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start command

Start the Data API builder runtime with an existing configuration file.

Syntax

dab start [options]

Quick glance

Option Summary
-c, --config Use a specific config file (defaults to dab-config.json or environment-specific file if present)
--LogLevel <level> Sets log level explicitly (name or number 0–6)
--no-https-redirect Disables automatic HTTP→HTTPS redirection
--verbose Sets log level to Information

-c, --config

Path to the configuration file. Defaults to dab-config.json. If an environment-specific file dab-config.<DAB_ENVIRONMENT>.json exists, that file is used instead (DAB_ENVIRONMENT is read from the environment variable).

Behavior

  • If both the base and environment-specific file exist, the environment-specific file is chosen.
  • No mutation of config happens, start only consumes.

Note

Providing --config (or -c) overrides the environment-variable–based selection logic. If you pass a path explicitly, the DAB_ENVIRONMENT variable is ignored and only the specified file is used. This means environment-specific layering is bypassed. If you want automatic environment resolution, omit --config and rely on DAB_ENVIRONMENT plus the matching file naming convention.

Example

dab start --config ./settings/dab-config.json

--LogLevel <level>

Sets the minimum log level explicitly. Accepts names (Trace, Debug, Information, Warning, Error, Critical, None) or numeric values 0–6. Case-insensitive.

Behavior

  • Cannot be combined with --verbose.

  • Invalid values outside 0–6 cause startup to fail.

  • If neither --verbose nor --LogLevel is set, defaults are:

    • Development host mode: Debug
    • Production host mode: Error

Example

dab start --LogLevel Warning
dab start --LogLevel 1   # Debug

For more about levels, see .NET log levels.

Note

--LogLevel and --verbose always override any log level settings in the configuration file. Even if you do not supply a logging flag, the CLI injects a baseline log level when launching the runtime. As a result, per-namespace or fine-grained logger filters defined in configuration are not applied when using dab start.

--no-https-redirect

Disables automatic HTTP→HTTPS redirection.

Behavior

  • Default is secure redirection enabled.
  • Supplying this flag disables redirection.

Note

This flag only controls whether HTTP traffic is redirected to HTTPS. It does not create or remove endpoints. Endpoints are determined by ASPNETCORE_URLS (or Kestrel defaults).

  • If only HTTP is configured, the flag changes nothing because there is no HTTPS endpoint to redirect to.
  • If only HTTPS is configured, the flag changes nothing because there is no HTTP traffic to upgrade.
  • If both HTTP and HTTPS are configured, the flag suppresses the automatic redirect, allowing both endpoints to serve requests directly.

Example

dab start --no-https-redirect

--verbose

Sets the minimum log level to Information.

Behavior

  • Cannot be combined with --LogLevel.
  • Overrides host mode defaults.

Note

Equivalent to using --LogLevel Information. The parser prevents both --verbose and --LogLevel from being provided together, so there is no conflict path.

Example

dab start --verbose