v21.2.0 — a brain for your agent, a registry for your own

Two doors open in this release: bring your own agent in, and build your own agents here.

AgentQon as a brain for your agent

• agentqon brain key mints a scoped brain key (aqb_…, shown once, stored hashed, revocable via agentqon brain revoke). The key works ONLY for the brain endpoint — it is refused on account and admin routes, and Shield's host/origin protections are unchanged.
• POST /v1/brain — one synchronous call; the full AgentQon pipeline answers (panel, critic, memory — sessions remember prior exchanges). No model connected still returns the honest 503; nothing is ever faked.
• agentqon brain prints the endpoint, key status, and copy-paste curl / Python / Node snippets with your key filled in.
• MCP bridge included — a one-file stdio MCP server exposing ask_agentqon, so MCP-native agents plug in directly.
• Guide: Use AgentQon as your agent's brain.

Custom Agent Registry (web UI)

• Add / Edit / Delete your own agents from the registry card: name, role, description, expertise (task types), instructions.
• Custom agents are full citizens, not a cosmetic list: they appear in the registry with a custom marker, are ranked by the suitability layer for their declared expertise, sit on live mission panels with their instructions driving their drafts, and accrue performance-ledger entries when they run.
• Human-readable validation everywhere (no raw 500s); mutations are admin-guarded and tenant-scoped.

Named buttons

Every one of the UI's 70 buttons now carries a stable name (e.g. mission-send, custom-agent-add), with aria-labels on icon-only controls — pinned by a contract test so no unnamed button ships again.

Also inside

Everything from the 21.1.x line: terminal progress bars, the boot watchdog, the error-surface pass, and the every-machine dependency fixes (Windows Intel/ARM, Intel + Apple-Silicon Macs, Linux).