Two kinds of strategy
Claude can write a strategy in two forms. A Rules strategy is a small graph of Orbital's rule cards: a universe, indicators, rules, sizing and an output. A Program strategy replaces the rules with a Rust function that Orbital compiles and calls on every bar. Both use the same tools, which The eleven tools lists.
Rule cards
Claude sends a strategy as nodes and the connections between them. Each node has an id, a type and a config. The authoring guide, get_authoring_guide with topic rule_card, gives Claude the recipe, every node's schema and one valid example. Each node type is one node in Orbital; see every node's fields.
| Node type | Node in Orbital |
|---|---|
| universe-input | Input, with its Source set to Universe |
| indicator | Indicator |
| entry-rule | Entry Rule |
| exit-rules | Exit Rules |
| sizing | Position Sizing |
| session-filter | Session Filter |
| regime-filter | Regime Filter |
| risk-guard | Risk Guard |
| program | Program |
| output | Output |
Indicators are wired into the rules that read them. The rules chain in a fixed order: Entry Rule, Exit Rules, Position Sizing, Output. The Input node and the three optional nodes need no wiring; Orbital finds them by type.
The guide's example is the same SPY golden cross that Your first strategy builds by hand.
A Rules strategy can declare parameters, which Claude sends as declared_parameters when it saves and sets by name in run_backtest; see Parameters a run can vary.
Programs
A Program is a Rust function that Orbital compiles and calls once per symbol on every bar of the decision bar you pick, in place of the Entry Rule and Exit Rules nodes; the universe and the sizing keep their own nodes. Write one when the rule needs memory across bars, the session clock, a conviction score to rank on, or a stop the rule cards have no node for; see What a Program is.
The Program node's Decision bar, History the program reads (bars of the decision bar), Parameters and Module reference are decision_timeframe, warmup_bars, parameters and module_ref; see the Program node's fields.
Claude reads the manual (get_authoring_guide with topic program), saves with create_strategy and allow_incomplete_config set to true, builds with build_program, then estimates and runs; see A Program from Claude or an agent.
A run refuses a Program whose source changed since its last build. A Program has no declared parameters: to try other values, Claude saves the graph again with the node's Parameters changed, and the build still stands.
Versions
Every save and every build writes a new version hash, and Orbital refuses a save built on a version Claude has not read, such as your own edit in the editor, so nothing is overwritten. The numbered versions Orbital shows, v1, v2 and the one marked Main, are recorded only when a run is launched or when you save a version in the editor; see Versions.
Where to find it in Orbital
Open Backtesting: the Strategies list holds every strategy in the project, including those Claude created. On a strategy's page, Workflow ↗ opens a Rules strategy's graph, and Code ↗ opens a Program in the Program editor, where Build and Test live.