Crate harn_vm 

Re-exports

pub use checkpoint::register_checkpoint_builtins;

pub use llm::register_llm_builtins;

pub use mcp::connect_mcp_server;

pub use mcp::connect_mcp_server_from_json;

pub use mcp::connect_mcp_server_from_spec;

pub use mcp::register_mcp_builtins;

pub use mcp_server::take_mcp_serve_prompts;

pub use mcp_server::take_mcp_serve_registry;

pub use mcp_server::take_mcp_serve_resource_templates;

pub use mcp_server::take_mcp_serve_resources;

pub use mcp_server::tool_registry_to_mcp_tools;

pub use mcp_server::McpServer;

pub use metadata::register_metadata_builtins;

pub use metadata::register_scan_builtins;

pub use stdlib::register_agent_stdlib;

pub use stdlib::register_core_stdlib;

pub use stdlib::register_io_stdlib;

pub use stdlib::register_vm_stdlib;

pub use store::register_store_builtins;

pub use value::*;

Modules

agent_events

Agent event stream — the ACP-aligned observation surface for the agent loop.

bridge

JSON-RPC 2.0 bridge for host communication.

checkpoint

Checkpoint system for resilient pipeline execution.

events

Structured event emission for observability.

iter

Lazy iterator protocol for the Harn VM.

jsonrpc

Shared JSON-RPC 2.0 message construction helpers.

llm

LLM integration: API calls, streaming, agent loops, tool handling, and tracing.

llm_config

mcp

MCP (Model Context Protocol) client for connecting to external tool servers.

mcp_server

MCP server mode: expose Harn tools, resources, resource templates, and prompts as MCP capabilities over stdio.

metadata

Project metadata store for Harn’s runtime state root.

orchestration

runtime_paths

schema

stdlib

Standard library builtins for the Harn VM.

stdlib_modules

store

Persistent key-value store backed by Harn’s runtime state root.

tool_annotations

Tool annotations — the single source of truth for tool semantics.

tracing

Pipeline Observability: structured tracing spans with parent/child relationships.

value

visible_text

Structs

Chunk

A compiled chunk of bytecode.

CompileError

Compile error.

CompiledFunction

A compiled function (closure body).

Compiler

Compiles an AST into bytecode.

DebugState

Information about current execution state for the debugger.

Vm

The Harn bytecode virtual machine.

Enums

Constant

A constant value in the constant pool.

DebugAction

Debug action returned by the debug hook.

Op

Bytecode opcodes for the Harn VM.

Functions

clone_async_builtin_child_vm

Clone the VM at the top of the async-builtin child VM stack, returning a fresh Vm instance that callers own and can use without coordinating with other concurrent users of the stack. This replaces the legacy take/restore pattern: that pattern serialized access because only one consumer could hold the single stack entry at a time, which prevented any form of concurrent tool-handler execution within a single agent_loop iteration. Cloning is cheap — the VM struct shares its heavy state (env, builtins, bridge, module_cache) via Arc/Rc — so multiple concurrent handlers can each have their own execution context.

compile_source

Lex, parse, type-check, and compile source to bytecode in one call. Bails on the first type error. For callers that need diagnostics rather than early exit, use harn_parser::check_source directly and then call Compiler::new().compile(&program).

register_http_builtins

Register HTTP builtins on a VM.

reset_http_state

Reset thread-local HTTP mock state. Call between test runs.

reset_thread_local_state

Reset all thread-local state that can leak between test runs. Call this before each test execution for proper isolation.

restore_async_builtin_child_vmDeprecated

Legacy API — now a no-op because take_async_builtin_child_vm returns a clone rather than popping the stack, so there is nothing to restore. Kept for backward compatibility.

take_async_builtin_child_vmDeprecated

Legacy API preserved for backward compatibility with any out-of-tree callers. New code should use clone_async_builtin_child_vm() instead — take serializes concurrent callers because only one can hold the popped value at a time. Internally this now delegates to a clone so even legacy callers don’t deadlock each other, but the name is kept until external callers migrate.