arazzo-runner 0.9.6

Execution libraries and test tools for Arazzo workflows and Open API operations

Arazzo Runner [Beta]

The Arazzo Runner is a workflow execution engine that processes and executes API workflows defined in the Arazzo format and individual API calls defined in OpenAPI specifications.

Usage

Execute a Workflow

from arazzo_runner import ArazzoRunner

runner = ArazzoRunner.from_arazzo_path("../../workflows/discord.com/workflows.arazzo.json")

result = runner.execute_workflow("workflowId", {"param1": "value1"})

Display Authentication Options

from arazzo_runner import ArazzoRunner

runner = ArazzoRunner.from_arazzo_path("../../workflows/discord.com/workflows.arazzo.json")

print(runner.get_env_mappings())

Execute a Single OpenAPI Operation

from arazzo_runner import ArazzoRunner
# Execute a single OpenAPI operation with an operationId
result = runner.execute_operation("operationId", {"param1": "value1"})

# Execute a single OpenAPI operation by path
result = runner.execute_operation("GET /users/@me/guilds", {"param1": "value1"})

Create a Runner with a Custom Base Path

# Create a runner instance with a custom base path for resolving OpenAPI file paths
runner_with_base_path = ArazzoRunner.from_arazzo_path(
    "./my/arazzo.yaml", 
    base_path="./my/source/description/base"
)

Authentication

Credentials are resolved from environment variables defined by the Arazzo Runner based on the Arazzo or OpenAPI file. You can see the authentication options by using runner.get_env_mappings or the show-env-mappings command line tool defined below.

The Arazzo Runner supports various authentication methods defined in OpenAPI specifications:

• API Key: Header, Query, or Cookie API keys
• OAuth2: Some OAuth2 Flows (Client Credentials, Password)
• HTTP: Basic and Bearer Authentication

Auth Methods Not Yet Supported

• OAuth2: Authorization Code, Implicit
• OpenID: OpenID Connect
• Custom: Custom Authentication Schemes

Command Line Usage

Usage:

uvx arazzo-runner <command> [command-specific arguments] [global options]

Commands:

1. show-env-mappings: Show environment variable mappings for authentication based on an Arazzo or OpenAPI file.

   uvx arazzo-runner show-env-mappings [arazzo_path | --openapi-path PATH]
   

   • arazzo_path: Path to the Arazzo YAML file (use this OR --openapi-path).
   • --openapi-path PATH: Path to the OpenAPI spec file (use this OR arazzo_path). One of the path arguments is required.

2. execute-workflow: Execute a workflow defined in an Arazzo file.

   uvx arazzo-runner execute-workflow <arazzo_path> --workflow-id <workflow_id> [--inputs <json_string>]
   

   • arazzo_path: Required. Path to the Arazzo YAML file containing the workflow.
   • --workflow-id WORKFLOW_ID: Required. ID of the workflow to execute.
   • --inputs INPUTS: Optional JSON string of workflow inputs (default: {}).

3. execute-operation: Execute a single API operation directly from an OpenAPI specification (or an Arazzo file for context).

   uvx arazzo-runner execute-operation [--arazzo-path PATH | --openapi-path PATH] [--operation-id ID | --operation-path PATH_METHOD] [--inputs <json_string>]
   

   • --arazzo-path PATH: Path to an Arazzo file (provides context, use this OR --openapi-path).
   • --openapi-path PATH: Path to the OpenAPI spec file (use this OR --arazzo-path). One of the path arguments is required.
   • --operation-id ID: The operationId from the OpenAPI spec (use this OR --operation-path).
   • --operation-path PATH_METHOD: The HTTP method and path (e.g., 'GET /users/{id}') from the OpenAPI spec (use this OR --operation-id). One of the operation identifiers is required.
   • --inputs INPUTS: Optional JSON string of operation inputs (parameters, request body) (default: {}).

4. list-workflows: List all available workflows defined in an Arazzo file.

   uvx arazzo-runner list-workflows <arazzo_path>
   

   • arazzo_path: Required. Path to the Arazzo YAML file.

5. describe-workflow: Show details of a specific workflow, including its summary, inputs, steps, and outputs.

   uvx arazzo-runner describe-workflow <arazzo_path> --workflow-id <workflow_id>
   

   • arazzo_path: Required. Path to the Arazzo YAML file containing the workflow.
   • --workflow-id WORKFLOW_ID: Required. ID of the workflow to describe.

