OAK Runner [Beta]

The OAK 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 oak_runner import OAKRunner

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

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

Display Authentication Options

from oak_runner import OAKRunner

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

print(runner.get_env_mappings())

Execute a Single OpenAPI Operation

from oak_runner import OAKRunner
# 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 = OAKRunner.from_arazzo_path(
    "./my/arazzo.yaml", 
    base_path="./my/source/description/base"
)

Authentication

Credentials are resolved from environment variables defined by the OAK 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 OAK 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 oak-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 oak-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 oak-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 oak-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 oak-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 oak-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 oak-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 oak-runner show-env-mappings ./tests/fixtures/discord/discord.arazzo.yaml

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

# Execute a workflow
uvx oak-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 oak-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 oak-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 oak-runner list-workflows ./tests/fixtures/discord/discord.arazzo.yaml

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

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

Help:

# General help
uvx oak-runner --help

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

Server URL Configuration

OAK 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, OAK 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, OAK 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_]OAK_SERVER_<VAR_NAME_UPPERCASE> Example: PETSTORE_OAK_SERVER_REGION=us-east-1

• If an API_TITLE_PREFIX cannot be derived (e.g., info.title is missing or empty), the format is: OAK_SERVER_<VAR_NAME_UPPERCASE> Example: OAK_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_OAK_SERVER_INSTANCE=dev
export MYCUSTOM_OAK_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 oak-runner execute-operation --openapi-path path/to/spec.yaml --operation-id someOperation \
  --server-variables '{"MYCUSTOM_OAK_SERVER_INSTANCE": "staging", "MYCUSTOM_OAK_SERVER_VERSION": "v2beta"}'

Overview

OAK 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

Testing

The OAK 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 OAK Runner Testing Framework

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