# forge.indicator

- [Band](/reference/forge/indicator/Band.md): Shade (or draw as bars) the space between two sides of one indicator.
- [Data](/reference/forge/indicator/Data.md): Another series an indicator reads: a timeframe, a symbol, a bar type or a price.
- [Indicator](/reference/forge/indicator/Indicator.md): The one base class of an indicator (IND-001: declared by subclassing, never inferred).
- [Level](/reference/forge/indicator/Level.md): A horizontal line in the indicator's pane: ``fg.Level(70, "Overbought")``.
- [Output](/reference/forge/indicator/Output.md): Output declarations. Each takes a label; the name is the attribute it is assigned to.
- [BAR_TYPES](/reference/forge/indicator/BAR_TYPES.md):
- [DECLARABLE_EXCEPTIONS](/reference/forge/indicator/DECLARABLE_EXCEPTIONS.md):
- [FORMATS](/reference/forge/indicator/FORMATS.md):
- [LIVE_CADENCES](/reference/forge/indicator/LIVE_CADENCES.md):
- [MANIFEST_SCHEMA](/reference/forge/indicator/MANIFEST_SCHEMA.md):
- [check_causality_exceptions](/reference/forge/indicator/check_causality_exceptions.md): The declared causality exceptions: output names to ``DECLARABLE_EXCEPTIONS``.
- [check_data_declarations](/reference/forge/indicator/check_data_declarations.md): The checks that need the whole class. Raises ``ValueError`` with its rule id as prefix.
- [check_output_declarations](/reference/forge/indicator/check_output_declarations.md): The checks that need the whole class: shift names and the price pane.
- [check_repaints](/reference/forge/indicator/check_repaints.md): ``repaints`` is ``True`` or ``False``; anything else is ``metadata_invalid``.
- [check_timeframe_attribute](/reference/forge/indicator/check_timeframe_attribute.md): The class ``timeframe`` in C1's spelling, or a setting's name.
- [describe_bands](/reference/forge/indicator/describe_bands.md): One manifest entry per band, in declaration order.
- [describe_outputs](/reference/forge/indicator/describe_outputs.md): One manifest entry per output, in declaration order (all keys always present).
- [normalize_timeframe](/reference/forge/indicator/normalize_timeframe.md): A timeframe in C1's spelling: ``M7``, ``H4``, ``D1``, ``W1``, ``MN1``.
- [output_styles](/reference/forge/indicator/output_styles.md): Every output's style with its default colour filled in.
- [timeframe_ns](/reference/forge/indicator/timeframe_ns.md): The length of a C1 timeframe in nanoseconds, or ``None`` for a month (no fixed length).
- [use_call_targets](/reference/forge/indicator/use_call_targets.md): The first argument of every ``self.use(...)`` in the class's methods, in source order.
- [use_target_key](/reference/forge/indicator/use_target_key.md): The registry key a ``self.use`` first argument names; ``use_invalid`` when it names none.
- [uses_from_source](/reference/forge/indicator/uses_from_source.md): The built-in indicators this class names in ``self.use(...)``, sorted, each once.
- [warmup_expression_from_node](/reference/forge/indicator/warmup_expression_from_node.md): One warm-up expression from a literal, a ``lambda self: ...`` or a ``def warmup(self)``.
- [warmup_manifest_from_node](/reference/forge/indicator/warmup_manifest_from_node.md): The warm-up manifest from a ``warmup`` node: what the class and the load check both say.
- [warmup_node](/reference/forge/indicator/warmup_node.md): The class's ``warmup`` assignment value or ``def warmup``, or ``None``.