# forge.param

- [Param](/reference/forge/param/Param.md): Base of every setting declaration. ``default`` is the only positional argument.
- [ParamError](/reference/forge/param/ParamError.md): A setting declaration, or a value given for one, is invalid.
- [describe_params](/reference/forge/param/describe_params.md): Every setting declared on ``cls`` and its bases, base settings first, in declaration order.
- [Bool](/reference/forge/param/Bool.md):
- [Choice](/reference/forge/param/Choice.md):
- [Color](/reference/forge/param/Color.md): Display only: a theme token (``theme.up``) or ``#rrggbb``. Never swept.
- [Decimal](/reference/forge/param/Decimal.md): A number with a fixed count of decimal places (02 LANG-085).
- [Enum](/reference/forge/param/Enum.md): A dropdown over a Python ``enum.Enum``; the default is one of its members.
- [Float](/reference/forge/param/Float.md):
- [Int](/reference/forge/param/Int.md):
- [MAX_CANDIDATES](/reference/forge/param/MAX_CANDIDATES.md):
- [MA_METHODS](/reference/forge/param/MA_METHODS.md):
- [MaMethod](/reference/forge/param/MaMethod.md): A moving-average method dropdown (04 IND-044).
- [Price](/reference/forge/param/Price.md): A price level, draggable on the Studio chart. ``None`` means unset.
- [Session](/reference/forge/param/Session.md): A time window like ``"07:00-10:00"``; several are comma separated.
- [Source](/reference/forge/param/Source.md): A price field (``close``, ``hl2``...) or another indicator's output.
- [Symbol](/reference/forge/param/Symbol.md): A symbol; ``None`` means the run's own symbol. Never swept.
- [Text](/reference/forge/param/Text.md): Display only: a short text. Never swept.
- [Time](/reference/forge/param/Time.md): A clock time like ``"16:55"``.
- [Timeframe](/reference/forge/param/Timeframe.md):
- [Volume](/reference/forge/param/Volume.md): Tick volume or real traded volume (04 IND-043).