Expression Functions Reference

This reference lists all available functions in KDeps expressions. These functions can be used in any field that supports string interpolation ({{ }}) or in expr blocks.

Core Functions

get(key, typeHint?)

Retrieves data from any source.

• key: The key to look up.
• typeHint (optional): Force a specific source (param, header, session, memory, item, env, file, filepath, filetype).

Examples:

get('q')                     # Auto-detect source
get('Authorization', 'header') # Get from headers
get('user_id', 'session')    # Get from session
get('API_KEY', 'env')        # Get environment variable

set(key, value, storage?)

Stores data in memory or session.

• key: The key to store.
• value: The value to store.
• storage (optional): Storage type (memory or session). Default is memory.

Examples:

set('count', 1)              # Store in memory (request-scoped)
set('user', data, 'session') # Store in session (persistent)

file(pattern, selector?)

Accesses uploaded files or local files.

• pattern: Glob pattern or file name.
• selector (optional): first, last, count, all, mime:<type>.

Examples:

file('*.jpg')                # Get all JPG files content
file('*.pdf', 'first')       # Get content of first PDF
file('*', 'count')           # Get total file count

info(field)

Retrieves request metadata.

• field: One of requestId, timestamp, path, method, clientIp, sessionId, filecount, files, filetypes.

Examples:

info('requestId')            # Get request ID
info('clientIp')             # Get client IP

Data Handling Functions

json(data)

Converts data to a JSON string.

• data: The data to stringify.

Examples:

json(get('userData'))        # Convert object to JSON string

safe(obj, path)

Safely accesses nested properties without panicking on nil values.

• obj: The object to access.
• path: Dot-notation path to the property.

Examples:

safe(user, "profile.address.city") # Returns city or nil if path invalid

debug(obj)

Returns a pretty-printed JSON string representation of an object for debugging.

• obj: The object to inspect.

Examples:

debug(get('httpResponse'))   # Inspect complex object structure

default(value, fallback)

Returns a fallback value if the primary value is nil or empty.

• value: The value to check.
• fallback: The value to return if primary is nil/empty.

Examples:

default(get('limit'), 10)    # Return 10 if limit is missing

Input/Output Functions

input(name, type?)

Accesses input data (similar to get but strictly for inputs).

• name: Input name.
• type (optional): param, header, body.

Examples:

input('q')                   # Get query param
input('body')                # Get request body

output(resourceId)

Accesses the output of a completed resource.

• resourceId: The actionId of the resource.

Examples:

output('llmResource')        # Get LLM output

Iteration Functions

item(type?)

Accesses current iteration context.

• type (optional): current, prev, next, index, count, values.

Examples:

item('current')              # Current item value
item('index')                # Current index (0-based)
item('count')                # Total items count

Session Functions

session()

Returns the entire session data object.

Examples:

session()                    # Get all session data