Part 3 — Extending

Part 3 covers extending a Pico beyond a single, isolated artifact. You will give a Pico a cryptographic identity, connect Picos across meshes, separate who a Pico is from what it may do, and prepare a Pico for portability between execution environments.

These lessons are based on the Pico-to-Pico identity architecture introduced in Pico Engine 1.6 and are designed to be completed in order after Part 1 — Foundations and Part 2 — Building.

Lessons

• 1. Pico Identity — did:webvh as a Pico’s public cryptographic identity and did:peer as relationship-specific identity.
• 2. Cross-Mesh Communication — DIDComm, subscriptions as cryptographic relationships, and how parent/ child communication differs from external relationships.
• 3. Trust and Authorization — keeping identity and authorization separate, channel policy, and the implications for Open Engineering rules and parsers.
• 4. Portability — what it takes to move a Pico between engines without losing who it is.
• 5. Hands — giving a Pico the ability to act on the world, with provider-neutral capabilities and governed execution.
• 6. Nervous System — giving a Pico an event-driven way to sense, communicate, and coordinate through a provider-neutral Pico Agent Transport, with EMQX/MQTT as a candidate adapter.

Each lesson follows the same page layout as the rest of the course — see the course overview for the full pattern.