#moonrockz/smithy-codegen-python

A Smithy code generator for Python JSON-RPC 2.0 peers. Register it in the build runner as python-jsonrpc-codegen. One run generates one peer of a protocol.

{
  "version": "1.0",
  "plugins": {
    "python-jsonrpc-codegen::python-terminal": {
      "service": "example.payments#PaymentTerminal",
      "protocol": "example.payments#TerminalProtocol",
      "peer": "terminal",
      "package": "payment_terminal",
      "integrations": ["fastapi"]
    }
  }
}

#Settings

service, protocol, peer and transports: the shared settings of the JSON-RPC plugins (PeerSettings in moonrockz/smithy-codegen-jsonrpc).
package (required): the Python package name of the output, such as payment_terminal.
integrations (optional): ["fastapi"] adds FastAPI and uvicorn to the dependencies.

#Output

File	Content
pyproject.toml	The project, with exact versions of the dependencies and the checks (pyright strict, ruff, pytest).
<package>/models.py	A frozen Pydantic v2 model for each structure, a model for each union member and a tagged type alias for each union, a StrEnum or IntEnum for each enum. Fields are snake_case; the wire names are the aliases.
<package>/errors.py	For each modeled error: a data model <Name>Data and an exception <Name> with to_rpc_error() and from_data(data).
<package>/handler.py	A Protocol with one method for each method that the peer accepts, and register_<service>(peer, handler). The cancel method has no handler: the runtime cancels the call.
<package>/client.py	A typed client of the service that the peer calls. Each call has checked: bool = True.
<package>/session.py	session_rules() from the prepared session contract, and new_peer(log=None).
<package>/_runtime/	A copy of runtimes/python/smithy_jsonrpc_runtime.
tests/test_generated.py	A check of the session rules, the peer and one model.

Exact values: a bigDecimal is a Decimal (BigDecimal), an integer of any size is an int (BigInteger), a blob is bytes (base64 on the wire). A number never goes through float.

The generator does not interpret the RPC traits again. It renders the prepared contracts of moonrockz/smithy-validation/rpc, so the generated peers and smithy validate rpc transcript agree.

mise run runtime:embed copies the runtime into runtime_files.mbt. mise run validate checks that the copy is current.

class_name

source

fn class_name(name : String) -> String

The name of a generated class: the contextual name with an upper-case first letter. A name that the generated modules use gets a _ suffix.

enum_member_name

source

fn enum_member_name(name : String) -> String

An UPPER_SNAKE name for an enum member. insertCard is INSERT_CARD and USD stays USD.

method_name

source

fn method_name(name : String) -> String

The name of a handler or client method: a snake_case name. The client keeps its peer in attribute peer, so a method peer gets a _ suffix.

pascal_name

source

fn pascal_name(name : String) -> String

A PascalCase part of a class name, such as the member part of a union member class. manualEntry is ManualEntry.

plugin

source

fn plugin(model : @moonrockz/smithy.Model
Model, settings : Json) -> Map[String, String] raise @moonrockz/smithy-build.BuildError
BuildError

The plugin for the build runner. Register it as python-jsonrpc-codegen.

py_string

source

fn py_string(text : String) -> String

The text of a Python string literal in double quotes.

run

source

fn run(plugin : @moonrockz/smithy-codegen.PluginContext
PluginContext) -> Map[String, String] raise @moonrockz/smithy-codegen.CodegenError
CodegenError

Generate a Python JSON-RPC peer. Settings: service, protocol, peer, transports (see PeerSettings), package, the Python package name of the output, such as payment_terminal, and integrations (optional), such as ["fastapi"].

snake_name

source

fn snake_name(name : String) -> String

A snake_case name for a field, a method or a function. A keyword or a model attribute gets a _ suffix. A name that starts with a digit gets an n prefix.