Syntax

Flow · Quick start

Flow is designed to be read from top to bottom. Most lines say one thing. Four spaces show the few places where the path branches, repeats, or contains literal text.

A file at a glance

# Values can be stored and reused.
SET limit = 3

ASK "How many items should I review?" AS count
IF @count == ""
    RETURN "A count is required."

DO Review up to @limit items requested by @count. AS review
PRINT @review

Commands are uppercase. Bindings such as limit and review hold values; references such as @limit read them.

Layout keeps the path visible

Use uppercase commands and four spaces for each indentation level. A block must have a body. Dedenting closes it; block headers have no colon or closing keyword. Semicolon separators are not supported.

Each .flow file contains one flow. Markdown can contain a fenced flow block. Blank lines are optional. Tabs are allowed only in literal bodies and raw strings.

Write one instruction per line, except for prose continuations, literal bodies, and multiline strings. Ordinary strings and expressions stay on one line, except for triple-quoted string values. Block and RUN headers stay single-line; pass multiline values through bindings.

Comments

# One-line comment.
###
A comment across
several lines.
###

Comments may be indented. Inline comments are unsupported. Multiline comments do not nest and must close. Comment markers inside strings or literal bodies are ordinary text.

Values and references

AS name stores a result in a binding. @name reads it; @order.total reads an object field. This lets one instruction hand real data to the next without copying it into another prompt. Names start with a lowercase letter and contain lowercase letters, digits, or underscores. They are case-sensitive. Rebinding replaces the previous value after the new instruction succeeds.

SET name = "Ana"
SET count = 3
SET approved = TRUE
SET result = NULL
SET names = ["Ana", "Vinod"]
SET order = {"total": 25, "currency": "USD"}
PRINT @order.total

Unknown bindings and missing fields are errors. References in task prose supply data; their values never become Flow instructions. In expressions, "@name" is literal text.

Strings

Ordinary strings use double quotes and JSON escapes, such as "line one\nline two". Use triple double quotes when the text should stay exactly as written:

SET message = """First line.
Second line with "quotes", @name, and # literal text.
"""
PRINT @message

Everything between """ delimiters stays unchanged: indentation, blank lines, tabs, backslashes, and leading or trailing newlines. There is no escape processing, interpolation, comment parsing, or instruction execution. The next """ closes the string; a missing closer is an error.

Use multiline strings wherever a string value is accepted, including ASK, SET, PRINT, and custom command inputs. The instruction counts once. Block and RUN headers remain single-line; pass multiline values through bindings.

Expressions

Expressions handle small, exact decisions. Keep work that needs judgment inside DO or a natural-language condition.

Operators are listed from highest to lowest precedence:

Operators	Meaning
(...), field access	Grouping and object fields.
+, -	Numeric arithmetic.
==, !=, <, <=, >, >=	Comparisons.
NOT	Boolean negation.
AND	Boolean and.
OR	Boolean or.

There is no implicit type conversion. Arithmetic needs numbers; Boolean operators need Booleans. Ordered comparisons need two numbers or two strings. Strings are case-sensitive. Equality requires matching types and compares arrays and objects structurally. Type mismatches are errors.

AND and OR short-circuit. Chained comparisons are unsupported; join separate comparisons with AND. Evaluate expressions precisely, using code when needed. There are no built-in functions such as trim() or JSON(); use DO, RUN, or a custom command.

Long prose and literal bodies

When a task needs a little more detail, continue DO or prose PRINT one level deeper without a blank line:

DO Write a greeting for @name.
    Keep it short and friendly. AS greeting

Continuation lines are prose, not nested instructions. Join them with single spaces; put optional AS name at the end of the final line.

CONTEXT and RUN bodies are literal. Remove one structural indentation level; preserve remaining whitespace and line breaks. Commands, references, and comments inside them are data, with no interpolation.

Next, see what each verb does in the command reference.