Bicep RPC Client for Python

An independent Python client for programmatically interacting with the Bicep CLI over JSON-RPC.

Getting started

Install the package

python -m pip install anthonycmartin-bicep-rpc-client==0.1.5

The distribution is named anthonycmartin-bicep-rpc-client; import its public API from anthonycmartin.bicep_rpc_client.

Initialize the client

BicepClientFactory.initialize() downloads and caches the requested Bicep CLI version, starts bicep jsonrpc --stdio, and returns a client. Use the client as a context manager so the Bicep process is always terminated.

from anthonycmartin.bicep_rpc_client import BicepClientFactory

with BicepClientFactory().initialize() as client:
    print(f"Bicep CLI version: {client.get_version()}")

With no configuration, the factory resolves and caches the latest Bicep CLI under ~/.bicep/bin.

Pin a specific Bicep version

Set bicep_version without a leading v. Versioned CLIs are cached separately.

from anthonycmartin.bicep_rpc_client import BicepClientConfiguration, BicepClientFactory

client = BicepClientFactory().initialize(
    BicepClientConfiguration(bicep_version="0.46.1")
)

Use an existing Bicep installation

Set existing_cli_path to skip downloading the CLI. This takes precedence over bicep_version and cache_root.

client = BicepClientFactory().initialize(
    BicepClientConfiguration(existing_cli_path="/usr/local/bin/bicep")
)

Use a custom cache directory

client = BicepClientFactory().initialize(
    BicepClientConfiguration(
        bicep_version="0.46.1",
        cache_root="/var/cache/bicep",
    )
)

BicepClientConfiguration accepts bicep_version, existing_cli_path, and cache_root; every field is optional and paths may be strings or pathlib.Path values.

Available operations

All operations communicate synchronously with one Bicep CLI process. Relative request paths are resolved to absolute paths before they are sent. Bicep compilation failures are returned in typed response diagnostics; transport failures raise standard Python exceptions and JSON-RPC failures raise RpcError.

compile

compile() compiles a .bicep file into an ARM template JSON string.

from anthonycmartin.bicep_rpc_client import CompileRequest

result = client.compile(CompileRequest("./main.bicep"))
if result.success:
    print(result.contents)
else:
    print(result.diagnostics)

CompileRequest contains path. CompileResponse contains success, diagnostics, and contents; contents is None when the CLI does not return compiled output.

compile_params

compile_params() compiles a .bicepparam file into ARM deployment parameters and accepts JSON-serializable parameter overrides.

from anthonycmartin.bicep_rpc_client import CompileParamsRequest

result = client.compile_params(
    CompileParamsRequest(
        "./main.bicepparam",
        parameter_overrides={
            "environment": "test",
            "instanceCount": 2,
        },
    )
)
if result.success:
    print(result.parameters)
    print(result.template)
    print(result.template_spec_id)

CompileParamsRequest contains path and parameter_overrides. CompileParamsResponse contains success, diagnostics, parameters, template, and template_spec_id. The three content fields may be None; template_spec_id is populated when the parameters file references a template spec.

format

format() applies the standard Bicep formatter and returns the formatted source. It requires Bicep CLI 0.37.1 or later and does not write the file.

from pathlib import Path

from anthonycmartin.bicep_rpc_client import FormatRequest

result = client.format(FormatRequest("./main.bicep"))
Path("./main.bicep").write_text(result.contents, encoding="utf-8")

FormatRequest contains path. FormatResponse contains contents.

get_metadata

get_metadata() returns the parameters, outputs, exports, and file-level metadata declared by a Bicep file.

from anthonycmartin.bicep_rpc_client import GetMetadataRequest

result = client.get_metadata(GetMetadataRequest("./main.bicep"))
for parameter in result.parameters:
    print(f"parameter {parameter['name']}")
for output in result.outputs:
    print(f"output {output['name']}")
for exported in result.exports:
    print(f"export {exported['name']}")
for item in result.metadata:
    print(f"metadata {item['name']}")

