16.4.0 (2026-06-01)
Features
- Add no-data chart overlays (#13471) (792aa92)
- agent: collapse agent context pills into a deck (#13516) (f1e0e2e)
- agent: make PXI quick actions dynamic per page context (#13534) (e60ba32)
- agents: add Claude Opus 4.8 support to PXI (#13497) (f13fd0b)
- agents: add span annotation tool (#13502) (4c8262c)
- agents: Floating chat drag, resize, style improvements (#13443) (79d8afe)
- agent: show a Beta badge in the PXI header on new chats (#13535) (1deb767)
- agents: trace debugging skill (#13467) (7ddc699)
- agents: upgrade eval harness with message history (#13474) (b8cc702)
- app: style code blocks with the Pierre theme for consistent light/dark (#13519) (a3ec631)
- filter: make span_kind comparisons case-insensitive (#13489) (a1970a3)
- lift trace UX feature flag (#13470) (f22e85b)
- playground skill (#13465) (8ec9392)
- surface PXI model credential setup (#13458) (566a1f5)
Bug Fixes
- adjust spans sparkline bar gap (#13500) (8da7337)
- avoid PXI initial scroll animation (#13456) (6a408ad)
- cost: update built-in model token prices (#13522) (d14a55c)
- keep PXI thinking indicator after tool calls (#13488) (dfd0ec6)
- load evaluator subclass fields in dataloader (#13449) (1a36841)
Documentation
- Add Phoenix release notes for 05-21-2026 through 05-27-2026 (#13446) (6200ae2)
- add ReleaseUpdate component with read more links (#13544) (ffa4762)
- agents: note python and node are unavailable in PXI bash tool (#13493) (1718c71)
- graphql: describe Span token count fields and TokenCountPromptDetails (#13491) (a2ffe12)
- introduce PXI agent (#13476) (c5fe607)
- skills: weekly audit — 2026-05-27 (3108194)