6. generate-example: Generate an example CLI command to execute a specified workflow, including placeholder inputs.

   uvx arazzo-runner generate-example <arazzo_path> --workflow-id <workflow_id>
   

   • arazzo_path: Required. Path to the Arazzo YAML file containing the workflow.
   • --workflow-id WORKFLOW_ID: Required. ID of the workflow to generate an example for.

Global Options:

• --log-level {DEBUG,INFO,WARNING,ERROR,CRITICAL}: Set the logging level (default: INFO).

Examples:

# Show environment variable mappings using an Arazzo file
uvx arazzo-runner show-env-mappings ./tests/fixtures/discord/discord.arazzo.yaml

# Show environment variable mappings using an OpenAPI file
uvx arazzo-runner show-env-mappings --openapi-path ./tests/fixtures/discord/discord.openapi.json

# Execute a workflow
uvx arazzo-runner execute-workflow ./tests/fixtures/discord/discord.arazzo.yaml --workflow-id getUserInfoAndSendMessage --inputs '{"recipient_id": "1234567890", "message_content": "Hello!"}'

# Execute a specific operation using its operationId and an OpenAPI file
uvx arazzo-runner execute-operation --openapi-path ./tests/fixtures/discord/discord.openapi.json --operation-id list_my_guilds --inputs '{}'

# Execute a specific operation using its path/method and an Arazzo file (for context)
uvx arazzo-runner execute-operation --arazzo-path ./tests/fixtures/discord/discord.arazzo.yaml --operation-path 'GET /users/@me/guilds' --inputs '{}' --log-level DEBUG

# List all available workflows
uvx arazzo-runner list-workflows ./tests/fixtures/discord/discord.arazzo.yaml

# Describe a specific workflow
uvx arazzo-runner describe-workflow ./tests/fixtures/discord/discord.arazzo.yaml --workflow-id getUserInfoAndSendMessage

# Generate an example CLI command to execute a workflow
uvx arazzo-runner generate-example ./tests/fixtures/discord/discord.arazzo.yaml --workflow-id getUserInfoAndSendMessage

Help:

# General help
uvx arazzo-runner --help

# Help for a specific command (e.g., execute-operation)
uvx arazzo-runner execute-operation --help

Server URL Configuration

Arazzo Runner supports dynamic server URLs as defined in the servers object of an OpenAPI specification. This allows you to define API server URLs with templated variables (e.g., https://{instance_id}.api.example.com/v1 or https://api.example.com/{region}/users).

Variable Resolution

When an operation requires a server URL with variables, Arazzo Runner resolves these variables in the following order of precedence:

1. Runtime Parameters: Values passed explicitly when executing an operation or workflow (e.g., via the --server-variables CLI argument or the runtime_params parameter in execute_operation/execute_workflow methods). These parameters should be provided as a dictionary where keys match the expected environment variable names for the server variables (see below).
2. Environment Variables: If not provided as a runtime parameter, Arazzo Runner attempts to find an environment variable.
3. Default Values: If not found in runtime parameters or environment variables, the default value specified for the variable in the OpenAPI document's servers object is used.

If a variable in the URL template cannot be resolved through any of these means, and it does not have a default value, an error will occur.

Environment Variable Naming

The environment variables for server URLs follow these naming conventions:

• If the OpenAPI specification's info.title is available and an API_TITLE_PREFIX can be derived from it (typically the first word of the title, uppercased and sanitized, e.g., PETSTORE from "Petstore API"), the format is: [API_TITLE_PREFIX_]RUNNER_SERVER_<VAR_NAME_UPPERCASE> Example: PETSTORE_RUNNER_SERVER_REGION=us-east-1

• If an API_TITLE_PREFIX cannot be derived (e.g., info.title is missing or empty), the format is: RUNNER_SERVER_<VAR_NAME_UPPERCASE> Example: RUNNER_SERVER_INSTANCE_ID=my-instance-123

The <VAR_NAME_UPPERCASE> corresponds to the variable name defined in the servers object's variables map (e.g., region or instance_id), converted to uppercase.

You can use the show-env-mappings CLI command to see the expected environment variable names for server URLs, alongside authentication variables, for a given OpenAPI specification.

