Environment Variable Specifications
Environment variable specifications define configuration values required by MCP servers and skills.
Overview​
Environment variables provide API keys, authentication tokens, and configuration values to agents. Each specification defines the variable's purpose, where to obtain it, and metadata.
Required Fields​
id (string)​
Unique identifier (UPPER_SNAKE_CASE, e.g., KAGGLE_TOKEN, GITHUB_TOKEN, OPENAI_API_KEY)
Important: Unlike other specs, envvar IDs use UPPER_SNAKE_CASE to match environment variable naming conventions.
name (string)​
Display name shown in the UI
description (string)​
Purpose and usage description
Optional Fields​
registrationUrl (string)​
URL where users can obtain the variable (e.g., API key registration page)
registrationUrl: https://www.kaggle.com/settings/account
registrationUrl: https://github.com/settings/tokens
registrationUrl: https://platform.openai.com/api-keys
tags (list of strings)​
Categorization tags
tags:
- authentication
- api-key
- kaggle
- data
icon (string)​
UI icon identifier
emoji (string)​
UI emoji identifier
Complete Example​
# Copyright (c) 2025-2026 Datalayer, Inc.
# Distributed under the terms of the Modified BSD License.
id: KAGGLE_TOKEN
name: Kaggle API Token
description: >
API token for accessing Kaggle datasets, competitions, notebooks, and models.
Required for Kaggle MCP server authentication.
registrationUrl: https://www.kaggle.com/settings/account
tags:
- authentication
- api-key
- kaggle
- data
Environment Variable Hierarchy​
Environment Variable Specification
├── Basic Info (id, name, description)
├── Registration (registrationUrl)
├── Categorization (tags)
└── UI (icon, emoji)
Linking to MCP Servers and Skills​
Environment variables are referenced by their ID in MCP server and skill specifications:
In MCP Server Spec​
id: kaggle
name: Kaggle MCP Server
# ... other fields ...
envvars:
- KAGGLE_TOKEN
args:
- "--Authorization"
- "Bearer ${KAGGLE_TOKEN}"
In Skill Spec​
id: data-analysis
name: Data Analysis Skill
# ... other fields ...
envvars:
- OPENAI_API_KEY
optional_env_vars:
- PLOT_DPI
- CHART_THEME
Available Environment Variables​
The following environment variables are defined in agentspecs/envvars/:
KAGGLE_TOKEN- Kaggle API authenticationGITHUB_TOKEN- GitHub authentication for MCP server and skillsTAVILY_API_KEY- Tavily search and web crawlingALPHAVANTAGE_API_KEY- Alpha Vantage financial dataOPENAI_API_KEY- OpenAI API accessSLACK_BOT_TOKEN- Slack bot authenticationSLACK_TEAM_ID- Slack workspace identifierSLACK_CHANNEL_IDS- Slack channel access listGOOGLE_OAUTH_CLIENT_ID- Google Workspace OAuth client IDGOOGLE_OAUTH_CLIENT_SECRET- Google Workspace OAuth secret
Best Practices​
- ID Format: Use UPPER_SNAKE_CASE (
KAGGLE_TOKEN, notkaggle_tokenorKaggleToken) - Naming: Follow standard environment variable conventions
- Description: Explain what the variable is used for and which services require it
- Registration URL: Always provide when applicable to help users obtain the value
- Tags: Include service name, type (api-key, token, secret), and category
- Security: Never include actual values in the specification
- Documentation: Be clear about whether the variable is required or optional
- Scope: Define one variable per specification file