Meerkat

Meerkat

A library-first Rust platform for building, hosting, and operating agents.

Quick Start • Capabilities • Surfaces • Architecture • Documentation

Meerkat provides a shared agent runtime, not a fixed agent user experience. Its Rust crates own agent execution, typed events, providers, tools, persistence, runtime control, and multi-agent orchestration. The CLI, REST, JSON-RPC, MCP, Python, TypeScript, and browser/WASM surfaces use those same contracts.

Quick Start

brew install lukacf/meerkat/rkat
export RKAT_OPENAI_API_KEY="sk-..."
rkat run "What is the capital of France? Answer in one sentence."

The Homebrew tap supports macOS and Linux. Other installation paths:

cargo install rkat
pip install meerkat-sdk
npm install @rkat/sdk
npm install @rkat/web

GitHub release assets are one archive per binary per target (rkat-<version>-<target>.tar.gz, and the same for rkat-rpc, rkat-rest and rkat-mcp), with checksums.sha256. The quickstart shows a Linux install without Homebrew. cargo install rkat builds from source and installs rkat only; see Building and deploying. The Python and TypeScript SDKs resolve a compatible rkat-rpc and can download one automatically. To move to a new release, see Upgrading.

Provider environment variables

Provider	Resolution order
Anthropic	RKAT_ANTHROPIC_API_KEY, ANTHROPIC_API_KEY
Public OpenAI	RKAT_OPENAI_API_KEY, OPENAI_API_KEY
Gemini	RKAT_GEMINI_API_KEY, GEMINI_API_KEY, RKAT_GOOGLE_API_KEY, GOOGLE_API_KEY
Azure OpenAI	Prefixed key + endpoint pair, then AZURE_OPENAI_API_KEY + AZURE_OPENAI_ENDPOINT

If both public OpenAI and only unprefixed Azure variables are present, public OpenAI wins. Setting either prefixed Azure selector makes a complete prefixed or fallback Azure key/endpoint pair the OpenAI environment default.

Meerkat's OpenAI/global catalog default is gpt-6-astra. Explicit model and binding defaults are preserved. Catalog support does not guarantee access for an API organization or support through Azure, Copilot, or custom backends. Select an available model explicitly when needed:

rkat run --model gpt-5.5 "Explain async/await"

Use another provider by selecting a matching catalog model:

rkat run --model claude-sonnet-4-6 "Explain async/await"
rkat run --model gemini-3.8-flash "Explain async/await"
rkat models

Render a requested HTML artifact in the browser:

rkat run --browser \
  "Create a one-page comparison of the REST, JSON-RPC, and MCP surfaces"

Share State Across Processes

The CLI derives a stable workspace realm by default. Bare server/SDK launches use fresh isolated realms. Pass one explicit ID when several surfaces should share sessions and config:

rkat --state-root /srv/meerkat/realms --realm team-alpha run "Draft a release note"
rkat-rpc --state-root /srv/meerkat/realms --realm team-alpha

The processes must also resolve the same physical storage provider/root. Realm identity alone does not make two unrelated host filesystems shared.

Use Persisted Credentials