Unified API

KDeps v2 simplifies data access with a unified API. Just a few core functions provide access to all data sources, replacing the complex API surface of previous versions.

Core Functions

These functions are available in all expression contexts (string interpolation {{ }} and expr blocks).

1. get()

The workhorse function for retrieving data. It uses a smart priority chain to find what you're looking for.

# Auto-detect source
query: get('q')

Priority Chain:

1. Items (Iteration context)
2. Memory (Request-scoped storage)
3. Session (User persistent storage)
4. Outputs (Resource execution results)
5. Query (URL parameters)
6. Body (Request body)
7. Headers (HTTP headers)
8. Files (Uploaded files)
9. Metadata (System info)

Explicit Source: You can bypass the chain by specifying a type hint:

get('q', 'param')      # Force query/body param
get('auth', 'header')  # Force header
get('user', 'session') # Force session

2. set()

Stores data for later use.

# Store in memory (current request only)
expr:
  - set('count', 1)

# Store in session (persists across requests)
expr:
  - set('user_id', '123', 'session')

3. file()

Accesses file content.

# Get uploaded file content
content: file('doc.pdf')

# Get by pattern
images: file('*.jpg')

4. info()

Accesses request and system metadata.

id: info('requestId')
ip: info('clientIp')
path: info('path')

Advanced Functions

For more specialized needs, additional helper functions are available:

• json(data) - Convert data to JSON string
• safe(obj, path) - Safely access nested properties
• debug(obj) - Inspect objects
• default(val, fallback) - Handle missing values

See the Expression Functions Reference for the complete list.

Resource Accessors

While get('resourceId') is the standard way to access outputs, resource-specific accessors provide granular data:

• Python/Exec: python.stdout('id'), python.stderr('id'), python.exitCode('id')
• HTTP: http.responseBody('id'), http.responseHeader('id', 'Name')
• LLM: llm.response('id'), llm.prompt('id')

These are typically used in expr blocks for conditional logic or error handling.

Next Steps

• Request Object - HTTP request data and file methods
• Resources Overview - Learn about resource types
• Tools - LLM function calling
• Workflow Configuration - Session settings