Example

Consider an OpenAPI specification with:

• info.title: "My Custom API"
• A server definition:

  servers:
    - url: "https://{instance}.api.example.com/{version}"
      variables:
        instance:
          default: "prod"
          description: "The API instance name."
        version:
          default: "v1"
          description: "API version."
  

To set the instance to "dev" and version to "v2" via environment variables, you would set:

export MYCUSTOM_RUNNER_SERVER_INSTANCE=dev
export MYCUSTOM_RUNNER_SERVER_VERSION=v2

(Assuming "MYCUSTOM" is derived from "My Custom API").

Alternatively, to provide these at runtime via the CLI when executing an operation:

uvx arazzo-runner execute-operation --openapi-path path/to/spec.yaml --operation-id someOperation \
  --server-variables '{"MYCUSTOM_RUNNER_SERVER_INSTANCE": "staging", "MYCUSTOM_RUNNER_SERVER_VERSION": "v2beta"}'

Blob Storage

Arazzo Runner supports blob storage for handling large binary responses without putting the raw binary into LLM context windows. This feature is disabled by default and must be explicitly enabled.

Enabling Blob Storage

Instantiate either LocalFileBlobStore (persists to disk) or InMemoryBlobStore (ephemeral) and pass it to ArazzoRunner:

from arazzo_runner import ArazzoRunner, LocalFileBlobStore

blob_store = LocalFileBlobStore()  # Or InMemoryBlobStore() for testing

runner = ArazzoRunner.from_arazzo_path("workflow.yaml", blob_store=blob_store)
result = runner.execute_workflow("download-file", {"url": "https://example.com/large-file.pdf"})

Blob storage is disabled when blob_store is omitted or None (the default).

Configuration

You can configure the blob storage threshold and directory via environment variables:

• ARAZZO_BLOB_THRESHOLD: Size threshold in bytes for storing as blob (default: 32768)
• BLOB_STORE_PATH: Directory for blob storage (default: ./blobs)

State Management: Blob storage introduces additional state that must be managed:

• Blob files are stored on disk and referenced by unique IDs
• State persists between workflow executions

Development

All following sections assume that you're inside the ./runner directory of the arazzo-engine monorepo.

Prerequisites

Python 3.11 or higher is required. You can check your Python version with:

python --version

Installation

1. Install PDM if you haven't already:

   # Install PDM
   curl -sSL https://pdm.fming.dev/install-pdm.py | python3 -
   
   # Or with Homebrew (macOS/Linux)
   brew install pdm
   
   # Or with pip
   pip install pdm
   

2. Install project dependencies:

   # Install dependencies
   pdm install
   pdm install --plugins
   

Executing Runner CLI commands

You can run the Arazzo Runner CLI commands using python's -m flag:

python -m arazzo_runner --help

This will display the help message for the Arazzo Runner CLI with all available commands.

Running Tests

The Arazzo Runner includes a comprehensive testing framework for workflow validation:

• Automated test fixtures for different workflow scenarios
• Mock HTTP responses based on OpenAPI specs
• Custom mock responses for specific endpoints
• Validation of workflow outputs and API call counts

For details on testing, see Arazzo Runner Testing Framework

# Run all tests
pdm run test

# Run making actual API calls
pdm run test-real 

# Run a specific test file
pdm run test tests/test_arazzo_runner.py

Code Formatting & Linting

The project uses black, isort and ruff for code formatting.

# Check formatting & linting without making changes
pdm run lint

# Format & lint code 
pdm run lint:fix

Available PDM Scripts

• pdm run test - Run all tests
• pdm run test - Run all tests making actual API calls
• pdm run lint - Check formatting & linting without making changes
• pdm run lint:fix - Format & lint code

Overview

Arazzo Runner orchestrates API workflows by:

• Loading and validating Arazzo workflow documents
• Executing workflow steps sequentially or conditionally
• Evaluating runtime expressions and success criteria
• Extracting and transforming data between steps
• Handling flow control (continue, goto, retry, end)
• Supporting nested workflow execution
• Providing event callbacks for workflow lifecycle events
• Managing authentication requirements across different APIs

Arazzo Format

The Arazzo specification is our workflow definition format that orchestrates API calls using OpenAPI specifications.

• Schema: arazzo-schema.yaml
• Documentation: arazzo-spec.md