GetMetadataRequest contains path. GetMetadataResponse exposes parameters, outputs, exports, and metadata as tuples of JSON-shaped dictionaries so fields added by future Bicep versions remain available.

get_file_references

get_file_references() returns every file referenced by a Bicep file, including modules, loaded files, and the entry point.

from anthonycmartin.bicep_rpc_client import GetFileReferencesRequest

result = client.get_file_references(GetFileReferencesRequest("./main.bicep"))
for file_path in result.file_paths:
    print(file_path)

GetFileReferencesRequest contains path. GetFileReferencesResponse contains the file_paths tuple.

get_deployment_graph

get_deployment_graph() returns resource nodes and dependency edges for visualization or graph analysis.

from anthonycmartin.bicep_rpc_client import GetDeploymentGraphRequest

result = client.get_deployment_graph(GetDeploymentGraphRequest("./main.bicep"))
for node in result.nodes:
    print(f"node {node['name']} ({node['type']})")
for edge in result.edges:
    print(f"{edge['source']} -> {edge['target']}")

GetDeploymentGraphRequest contains path. GetDeploymentGraphResponse exposes nodes and edges as tuples of JSON-shaped dictionaries.

get_snapshot

get_snapshot() evaluates a .bicepparam file using an Azure deployment context and returns a serialized deployment snapshot. It requires Bicep CLI 0.36.1 or later but does not deploy resources or require Azure credentials.

from anthonycmartin.bicep_rpc_client import (
    GetSnapshotRequest,
    SnapshotExternalInput,
    SnapshotMetadata,
)

with BicepClientFactory().initialize(
    BicepClientConfiguration(bicep_version="0.46.1")
) as client:
    result = client.get_snapshot(
        GetSnapshotRequest(
            "./main.bicepparam",
            metadata=SnapshotMetadata(
                tenant_id="ddbe463a-0554-485d-b589-0b17d60cd38b",
                subscription_id="28c9069e-23e8-47d2-b640-00d2e0f09616",
                resource_group="my-resource-group",
                location="eastus",
                deployment_name="my-deployment",
            ),
            external_inputs=(
                SnapshotExternalInput(
                    kind="sys.envVar",
                    config="BUILD_ID",
                    value="1234",
                ),
            ),
        )
    )
    print(result.snapshot)

SnapshotMetadata accepts optional tenant_id, subscription_id, resource_group, location, and deployment_name values. SnapshotExternalInput contains kind, value, and optional config. GetSnapshotRequest contains path, metadata, and the external_inputs tuple. GetSnapshotResponse contains the JSON snapshot in snapshot.

get_version

get_version() returns the connected Bicep CLI version. The first result is cached for the lifetime of the client.

version = client.get_version()
print(version)

Client lifecycle

BicepClient owns the Bicep subprocess. Prefer a with block, or call close() explicitly. close() first asks the process to terminate, waits up to five seconds, and then kills it if necessary. Calling close() after the process exits has no effect.

client = BicepClientFactory().initialize(
    BicepClientConfiguration(bicep_version="0.46.1")
)
try:
    result = client.compile(CompileRequest("./main.bicep"))
finally:
    client.close()

BicepClient(executable) is also public for callers that already own Bicep installation and want to start the process directly. BicepClientFactory.initialize() is preferred because it locates or installs the CLI and verifies that the process responds to get_version() before returning.

Error handling

JSON-RPC server errors raise RpcError, a RuntimeError subclass with code, message, and data attributes.

from anthonycmartin.bicep_rpc_client import RpcError

try:
    result = client.compile(CompileRequest("./main.bicep"))
except RpcError as error:
    print(f"Bicep RPC error {error.code}: {error.message}")
    print(error.data)

Unsupported operation versions raise RuntimeError. A closed JSON-RPC output stream raises EOFError; download, process, serialization, and file errors retain their standard Python exception types.

Automatic downloads support Windows, Linux, and macOS on x64 and Arm64.

Public API summary

All request, response, metadata, external-input, and configuration models are immutable slotted dataclasses.

This package is independent and non-official. Its API may change between releases.