Meridian connects coding clients to Claude and Antigravity using your subscription. Run Pi, OpenCode or another supported client against a local API, and manage providers, requests and usage from a browser or the optional Mac app.

Claude requests run through Anthropic’s Agent SDK. Antigravity requests run through Google’s official, signed-in agy CLI. Account permissions, model availability and subscription limits still apply.

| Claude | Antigravity | | :--- | :--- | | Released · Claude Agent SDK | Preview · v1.74.0+ · Official agy CLI | | Persistent sessions, prompt caching and multiple account profiles | Streaming, client tools, conversation reuse and saved-answer recovery | | Client compatibility and setup | Pi and OpenCode setup | | Headless macOS, Linux and Windows | Authenticated acceptance on macOS arm64; Linux/Windows verification unfinished |

Quick start

For the released Claude backend, install Node.js 22+, then:

npm install -g @rynfar/meridian
claude login
meridian

Open http://127.0.0.1:3456. For OpenCode V1, run meridian setup and restart OpenCode. For Pi and other clients, follow the client setup guide. See configuration for API-key protection and Windows setup, or deployment for Docker and Nix.

Try Antigravity

Antigravity is included in Meridian 1.74.0 and later as a preview. The verified setup uses agy 1.2.7, Pi 0.72.1 or OpenCode V1 1.18.31, and macOS on Apple Silicon. Other versions need their own verification.

Install Node.js 22+ and the official Antigravity CLI. Run agy to sign in with your subscription account and disable paid overage credits in its settings. Then install Meridian:

npm install -g @rynfar/[email protected]

MERIDIAN_BACKEND=antigravity \
MERIDIAN_AGY_ALLOW_TOOL_BRIDGE=1 \
MERIDIAN_AGY_STATE_PATH="$HOME/.local/state/meridian/antigravity.sqlite" \
MERIDIAN_PORT=3457 \
meridian

Open http://127.0.0.1:3457/providers and use Connect Pi / OpenCode, or follow the CLI setup instructions. For a source build, follow the development guide. The tool bridge lets the client execute tools with its own permissions. The SQLite path enables saved state across service restarts; it does not guarantee recovery of an unfinished action.

What works

• The coding loop: incremental text, client tools, parallel tool batches, approvals, questions, cancellation and client-owned plugins/delegation.
• Model and output selection: available model/effort variants, forced tools and validated structured output.
• Client APIs: Anthropic Messages, OpenAI Chat Completions and a documented Responses subset.
• Attachments: images and public HTTPS image URLs; documents, speech and video through local conversion. These are not native media APIs.
• Continuity: warm conversation reuse, eligible completed-session restoration, history replay and bounded recovery of saved answers and tool IDs.
• Provider management: web and macOS setup, separate quota/status displays, shared navigation and activity. Native browser/subagent access requires separate explicit grants.

What is unfinished

Active-task reattachment and automatic reconciliation of uncertain tool outcomes are unfinished. Some provider-specific plugins, hosted-tool/file contracts and client versions need adapters and acceptance tests. Authenticated Linux/Windows verification is also outstanding.

The CLI does not expose exact output-token caps, numeric thinking budgets, sampling controls or every native media/reasoning feature. Meridian cannot add those guarantees through a wrapper. Upstream CLI failures can still interrupt a turn. The support and recovery checklist records what is missing, available workarounds and what would close each gap.

Desktop

The optional Mac app manages the local service, versions, plugins and diagnostics. Use Providers to navigate Claude and Antigravity; their accounts and quota windows stay separate. Request history helps track failures and activity across the service.

The desktop preview targets macOS on Apple Silicon. The first downloadable release is being prepared; use the source instructions in the meantime. To try Antigravity, connect the app to a Meridian 1.74.0+ service configured as shown above. Older Meridian versions do not include Antigravity.

Headless use remains supported. The npm package does not install Electron; Docker, Nix and existing service managers can run the same server.

How it works

Meridian translates supported client requests at the provider boundary. It keeps Claude-specific account routing and cache behavior separate from Antigravity’s CLI sessions and permissions. Antigravity generation stays on the signed-in CLI; there is no Google API-key or model-SDK fallback.

Documentation

| Guide | Contents | | --- | --- | | Antigravity setup | Models, client tools, attachments, permissions and setup | | Antigravity support & recovery | Feature status, unfinished work and recovery limits | | Claude client setup | Compatibility matrix and client configuration | | Desktop | Local preview, service ownership and platform status | | Configuration | CLI, environment variables and API-key protection | | Accounts & profiles | Claude sign-in, multiple accounts and routing | | Deployment | Docker, Nix and headless services | | Plugins | Official packages and plugin configuration | | Monitoring | Usage, request diagnostics and prompt caching | | Development | Build, test and programmatic API | | Live verification | Tested versions, flows and known failures |

Contributing

Report an issue, open a PR or join Discord. Read AGENTS.md, ARCHITECTURE.md and E2E.md before changing behavior. For Antigravity reports, include your OS, agy and client versions, the failing flow and redacted diagnostics.

Meridian is MIT licensed. Claude and Antigravity are trademarks of their respective owners. Provider asset credits.