Agent Architecture

Google Antigravity

Google Antigravity is a desktop and platform host distinct from Antigravity CLI. It should be described as an agent-first multi-agent development platform with desktop app, SDK, plugins, hooks, skills, subagents, and a unified backend, while keeping source-light caveats visible.

Source reviewed #18Checked 2026-07-06

Setup guide Source

Run type

Desktop

Adapter

json-stdio

Source

Closed / product homepage

Stars

Frontier

Archive Context

This page is one host entry inside the full architecture archive and keeps multi-surface products visible instead of collapsing them into a single run type.

42 host archive

Host page

antigravity

Run cohort

Desktop: 9

Archive route

/agents

Host Surface Perspectives

The host is the primary architecture boundary. Each runnable surface below separates what the host owns from what agent-connector can safely install for Google Antigravity.

1 surface entry

Desktop

desktop

Host entry: A desktop app or standalone editor owns window state, sign-in, project indexing, embedded terminal behavior, and local product storage.
Host owns: The desktop host owns orchestration UI, model routing, approval UX, background jobs, and any cloud or app-store managed extension points.
Connector role: agent-connector can write documented workspace/global config and content files, but it does not replace the desktop runtime or UI shell. Current wired connector surfaces: MCP server, Hooks, Commands, Skills, Memory.
Implementation consequence: Desktop surfaces need source-review separation because product pages often document capabilities while runtime state lives in app-managed storage. No visible host-native gap is currently tracked for this surface.

Verified Architecture

Source-checked on 2026-07-06. These notes are intentionally separate from the generated surface matrix below.

Sequence #18

Source pass

Current source review findings are kept as the first architecture section so readers can separate external evidence from the generated local coverage model.

The rendered official page describes Antigravity as a next-generation agent platform and exposes editor, terminal, dashboard, repository, and merge-related signals.
This adapter row is the desktop/product surface, so the diagram should not collapse it into the separate Antigravity CLI entry point.
Because the official product page is high-level, page claims should focus on entry point and orchestration shape while leaving hook details to adapter evidence.

Runtime boundary

The adapter target is the desktop/platform host, not the CLI row. Antigravity owns multi-agent task orchestration, desktop UX, backend session state, SDK workflows, and plugin distribution.

Public reporting describes Antigravity 2.0 as an agent-first platform with an updated desktop app.
The CLI exists beside the desktop app and should not be merged into one adapter claim.
The official site is a source-light SPA in this pass.

MCP registration

MCP support should remain evidence-bounded. Antigravity's plugin and extension language may cover tools, but the page should not infer local MCP file registration without current official docs.

Desktop tool registration may be platform-managed rather than file-managed.
SDK workflows could expose integrations that are not MCP servers.

Hook bridge

Hooks are reported as part of the Antigravity migration feature set, but the desktop host needs its own event documentation before agent-connector treats it as a wired hook target.

Desktop hooks may differ from CLI hooks if a unified backend mediates events.
Hook support should be tagged as source-light until official event schemas are available.

Content surfaces

Antigravity content surfaces include skills, subagents, plugins, SDK workflows, background tasks, desktop sessions, and migration artifacts from Gemini CLI. These should be displayed as platform surfaces.

Plugins are the renamed extension distribution surface in public reporting.
Skills and subagents are separate from MCP and should get their own inventory chips.

Marketplace and host-only affordances

The host-only affordance is a Google-managed multi-agent platform intended to replace or absorb Gemini CLI and Code Assist individual usage. The archive should make migration and source-light status unmistakable.

Desktop app, CLI, SDK, and plugins should appear as separate architecture nodes.
Source-light status protects the page from overstating unpublished internals.

Host-specific shape

Google Antigravity desktop is a json-stdio desktop agent host with MCP, hooks, commands, skills, and memory tracked, while statusline and subagent file surfaces stay separate from the CLI row.

