Greenart7c3 builds Amber, a Nostr signer for Android that helps users keep private keys out of ordinary clients.
Public role in Nostr
Greenart7c3 is included here because of a visible public role in the Nostr universe: Amber signer and Android key-safety builder. The profile is intentionally focused on ecosystem work rather than private biography.
- Amber. Android signer that holds the nsec so other apps can request signatures without seeing the key.
- Citrine. Sibling Android Nostr infrastructure work referenced by OpenSats.
- Remote signing UX. Practical work around NIP-46 and app permissions.
Why this matters for the Nostr archive
Nostr is easier to understand when the protocol is connected to real builders and products. The ecosystem is not one company. It is a mesh of people building clients, relays, libraries, signers, wallets, media tools, community infrastructure and funding channels.
Crays relevance
For Crays, Amber is a model for key-safety UX. Any Crays login or voting flow should avoid teaching users to paste secrets into web pages.
How to keep this profile accurate
Use the source links below as the verification layer. Future edits should update roles, projects and dates from primary project pages, public repositories or funding announcements instead of copying unsourced summaries from random reposts.