v0.5.4

Added

• Added set_prefab_property and set_prefab_properties for field-level edits on regular and variant prefab assets without opening Prefab Mode. The tools require normalized Assets/**/*.prefab paths, reject ambiguous hierarchy/component matches unless an explicit index is supplied, write serialized fields only, save through PrefabUtility, synchronously reimport, and return persisted readback. Both tools are included in the default core profile.
• Added parameterized built-in MCP workflows for safe prefab edits, compilation checks, Play Mode recovery, serialized-reference wiring, and playable prototypes. Required and unknown arguments are validated by prompts/get, and prompts can best-effort embed relevant read-only Unity resources.
• Projects can register validated workflow prompts through root-level mcp-prompts/*.md files without forking the package. Malformed, duplicate, oversized, or reserved definitions are skipped with a visible warning; changes are loaded after an MCP server restart or Unity domain reload.
• The MCP initialize response now includes concise cross-client instructions for Unity serialization, object identity, compilation/reload recovery, console inspection, and screenshot transport behavior.

Changed

• Broker protocol bumped to v3 (no client-facing wire change). A pre-v3 broker still running after a package upgrade now fails the new health probe and is replaced in place, so the stale-session sweep below takes effect immediately on upgrade rather than only after the next natural broker restart. EnsureRunning also waits for the port to be released after shutting down its own recorded broker, so a same-port in-place replacement (which a protocol bump triggers) completes in a single call instead of bailing as "port in use" while the just-closed socket lingers.

Fixed

• The keepalive broker now sweeps stale attached sessions instead of remembering them forever. A crashed or force-killed editor never sends a detach, so its session lingered in the broker's attached-session set indefinitely and defeated the fast-fail gate for client requests: new requests were queued and held up to the 300s hold deadline instead of failing fast once the only backend was gone. Sessions now carry a last-seen timestamp (refreshed on attach and every pull) and are swept after a staleness window (default = the 300s hold deadline, so a domain-reload/compile gap never evicts a live-but-reloading session; overridable via FUNPLAY_BROKER_SESSION_STALE_MS). The sweep skips the session whose long-poll is currently parked (provably alive) and reconciles a swept session's in-flight work exactly like an explicit detach — failing still-queued requests only when no backend remains, so a dead session swept while a healthy one is connected leaves those requests for the healthy session.
• Prefab Mode save and close responses now warn when UGUI layout, TMP auto-size, or Spine components are present because edit-time derived state may be included in the full-graph save. Field-only changes can use the new asset-level setters to avoid Prefab Stage recomputation.
• MCP Server transport labels now show an in-progress state and refresh only after the service-owned settings restart settles. Transport, port, and broker-path changes no longer race a fixed two-frame refresh or start a second competing Stop/Start sequence from the window; rapid setting changes are coalesced, and disabling the server during a pending restart no longer starts it again.

Contributors

• Thanks @dehuaichendragonplus for the stale broker-session recovery work in #47, the prefab asset-editing proposal and implementation in #45, the parameterized prompt architecture in #46, and the transport status refresh fix in #48.