Form factor: Desktop.
Native surfaces: MCP server, Hooks, Commands, Skills, Memory.
Wired surfaces: MCP server, Hooks, Commands, Skills, Memory.
Visible gaps: none.

Hooks

Hooks enter through a host-launched command that exchanges event JSON over stdio.

MCP

The adapter writes this host's native MCP registration dialect, including its root key, scope, transport fields, and environment syntax.

Memory

Managed memory text is written into the rules or memory file this host actually reads, with ownership markers for reversible uninstall.

Marketplace and affordances

A marketplace or plugin-driver path is wired, so install/update/uninstall can be driven rather than only emitted as files.

Runtime handlers: none.
User-visible affordances: Users see managed commands + skills + memory surfaces after install; runtime-only surfaces stay behind the host boundary..

Known Limits

Official Antigravity documentation was not sufficiently text-exposed in this pass.
Keep desktop and CLI rows separate.
Reported migration claims need fresh checks before release or compatibility promises.

Evidence checked

Google Antigravity Antigravity 2.0 report Antigravity desktop report Google Antigravity official site

Architecture Diagram

Host-specific flow for the Desktop surface.

json-stdio

1
Entry point: Desktop
Desktop or standalone editor app reads global/product storage plus workspace files before handing control to its embedded agent runtime.
2
Connector package
defineConnector package declares server, hooks, content, memory, and actions.
3
Adapter module: antigravity
json-stdio renderer at src/adapters/antigravity/index.ts.
4
Native host artifacts
Adapter writes MCP config + hook config + content files + memory/rules + marketplace bundle through this host's native file, package, or marketplace surface.
5
Runtime boundary
host launches JSON-stdio hook command
6
User-visible surface
Users see managed commands + skills + memory surfaces after install; runtime-only surfaces stay behind the host boundary.
7
Coverage ceiling
5/5 native surfaces wired. No visible host-native gap in the current coverage matrix.

Component Diagram

Static parts of the Google Antigravity integration and which side owns each one.

Google Antigravity host
Desktop surface owns the model loop, UI shell, config discovery, and native lifecycle for this integration.
agent-connector package
Normalizes connector declarations into MCP, hook, memory, content, and action payloads before delegating to a host adapter.
antigravity adapter
Implements the json-stdio translation layer in src/adapters/antigravity/index.ts.
Native artifacts
Adapter writes MCP config + hook config + content files + memory/rules + marketplace bundle through this host's native file, package, or marketplace surface.
Runtime bridge
host launches JSON-stdio hook command
User-visible surface
Users see managed commands + skills + memory surfaces after install; runtime-only surfaces stay behind the host boundary.

Runtime Sequence Flow

Message order from install to runtime for the Desktop surface.

1 · User / project
Choose host adapter
Install or update starts against Google Antigravity; the selected surface is Desktop.
2 · agent-connector
Resolve connector declaration
The package reads connector metadata and routes it to the antigravity adapter instead of exposing a generic host contract.
3 · antigravity adapter
Render host-native shape
Adapter writes MCP config + hook config + content files + memory/rules + marketplace bundle through this host's native file, package, or marketplace surface.
4 · Google Antigravity
Host loads artifacts
host launches JSON-stdio hook command
5 · Agent runtime
Run through host boundary
Users see managed commands + skills + memory surfaces after install; runtime-only surfaces stay behind the host boundary.
6 · Coverage matrix
Expose remaining ceiling
5/5 native surfaces wired. No visible host-native gap in the current coverage matrix.

Architecture Archive

The same five study axes are rendered for every host: runtime shape, hooks, MCP, memory, and host-only affordances.

Host-specific shape

Google Antigravity desktop is a json-stdio desktop agent host with MCP, hooks, commands, skills, and memory tracked, while statusline and subagent file surfaces stay separate from the CLI row.

Form factor: Desktop.
Native surfaces: MCP server, Hooks, Commands, Skills, Memory.
Wired surfaces: MCP server, Hooks, Commands, Skills, Memory.
Visible gaps: none.

