Control flow

Agentflow is built on the idea of programming with natural language. Prompting and AI generations will only get you so far - to be a true programming language some form of control flow is needed. Agentflow supports looping and conditional branching through the <Loop /> and <Cond /> actions.

Looping

Looping is a powerful, foundational programming concept that most modern, general-purpose programming languages provide through loop constructs or recursion. In Agentflow, the <Loop /> action lets you repeat part of your workflow until a condition is met.

<Loop
  as="history"
  until={2000 + $.index > new Date().getFullYear()}
  provide={{ year: 2000 + $.index }}>

  Write an interesting fact about the year: {year}

  <GenText as="fact" model="openai:gpt-4o" />
</Loop>

The <Loop /> action wraps around an inner block of workflow content, which has its own scope and is isolated from the parent scope. This introduces a new dynamic:

• Any attribute expressions on the <Loop /> action itself are evaluated with the context of the scope that the action is in - that is the parent scope.
• Any expressions nested inside the <Loop /> action are evaluated with the context of the inner, child scope.

Attributes

attribute	type	description	required
as	string	Unique variable name.	✅
until	boolean	Expression returning a boolean to determine when to break the loop.	✅
provide	object	Optional expression returning an object of keys and values that are provided to the child scope. Evaluated once at the start of

Both the until and provide expressions are evaluated at the beginning of every iteration.

The result of the loop will be stored in the workflow's state as a JSON array type using the name given in the as attribute.

Helper properties

In the loop example above, you may have noticed the use of $.index. This is a action helper. The <Loop /> action helpers allow the actions own attribute expressions and flow expressions within the child scope to introspectively access the current state of the loop.

property	type	description
index	number	The zero-based index of the current iteration within the loop.
self	array	An array of objects representing the accumulated state of all iterations of the loop.
last	object or undefined	The result of the previous iteration (undefined on the first iteration). Equivalent to $.self[$.self.length - 1].

Conditional branching

Conditional branching is another fundamental programming concept where the execution of code follows different paths depending on a specified condition. In Agentflow, the <Cond /> action lets define different blocks of workflow to be executed, depending on a condition.

<Cond as="weekday" if={dayOfWeek >= 1 && dayOfWeek <= 5}>
  It's a weekday. Suggest a quick, healthy breakfast idea for a busy
  professional.

  <GenText as="meal" model="openai:gpt-4o" />
</Cond>
<Cond as="weekend" if={dayOfWeek < 1 || dayOfWeek > 5}>
  It's the weekend. Propose a leisurely brunch recipe to enjoy with family
  or friends.

  <GenText as="meal" model="openai:gpt-4o" />
</Cond>

If/Else

For now, implementing an If/Else pattern requires multiple <Cond /> actions with mutually exclusive if conditions. In future, if/else and switch/case patterns will be possible with the <Cond /> action.

Attributes

attribute	type	description	required
as	string	Unique variable name.	✅
if	boolean	Expression returning a boolean to determine whether to execute the block.	✅
provide	object	Optional expression returning an object of keys and values that are provided to the child scope. Evaluated once at the start of

The <Cond /> action provides no helpers.