polign-recall

A Python client for Recall's typed, correctable agent memory. Requires Python 3.10+.

pip install polign-recall

That is the whole install. pip also brings the polign_db package, which holds the polign CLI and polign-server binaries for Linux, macOS and Windows, so there is nothing else to download.

from polign_recall import Client

with Client(local_dir="./recall-data") as memory:
    memory.remember("user", "prefers_editor", "vim")
    changed = memory.remember("user", "prefers_editor", "neovim")
    print(memory.recall("user", "prefers_editor")[0].value)  # neovim
    print(memory.history("user", "prefers_editor"))  # both statements
    memory.forget("user", "prefers_editor", "neovim")

local_dir keeps the database on this machine. The first client to open the directory starts a polign-server for it in the background, listening on localhost only and protected by a key stored in the directory. Later clients, including ones in other processes, share that server. It keeps running after your program exits; its process id is in runtime.json and its log in server.log, both inside the directory. Managed local databases work on Linux and macOS.

To use a server you run yourself, leave local_dir out and set POLIGN_URL, POLIGN_API_KEY, and POLIGN_COLLECTION in the environment, or pass env={...} to Client. With neither, the client connects to http://localhost:23000, where polign-server -store fs:./recall-data listens by default.

The client owns a long-lived polign mcp -memory-only -write subprocess and shares the Go implementation's validation and fold. Use write=False for a read-only connection. It runs the polign binary pip installed; on a platform without a polign_db wheel it runs polign from PATH (CLI v0.7.0+), and command=[...] overrides both.

remember(text=..., statements=[...]) accepts proposals from your agent's model; the client does not run a second model. Every statement must have subject, predicate, typed value, and evidence quoting the text exactly. Read predicates() to build your extractor prompt. No separate extraction tool is required.

recall(..., as_of=...) accepts an RFC3339 string or timezone-aware datetime. forget requires a typed value or explicit all=True; false and zero remain values. Forgetting retracts a belief and retains its historical events.

Errors raise RecallError with a code and, for a failed extraction batch, any reported partial results. Calls are serialized, timeout after 120 seconds by default, and never automatically retry writes. A timeout closes the transport; inspect history using a new client before retrying an uncertain write.

Resuming an agent

An agent that crashes or moves to another machine can pick up from its own records instead of a snapshot of its process. Open the client with agent=True and call resume:

from polign_recall import Client

with Client(local_dir="./recall-data", agent=True) as client:
    with client.resume("billing-migrator") as agent:
        print(agent.context.briefing)  # hand this to the model as its starting context
        agent.update_working_state(goal="Move billing to the v2 API",
                                   plan=["find call sites", "migrate them", "run the tests"])
        agent.record_turn("user", "Start with the charge endpoint.")
        agent.set_pointer("wip", "git_ref", {"repo": "github.com/acme/billing", "branch": "agent/wip"})
        agent.milestone("call sites found", progress="12 call sites listed")

The first resume of an id starts the agent fresh (context.fresh is true). Every later one rebuilds context from what the agent wrote: its working state, pointers to its work, relevant memories, and its most recent turns, trimmed to token_budget. context.briefing is all of that as one text for the model; the same parts are also there as fields.

resume takes a lease on the agent id, so only one process acts for it at a time. While another process holds it, resume raises RecallError with code "lease_held". The lease is renewed in the background and handed over when you call release(), leave the with block, or close the client.

If the process before crashed without releasing, resume has to wait for its lease to expire. When you cannot wait, as on a live call, pass defer_lease=True: resume returns the context at once without the lease, because reading cannot conflict with anyone. Writes then raise RecallError with code "lease_not_held", so keep them in a buffer and call agent.acquire() until it returns True:

agent = client.resume("call-42", defer_lease=True, lease_ttl=6)
greet_with(agent.context.briefing)  # no waiting
while not agent.acquire():          # False while the crashed process's lease is live
    time.sleep(1)
agent.record_turn("assistant", "Sorry, we got cut off.")

Once it holds the lease, anything the crashed process wrote after the resume is picked up, and new turns continue after it.

The other methods write what the next resume reads: update_working_state (fields you leave out are kept), milestone, record_turn (a turn longer than the output threshold is stored whole and the turn keeps a reference), store_output and fetch_output for large tool results, set_pointer, remove_pointer and pointers, and recent_turns and working_state_history to read back. Needs a polign CLI newer than 0.7.4, the first with polign mcp -agent.