Antigravity Setup

Google’s AI-first IDE with native MCP and skill support

Prerequisite: Install the engram binary first via Homebrew or binary download.

Antigravity is Google’s AI-first IDE with native MCP and skill support.

Add the MCP Server

1. Open MCP Store

   Click the ... dropdown in the agent panel → Manage MCP Servers

2. View raw config

   Click View raw config

3. Edit mcp_config.json

   Add to ~/.gemini/antigravity/mcp_config.json:

   {
     "mcpServers": {
       "engram": {
         "command": "engram",
         "args": ["mcp"]
       }
     }
   }
   
4. Save and restart

   Save the file. Antigravity will reload the MCP servers automatically.

Adding the Memory Protocol (Recommended)

Without the Memory Protocol, the agent has the tools but doesn’t know WHEN to use them.

Option A: Global Rule

Add to ~/.gemini/GEMINI.md:

## Memory

You have access to Engram persistent memory via MCP tools (mem_save, mem_search, mem_session_summary, etc.).

- Save proactively after significant work — don't wait to be asked.
- After any compaction or context reset, call `mem_context` to recover session state before continuing.

Option B: Workspace Rule

Add to .agent/rules/engram-memory.md in your project:

## Engram Persistent Memory

You have access to Engram persistent memory via MCP tools.

### WHEN TO SAVE

Call `mem_save` IMMEDIATELY after:
- Bug fix completed
- Architecture or design decision made
- Non-obvious discovery about the codebase
- Configuration change or environment setup
- Pattern established (naming, structure, convention)
- User preference or constraint learned

### WHEN TO SEARCH

When the user asks to recall something ("remember", "what did we do").
Also search proactively when starting work that might overlap past sessions.

### SESSION CLOSE

Before ending, call `mem_session_summary` with:
- Goal
- Discoveries
- Accomplished
- Next Steps
- Relevant Files

See Memory Protocol for the full text.

Platform-Specific Notes

macOS / Linux

Config path: ~/.gemini/antigravity/mcp_config.json

Windows

Config path: %USERPROFILE%\.gemini\antigravity\mcp_config.json

Antigravity vs. VS Code

Antigravity has its own skill, rule, and MCP systems separate from VS Code.

Do not use .vscode/mcp.json with Antigravity. Use ~/.gemini/antigravity/mcp_config.json instead.

Antigravity’s agent system:

• Skills — Reusable knowledge bundles
• Rules — Project-specific agent instructions
• MCP — Tool integrations via stdio transport

Memory Protocol Behavior

With the Memory Protocol in GEMINI.md or .agent/rules/, the agent:

• Saves proactively after bugfixes, decisions, discoveries, patterns
• Searches reactively when you say “remember” or “what did we do”
• Searches proactively when starting work that might overlap past sessions
• Closes sessions with mem_session_summary before saying “done”
• Recovers state after compaction with mem_context

Troubleshooting

MCP tools not available

Check MCP config:

# macOS/Linux
cat ~/.gemini/antigravity/mcp_config.json

# Windows
type %USERPROFILE%\.gemini\antigravity\mcp_config.json

Verify the engram server entry exists.

Binary not found

Antigravity can’t find engram command:

# Check PATH
echo $PATH

# Check binary location
which engram  # macOS/Linux
where engram  # Windows

If missing, install via Homebrew or binary download.

Agent doesn’t use memory

Check that global or workspace rules include the Memory Protocol:

# Global
cat ~/.gemini/GEMINI.md

# Workspace
cat .agent/rules/engram-memory.md

Next Steps

• Learn about the Memory Protocol
• Explore MCP Tools
• Set up Git Sync for team memory sharing