bbgo_origin/doc/topics/developing-strategy.md

# Developing Strategy

There are two types of strategies in BBGO:

1. built-in strategy: like grid, bollmaker, pricealert strategies, which are included in the pre-compiled binary.
2. external strategy: custom or private strategies that you don't want to expose to public.

For built-in strategies, they are placed in `pkg/strategy` of the BBGO source repository.

For external strategies, you can create a private repository as an isolated go package and place your strategy inside
it.

In general, strategies are Go struct, placed in Go package.

## The Strategy Struct

BBGO loads the YAML config file and re-unmarshal the settings into your struct as JSON string, so you can define the
json tag to get the settings from the YAML config.

For example, if you're writing a strategy in a package called `short`, to load the following config:

```yaml
externalStrategies:
- on: binance
  short:
    symbol: BTCUSDT
```

You can write the following struct to load the symbol setting:

```
package short

type Strategy struct {
    Symbol string `json:"symbol"`
}

```

To use the Symbol setting, you can get the value from the Run method of the strategy:

```
func (s *Strategy) Run(ctx context.Context, session *bbgo.ExchangeSession) error {
    log.Println("%s", s.Symbol)
    return nil
}
```




## Built-in Strategy