Crate agent_block_core 

agent-block-core — host runtime + Lua stdlib bridge + EventBus.

Depends on agent-block-types (error / obs) and agent-block-mcp (rmcp wrapper). The bin crate agent-block is a thin CLI on top.

Cargo features

All three are on by default, so the default build (and the agent-block CLI) keeps the full runtime surface. SDK embedders that only need a subset can opt out with default-features = false and re-enable individual axes:

Feature	Enables	Pulls in
mesh	mesh.* Lua bridge, relay connect, Ed25519 mesh identity	agent-mesh-core, agent-mesh-sdk
sqlite	sql.* / kv.* / ts.* Lua bridges (SQLite-backed)	rusqlite (bundled), mlua-batteries/{sql,kv}
mcp-http	mcp.connect_http (Streamable HTTP / SSE MCP transport)	agent-block-mcp/mcp-http → rmcp HTTP-client transports

The stdio MCP transport (mcp.connect), http.*, tool.*, sh.*, log.*, bus.*, and the embedded StdPkg blocks are always available.

When a feature is off:

• mesh: the mesh.* bridge is not registered; BlockConfig::relay_url / secret_key are accepted but ignored.
• sqlite: the sql.* / kv.* / ts.* bridges are not registered; BlockConfig::sql_path / kv_path / ts_path are accepted but ignored (fields retained for API stability).
• mcp-http: mcp.connect_http returns an explicit error when called.

Sandbox

sandbox installs an optional process-wide execution boundary (Landlock + seccomp, Linux only): filesystem writes are confined to an allowlist and io_uring is denied, while reads and executes stay open. It is inherited by sh.exec / mcp.connect children, and must be applied before any async runtime spawns worker threads — see the module docs.

Re-exports

pub use host::run;

pub use host::BlockConfig;

pub use host::BlockConfigBuilder;

pub use host::HostContext;

Modules

bridge

Lua Stdlib Bridge — injects all *.* global APIs into the Lua VM.

bus

EventBus: serial event dispatcher feeding Lua handlers registered via bus.on(kind, fn) / bus.on_any(fn).

host

Host — the thin Rust shell that wires up Lua VM, Mesh, HTTP, and MCP.

sandbox

Sandbox — a generic, process-wide execution boundary (Linux only).