Zerion MCP Server

## ADDED Requirements ### Requirement: Configuration File Support The system SHALL support loading configuration from YAML files. #### Scenario: Load from config file - **WHEN** config.yaml exists in current directory - **THEN** configuration is loaded from file - **AND** all settings are validated - **AND** missing required fields raise ConfigError #### Scenario: Default config path - **WHEN** no config file path is specified - **THEN** system checks for config.yaml in current directory - **AND** falls back to hardcoded defaults if not found #### Scenario: Custom config path - **WHEN** CONFIG_PATH environment variable is set - **THEN** configuration is loaded from specified path - **AND** error is raised if file does not exist ### Requirement: Environment Variable Overrides The system SHALL allow environment variables to override config file values. #### Scenario: Override API key - **WHEN** ZERION_API_KEY environment variable is set - **THEN** it overrides api_key from config file - **AND** takes precedence over all other sources #### Scenario: Override base URL - **WHEN** ZERION_BASE_URL environment variable is set - **THEN** it overrides base_url from config file - **AND** is used for HTTP client initialization ### Requirement: Configuration Validation The system SHALL validate all configuration values on load. #### Scenario: Valid configuration - **WHEN** configuration is loaded - **THEN** required fields (api_key, base_url) are present - **AND** URLs are properly formatted - **AND** no validation errors are raised #### Scenario: Invalid configuration - **WHEN** required field is missing - **THEN** ConfigError is raised - **AND** error message specifies which field is missing - **AND** server does not start ### Requirement: Configuration Schema The system SHALL support the following configuration structure: ```yaml name: "Zerion API" base_url: "https://api.zerion.io" oas_url: "https://raw.githubusercontent.com/smart-mcp-proxy/zerion-mcp-server/main/zerion_mcp_server/openapi_zerion.yaml" api_key: "${ZERION_API_KEY}" # Environment variable substitution logging: level: "INFO" format: "json" ``` #### Scenario: Full config parsing - **WHEN** complete config.yaml is loaded - **THEN** all fields are accessible via ConfigManager - **AND** environment variable substitution is performed - **AND** nested objects (logging) are properly parsed