Hooks

Hooks enter through a host-launched command that exchanges event JSON over stdio.

MCP

The adapter writes this host's native MCP registration dialect, including its root key, scope, transport fields, and environment syntax.

Memory

Managed memory text is written into the rules or memory file this host actually reads, with ownership markers for reversible uninstall.

Marketplace and affordances

A marketplace or plugin-driver path is wired, so install/update/uninstall can be driven rather than only emitted as files.

Runtime handlers: none.
User-visible affordances: Users see managed commands + skills + memory surfaces after install; runtime-only surfaces stay behind the host boundary..

Special Feature Inventory

Host-specific capabilities separated from the generic surface matrix: lifecycle hooks, MCP registration, memory/rules, marketplace delivery, and UI or content affordances owned by the host.

Lifecycle hooks

Wired

Hooks enter through a host-launched command that exchanges event JSON over stdio.

MCP registration

Wired

The adapter writes this host's native MCP registration dialect, including its root key, scope, transport fields, and environment syntax.

Memory and rules

Wired

Managed memory text is written into the rules or memory file this host actually reads, with ownership markers for reversible uninstall.

Marketplace delivery

Driver wired

A marketplace or plugin-driver path is wired, so install/update/uninstall can be driven rather than only emitted as files.

Host-only affordances

2/2 wired

Wired host affordances: Commands, Skills. Host-native gaps: none. Not confirmed: Subagents, Statusline handler, Action affordances.

Source Review Notes

Latest source pass for host-specific architecture details. This is separate from generated adapter coverage and local drift guards.

Checked 2026-07-06Open review source

Google Antigravity official site

The rendered official page describes Antigravity as a next-generation agent platform and exposes editor, terminal, dashboard, repository, and merge-related signals.
This adapter row is the desktop/product surface, so the diagram should not collapse it into the separate Antigravity CLI entry point.
Because the official product page is high-level, page claims should focus on entry point and orchestration shape while leaving hook details to adapter evidence.

Evidence Map

Each host page ties public source evidence to the local adapter and drift guards that keep the rendered archive aligned with code.

Product source

Official product homepage or public tracker used when no open product repository is confirmed.

external

Open source

Local adapter implementation

Defines the install/uninstall behavior, native config rendering, capability flags, and any runtime parse/format bridge for this host.

local

src/adapters/antigravity/index.ts

Platform metadata and host-native matrix

Records the form factor, public source target, ranking source, native host surfaces, and current agent-connector coverage cells.

local

site/src/platform-data.ts

Architecture drift guard

Asserts that every registered host has a page, diagram, host-specific brief, source link, form-factor band, and adapter-aligned surface data.

local

tests/docs/platform-drift.test.ts

Marketplace driver registry

Shows this host has a drivable package/plugin install path beyond direct native-file writes.

local

src/core/marketplace-drivers/registry.ts

Runtime Shape

Hooks are dispatched through a host-launched command. The adapter parses host JSON, calls the connector handler, and formats the reply back to the host contract.

MCP registration: Wired through this adapter
Hook bridge: Wired

Connector Surfaces

Static content

MCP server, Hooks, Commands, Skills, Memory

Runtime handlers

No runtime handler surfaces wired

Surface Matrix

Wired means agent-connector installs it now. Host native marks support we know about but have not wired yet.

SurfaceStatus

MCP server

Static content

agent-connector installs this surface today.

Wired

Hooks

Static content

agent-connector installs this surface today.

Wired

Commands

Static content

agent-connector installs this surface today.

Wired

Skills

Static content

agent-connector installs this surface today.

Wired

Subagents

Static content

No confirmed host-native surface.

N/A

Memory

Static content

agent-connector installs this surface today.

Wired

Statusline handler

Runtime handler

No confirmed host-native surface.

N/A

Action affordances

Runtime handler

No confirmed host-native surface.

N/A