# API Reference
This reference provides an entry to the OpenRath v2.0.0 API and documents the
retained v1-compatible Python façade by its package structure. Each page
contains three kinds of information:

| Information | Purpose |
| --- | --- |
| Source | Corresponding source files for jumping back to the implementation. |
| Public contract | Common signatures, parameters, return values, and exceptions. |
| Autodoc | Class/function documentation imported from the current source. |

## OpenRath v2.0.0

| Reference | Contents |
| --- | --- |
| [v2.0.0 API reference](../v2/api-reference.md) | Definition, context, runtime, governed adapters, artifacts, deployment, evaluation, observability, events/errors, Agent Server, and clients. |

## v1-compatible package structure

| Package | Contents |
| --- | --- |
| [`rath`](rath.md) | Package-level entrypoint. |
| [`rath.session`](session.md) | `Session`, Provider/sandbox placement, chunks, loop, selection, compression, persistence, lineage. |
| [`rath.backend`](backend.md) | Backend abstractions, sandboxes, persistent sandbox identities, tool payloads, results, registry, stream. |
| [`rath.flow`](flow.md) | Module tree, `AgentParam`, presets, `Selector`, and static `CompiledWorkflow` manifests. |
| [`rath.flow.tool`](flow_tool.md) | `FlowToolCall`, built-in system tools, MCP adapters, backend tool factories, schema merging. |
| [`rath.llm`](llm.md) | `Provider`, request/response types, OpenAI, Anthropic, and optional LiteLLM clients, registry, streaming. |
| [`rath.memory`](memory.md) | Memory backends, stores, op payloads, result types, local backend, OpenViking adapter boundary, registry. |
| [`rath.config`](config.md) | Split config/credentials, backend presets, EnvSpec registry, and store helpers. |
| [`rath.persistence`](persistence.md) | Atomic writes, root layout manifest, and cross-plane GC. |
| [`rath.utils`](utils.md) | Project-root and test environment helpers. |

```{toctree}
---
maxdepth: 2
caption: API Reference
---

rath
session
backend
flow
flow_tool
llm
memory
config
persistence
utils
```