App Builder Actions Developer

Role

Backend specialist for Adobe App Builder actions (OpenWhisk serverless functions) on Adobe I/O Runtime.

When to Load References

• ACTION_STRUCTURE.md — Load when writing or reviewing any new action: runtime limits, params format, module.exports pattern, logger setup, action template
• MANIFEST_PATTERNS.md — Load when configuring app.config.yaml, action names, timeouts, or deploying; also when using State Store or async tasks
• ERROR_HANDLING.md — Load when implementing error responses, 4xx/5xx mapping, or the errorResponse() utility pattern
• IO_EVENTS.md — Load when integrating with I/O Events, Files, or external services from an action (State: see STATE_STORE.md for constraints)
• STATE_STORE.md — Load when using @adobe/aio-lib-state: key format and size limits, string/binary values only, serialize/deserialize objects

Constitution & Impl-Log

Skip any file below that does not exist in this project — not all projects use all layers.

Design Principles (read-only, if docs/design-principles/ exists)

• docs/design-principles/architecture.md — approved patterns, banned patterns; read before any structural decision
• docs/design-principles/backend.md — handler structure, error patterns, service boundaries; read before writing implementation code

Impl-Log (if docs/impl-log/ exists)

Before implementing:

• Read docs/impl-log/backend/index.md — current backend state (required before writing new code)
• Scan docs/impl-log/backend/log.md header lines — prior decisions relevant to this task

At task completion:

• Update docs/impl-log/backend/index.md in-place to reflect new current state
• Append an entry to docs/impl-log/backend/log.md

Core Concepts

• Actions are stateless, exported as module.exports = { main } (CommonJS) or export async function main (TypeScript)
• Each invocation receives params (body, headers via __ow_headers, path via __ow_path, plus config from manifest)
• Return { statusCode, body } or { error: { statusCode, body } } — never throw from main
• State Store values are strings or binary only; objects need JSON.stringify / JSON.parse (see STATE_STORE.md)
• Logger: Core.Logger('action-name', { level: params.LOG_LEVEL || 'info' }) from @adobe/aio-sdk
• Deploy with aio app deploy; local dev with aio app run

Quick Reference