The @client(merge=[context, ...]) decorator lets a mutation patch its
return value directly into the cached context bundle by matching the
mutation's Output type against each context-function's Output type
to identify the slot, then splicing server-side. Kernel runs
splice_slot on the response to apply locally — no refetch, no
invalidate-cascade.
Lands H14, H15, H16, M19, M20 from ISSUES.md.
Backends (Django + FastAPI):
_resolve_merges() in both executors walks @client(merge=...) targets,
resolves the per-context slot via types_match_for_merge, and emits
{context, slot, value, params?} entries on the response. Param
auto-scoping mirrors _resolve_invalidation's tier-1 logic.
Frontend kernel (mizan-base):
Response handler reads the merge[] array and applies splice_slot
for each entry — locates the cached context bundle by name+params,
overwrites the named slot with the new value, notifies subscribers.
Core (mizan-python):
@client decorator extended with merge= parameter. Schema export
threads merge metadata onto the OpenAPI x-mizan-functions entries.
Examples / fixtures:
fastapi-react-site harness exercises merge + Playwright spec covers
the end-to-end happy path (mutation → instant UI update without
network refetch). AFI fixture's rename_user function is the
canonical merge target.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Ryth Azhur
7fb0c4a400