, and parses each TAB-separated id\tlabel row:

import { fetchLiveModels } from '@toragonite/agent-mesh-gemini'
const live = await fetchLiveModels() // ModelInfo[] — or [] on any failure

Any failure (spawn error, non-zero exit, timeout, unparseable output) resolves to []; it never throws.

Auth

authStatus() runs agy models — the only auth probe Antigravity exposes, since there is no readable local credential file and no status/login subcommand. Exit 0 with at least one parseable model line reports { loggedIn: true, mode: 'google' }; anything else (non-zero exit, missing binary, timeout, unparseable output) reports { loggedIn: false }. It never throws and never returns a detail — the CLI exposes no account identifier.

This costs a network round-trip, so it is deliberately not on the routing path — only availableModels() (static) is.

Quota

quota() asks agy itself. It runs agy -p /usage --output-format json, which agy (1.1.11 and later) answers in print mode without an agent turn and without spending quota — agy fetches the numbers with its own login, so this adapter never reads, holds, or refreshes a token. capabilities.quota is true.

const snap = await new GeminiAdapter().quota()
// { vendor: 'gemini', allowed: true, windows: [
//     { label: 'gemini-weekly', usedPercent: 0, resetAt: '2026-10-20T07:57:54.000Z' },
//     { label: 'gemini-5h',     usedPercent: 0, resetAt: '2026-10-15T15:10:03.000Z' },
//     { label: '3p-weekly',     usedPercent: 0, resetAt: '2026-10-22T10:10:03.000Z' },
//     { label: '3p-5h',         usedPercent: 0, resetAt: '2026-10-15T15:10:03.000Z' } ],
//   raw: { groups: [...] } }

• Windows. One per enabled bucket, groups in order, then buckets in order. On agy 1.3.5 the "Gemini Models" group has gemini-weekly and gemini-5h, and the "Claude and GPT models" group (the resold models) has 3p-weekly and 3p-5h. label is the bucket id (else <group name> <window>). usedPercent is (1 − remaining_fraction) × 100, rounded to one decimal and clamped to 0..100. resetAt is the bucket's RFC 3339 reset_time as an ISO instant.
• Left out, never reported as 0. A disabled bucket; a bucket that carries only a remaining_amount (there is no limit to divide it by) or neither field (an amount of 0 with no fraction is unknown, not exhausted); a remaining_fraction above 1.
• allowed is derived per model group's windows: false when any window is at 100%. That includes the resold-model windows, so an exhausted 3p-* window gates the whole adapter. raw is the command.data object.
• null ("headroom unknown") on any failure — not logged in, an API-key / ADC session, a non-zero exit, an AGY_ERROR: or error: line, a status other than SUCCESS, a body of another shape, no usable bucket, more than 1 MiB of stdout, or the timeout. The Fleet treats null as "headroom unconfirmed" and still considers the adapter; it is never a fabricated { allowed: true, windows: [] }. quota() never throws.
• Cost and bounds. Each read boots agy's language server (a few seconds). The read times out after 90 s (quotaTimeoutMs; the whole process group is killed). Its outcome — snapshot or null — is cached for 60 s (quotaCacheMs; 0 turns the cache off). Per adapter instance and per account at most one read runs at a time (a concurrent caller waits for it). The child is started through the adapter's exec seam with the same account env as run(), stdin on /dev/null, and a private per-user working directory, <os tmpdir>/agent-mesh-agy-usage-<uid> (on a platform without a uid, -<username>, sanitized; since 0.1.4 — before, one name was shared by every local user). It is created 0700 and refused — the read is null, nothing is spawned — when it is not a real directory owned by this user with mode 0700.

Account isolation is not provided

agy 1.3.5 does not read AGY_HOME, so every account — including the one quota() reports on — shares agy's default login. See Behaviour notes.

Behaviour notes

• Trailing-newline normalization. agy terminates its printed answer with a newline the other agent-mesh vendors do not emit. For cross-vendor comparability, run()/resume() and the stream's done result strip exactly one trailing newline (\r\n or \n) from the final text. Interior newlines are preserved, and a second trailing newline is kept. Streaming text deltas are passed through raw — only the final assembled text is normalized.
• allowedTools is ignored. agy has no equivalent flag, so task.allowedTools is dropped and the result carries an allowedTools not supported by agy; ignored note.
• Account isolation is not provided by agy 1.3.5; all accounts share the default login. There is no documented config-dir env var for agy, and the agy 1.3.5 binary contains no AGY_HOME string. When you pass account.configDir, the adapter still sets AGY_HOME to it (so an agy that reads it some day gets it) and adds a note that agy 1.3.5 does not read it — but every account runs on, and quota() reports the usage of, agy's default login. An explicitly passed account with no configDir means the ambient login and does not inherit a default account's directory.
• Latency. A one-word answer is observed at 12–15 seconds (versus ~5s for Claude Code/Codex); agy's own --print-timeout defaults to 5m0s. Set timeoutMs generously — a timeout resolves status: 'incomplete' (it never throws), so too tight a cap silently truncates real answers.
• No secrets. No token or credential value appears in any result, note, detail, error, or raw. There are no tokens on this path, but the rule holds regardless.