spectrum

This skill helps an agent build or review messaging agents with Photon's Spectrum SDK (`spectrum-ts`, targeting version 12.2.0). Spectrum is a unified messaging SDK: you write handler logic once against a single `app.messages` stream and deliver it through iMessage, WhatsApp Business, a Terminal TUI, or a custom provider. The skill solves the problem of writing provider-correct messaging code by enforcing a "contract gate" — identify the provider and load its topic file before writing provider-specific code, because a universal method existing does not guarantee every provider implements it.

The skill is organized as a set of focused topic files, each consulted per question: getting-started (installation, the `Spectrum()` app instance, multi-platform setup, core primitives), messages (the `Message` shape and narrowing on content type), content builders (text, markdown, attachment, voice, contact, richlink, app, poll, group, custom), spaces and users, reactions and threaded replies, capability semantics (native support vs fallback, warn-and-skip, accepted no-op, thrown errors), platform narrowing, per-provider guides (iMessage cloud/local, Terminal, WhatsApp Business 1:1-only), custom events and lifecycle, and authoring custom platforms with `definePlatform`. A substantial best-practices file documents the production architecture Photon uses internally — a debounce pipeline, in-flight cancellation, carry-forward of drained messages, idempotent retries with stable client GUIDs, per-resource memory, and job-failure audit logging — illustrated with mermaid diagrams.

It targets TypeScript developers building conversational or notification agents that live natively inside instant-messaging apps, and reviewers checking such code for provider-contract correctness. The content is reference and architecture guidance; it contains no destructive operations, credential exfiltration, or remote code execution.