Templates and variables

Index templates

Templates allow you to reuse index configuration, e.g., for different networks (mainnet/testnet) or multiple contracts sharing the same codebase.

templates:
  my_template:
    kind: operation
    datasource: <datasource>
    contracts:
      - <contract>
    handlers:
      - callback: callback
        pattern:
          - destination: <contract>
            entrypoint: call

Templates have the same syntax as indexes of all kinds; the only difference is that they additionally support placeholders enabling parameterization:

field: <placeholder>

Template above can be resolved in a following way:

contracts:
  some_dex: ...

datasources:
  tzkt: ...

indexes:
  my_template_instance:
    template: my_template
    values:
      datasource: tzkt_mainnet
      contract: some_dex

Any string value wrapped in angle brackets is treated as a placeholder, so make sure there are no collisions with the actual values. You can use a single placeholder multiple times.

Any index implementing a template must have a value for each existing placeholder; the exception raised otherwise. These values are available in the handler context at ctx.template_values.

Environment variables

DipDup supports compose-style variable expansion with optional default value:

database:
  ...
  password: ${POSTGRES_PASSWORD:-changeme}

You can use environment variables throughout the configuration file, except for property names (YAML object keys).

💡 SEE ALSO

• 3.11. Index factories
• 14.16. templates