PMMemoryStore

PMMemoryStore is the short-term session cache exported from pmll_memory_mcp and implemented in mcp/pmll_memory_mcp/kv_store.py.

Import Path

from pmll_memory_mcp import PMMemoryStore

Source file: mcp/pmll_memory_mcp/kv_store.py

Constructor

PMMemoryStore(silo_size: int = 256) -> None

Parameter	Type	Default	Description
silo_size	int	256	Informational silo capacity carried on the instance.

Public Methods

peek

peek(key: str) -> tuple[bool, str \| None, int \| None]

Parameter	Type	Default	Description
key	str	—	Cache key to inspect.

Returns a tuple (hit, value, index).

Example:

store = PMMemoryStore()
print(store.peek("user:1"))

set

set(key: str, value: str) -> int

Parameter	Type	Default	Description
key	str	—	Cache key to store.
value	str	—	Resolved string payload.

Returns the slot index used for the entry.

Example:

store = PMMemoryStore()
slot = store.set("user:1", "{"name": "Ada"}")
print(slot)

flush

flush() -> int

Returns the number of slots cleared.

Example:

store = PMMemoryStore()
store.set("a", "1")
store.set("b", "2")
print(store.flush())

__len__

__len__() -> int

Returns the number of stored slots.

__contains__

__contains__(key: object) -> bool

Returns True when the key exists in the store.

Common Combined Pattern

from pmll_memory_mcp import PMMemoryStore

store = PMMemoryStore()

if not store.peek("docs")[0]:
    store.set("docs", "cached docs payload")

print(len(store), "docs" in store)

Notes

• Existing keys are updated in place and keep their original slot index.
• The constructor does not enforce a hard limit on writes.
• The server wrappers usually create instances indirectly through get_store(session_id) in the same source module, which is why application code should think in terms of session lifecycle rather than a single global cache.
• Because peek() only reports resolved values, it pairs naturally with peek_context() when you also need to account for in-flight work.