The KB-persistence impl lived in shared/middleware/ but no subagent uses it --
consumers are the main_agent builder and the boundary event loop. Colocate with
its owner using the folder-per-middleware shape; __init__ re-exports the public
surface. Tests that reached module internals now alias the .middleware submodule.
main_agent/middleware/kb_persistence.py -> kb_persistence/builder.py
shared/middleware/kb_persistence.py -> kb_persistence/middleware.py
The busy-mutex impl (BusyMutexMiddleware + cancel/turn-lifecycle primitives)
lived in shared/middleware/ but no subagent uses it -- consumers are the
main_agent builder and the boundary (turn lifecycle). Colocate with its owner
using the folder-per-middleware shape; __init__ re-exports the public surface so
boundary import sites only change package path:
main_agent/middleware/busy_mutex.py -> busy_mutex/builder.py
shared/middleware/busy_mutex.py -> busy_mutex/middleware.py
memory (builder) + memory_injection (impl) lived in shared/middleware/ but are
consumed only by main_agent (no subagent, no shared plumbing). Colocate with
their owner using the folder-per-middleware shape:
shared/middleware/memory.py -> main_agent/middleware/memory/builder.py
shared/middleware/memory_injection.py -> main_agent/middleware/memory/middleware.py
Re-decide subagent_stack placement using the primary-built-for lens rather
than consumer-only: it assembles the middleware stack threaded into every
subagent, so its domain is subagents -- even though main_agent is its sole
caller (analogous to subagents/registry.py, also invoked from main_agent).
Since no subagent *sibling* imports it, it does not belong in subagents/shared/
but at the subagents/ package root:
main_agent/middleware/subagent_stack.py
-> subagents/middleware_stack.py
subagents/shared/middleware/ held build_subagent_middleware_stack, but no
subagent package imports it -- its only caller is main_agent/middleware/stack.py
(the generic pack_subagent builder merely consumes the resulting dict at
runtime). It is main_agent's policy for which middleware to thread into
subagents, so it belongs with its caller:
subagents/shared/middleware/middleware_stack.py
-> main_agent/middleware/subagent_stack.py
subagents/shared/ now holds only genuinely subagent-shared code (md_file_reader,
snippets, spec, subagent_builder, hitl).
Per-file verification of the slice-3 candidates showed receipts/ and
date_filters.py are shared contracts (consumed by shared/state + shared
middleware + subagents), so they correctly stay put.
permissions was the real misfit: the rule *model* lived at shared/permissions.py
while its enforcement lived at shared/middleware/permissions/. Unify them into a
single self-contained subsystem:
shared/permissions.py -> shared/permissions/model.py
shared/middleware/permissions/{deny,ask,middleware}
-> shared/permissions/{deny,ask,middleware}
The package __init__ re-exports the model API + build_permission_mw, so the 32
external model consumers keep importing `from ...shared.permissions import Rule`
unchanged; only the 8 internal files redirect to `.model` (cycle-safe, model
loaded before middleware).
Move the lower-level runtime/infra modules out of multi_agent_chat/shared/
(they were never used by subagents, so they failed the shared-by-all-siblings
rule) and unify them with the already-relocated checkpointer:
agents/runtime/ -> agents/chat/runtime/
mac/shared/errors.py -> chat/runtime/errors.py
mac/shared/llm_config.py -> chat/runtime/llm_config.py
mac/shared/prompt_caching.py -> chat/runtime/prompt_caching.py
mac/shared/mention_resolver.py -> chat/runtime/mention_resolver.py
mac/shared/path_resolver.py -> chat/runtime/path_resolver.py
These sit below the agent packages: the boundary + agent factory + shared
middleware depend on them, and they import no agent code (acyclic).
shared/sandbox.py was used only by the filesystem middleware/tools (and the
boundary) -- never by main_agent or subagents as shared code. Move it next to
its only agent-side consumer:
multi_agent_chat/shared/sandbox.py
-> multi_agent_chat/shared/middleware/filesystem/sandbox.py
Recursive shared-folder rule: a shared/ must be shared by ALL siblings at its
level. The kernel (context, compaction, retry_after, web_search) was shared by
only 2 of the agents -- anonymous_chat + multi_agent_chat -- never by podcaster
or video_presentation. Those 2 are the "chat" category, so their shared code
belongs in that category's shared/, not the top-level one.
app/agents/anonymous_chat/ -> app/agents/chat/anonymous_chat/
app/agents/multi_agent_chat/ -> app/agents/chat/multi_agent_chat/
app/agents/shared/ -> app/agents/chat/shared/ (anon<->mac kernel)
Top-level app/agents/shared/ is gone: nothing was shared across all three
categories (chat / podcaster / video_presentation).
~289 import sites rewritten (app.agents.{anonymous_chat,multi_agent_chat,shared}
-> app.agents.chat.*); all moves are git renames (history preserved).
app/agents/ now: chat/, podcaster/, video_presentation/, runtime/.
