Configuration¶

All configuration is done through environment variables.

Required Variables¶

Variable	Description
`DATAHUB_URL`	DataHub GMS URL (e.g., `https://datahub.company.com`)
`DATAHUB_TOKEN`	Personal access token from DataHub

Optional Variables¶

Variable	Description	Default
`DATAHUB_TIMEOUT`	Request timeout in seconds	`30`
`DATAHUB_RETRY_MAX`	Maximum retry attempts	`3`
`DATAHUB_DEFAULT_LIMIT`	Default search result limit	`10`
`DATAHUB_MAX_LIMIT`	Maximum allowed limit	`100`
`DATAHUB_MAX_LINEAGE_DEPTH`	Maximum lineage traversal depth	`5`
`DATAHUB_CONNECTION_NAME`	Display name for primary connection	`datahub`
`DATAHUB_ADDITIONAL_SERVERS`	JSON map of additional servers	(empty)
`DATAHUB_WRITE_ENABLED`	Enable write operations (`true` or `1`)	`false`
`DATAHUB_DEBUG`	Enable debug logging (`1` or `true`)	`false`

Extensions Variables¶

Optional middleware can be enabled via environment variables:

Variable	Description	Default
`MCP_DATAHUB_EXT_LOGGING`	Enable structured logging of tool calls	`false`
`MCP_DATAHUB_EXT_METRICS`	Enable metrics collection	`false`
`MCP_DATAHUB_EXT_METADATA`	Enable metadata enrichment on results	`false`
`MCP_DATAHUB_EXT_ERRORS`	Enable error hint enrichment	`true`

Example Configuration¶

# Required
export DATAHUB_URL=https://datahub.company.com
export DATAHUB_TOKEN=your_personal_access_token

# Optional tuning
export DATAHUB_TIMEOUT=60
export DATAHUB_DEFAULT_LIMIT=20
export DATAHUB_MAX_LIMIT=50

# Debug logging (for troubleshooting)
export DATAHUB_DEBUG=1

Multi-Server Configuration¶

Connect to multiple DataHub instances simultaneously. Useful for:

Production and staging environments
Multi-tenant deployments
Cross-environment metadata comparison

Setting Up Multiple Servers¶

# Primary server configuration
export DATAHUB_URL=https://prod.datahub.example.com/api/graphql
export DATAHUB_TOKEN=prod-token
export DATAHUB_CONNECTION_NAME=prod  # Optional: customize display name

# Additional servers as JSON
export DATAHUB_ADDITIONAL_SERVERS='{
  "staging": {
    "url": "https://staging.datahub.example.com/api/graphql",
    "token": "staging-token"
  },
  "dev": {
    "url": "https://dev.datahub.example.com/api/graphql"
  }
}'

Additional Server Options¶

Each additional server can override these settings (inherits from primary if not specified):

Field	Description
`url`	DataHub GMS URL (required)
`token`	Access token (inherits from primary)
`timeout`	Request timeout in seconds
`retry_max`	Maximum retry attempts
`default_limit`	Default search limit
`max_limit`	Maximum allowed limit
`max_lineage_depth`	Maximum lineage depth
`write_enabled`	Enable write operations (nil = inherit from primary)

Using Multiple Servers¶

Use datahub_list_connections to see available connections
Pass the connection parameter to any tool to target a specific server
If connection is omitted, the default (primary) server is used

# Example: Search staging server
datahub_search query="customers" connection="staging"

Getting a DataHub Token¶

Log into DataHub
Go to Settings > Access Tokens
Generate a new token with appropriate permissions
Copy the token value

Config File¶

As an alternative to environment variables, configure via YAML or JSON:

datahub:
  url: https://datahub.example.com
  token: "${DATAHUB_TOKEN}"
  timeout: "30s"
  connection_name: prod
  write_enabled: true

toolkit:
  default_limit: 20
  max_limit: 50
  descriptions:
    datahub_search: "Custom search description for your deployment"

extensions:
  logging: true
  errors: true

Load with extensions.LoadConfig("config.yaml") when using as a library. Environment variables override file values for sensitive fields. Token values support $VAR / ${VAR} expansion.

See the configuration reference for all options.

Security Considerations¶

Never commit tokens to version control
Use environment variables or secret management
Tokens should have minimal required permissions
Rotate tokens periodically