Stores and Scale

An agent keeps its state in a few stores, each with its own job. By the end of this page you will have a run that pauses in one process and is resumed by another, over one SQLite file, and you will know which store to change when one process becomes several, and several become several servers.

Every output on this page is what the code printed when it was run. The model’s wording and the ids will differ on your run.

Pause in one process, resume in another

Three files: the agent’s definition, a process that runs until a policy asks for approval, and a process that finds the waiting run, approves it and resumes it.

One definition, shared

# agent_def.py: the agent, built the same way in every process.
import os

os.environ.setdefault("DATABASE_URL", "sqlite:///./agent.db")

from omnicoreagent import MemoryRouter, OmniCoreAgent, ToolRegistry
from omnicoreagent.governance import PolicyEffect, PolicyRule, build_default_policy

tools = ToolRegistry()

@tools.register_tool("delete_report")
def delete_report(name: str) -> dict:
    """Delete a saved report."""
    return {"deleted": name}

policy = build_default_policy("interactive-dev")
policy.rules.ask.append(
    PolicyRule(rule_id="ask_before_deleting", effect=PolicyEffect.ASK,
               capability="tool.local.call", target={"tool_name": "delete_report"})
)

def build_agent(router: MemoryRouter) -> OmniCoreAgent:
    return OmniCoreAgent(
        name="reports",
        system_instruction="You manage saved reports. Answer in plain text, in one sentence.",
        model_config={"provider": "openai", "model": "gpt-5.4-mini"},
        local_tools=tools,
        memory_router=router,
        agent_config={"governance_config": {"enabled": True, "policy": policy}},
    )

SQLite goes through SQLAlchemy: pip install "omnicoreagent[postgres]".

Process one: run until it pauses, then exit

# ask.py
import asyncio
from omnicoreagent import MemoryRouter
from agent_def import build_agent

async def main():
    router = MemoryRouter("sql")
    try:
        agent = build_agent(router)
        result = await agent.run("Delete the report called q2-draft.", session_id="team-7")
        print(result["status"], result["run_id"])
        await agent.cleanup()
    finally:
        await router.close()

asyncio.run(main())

awaiting_approval run_b2949687af8645f8a64b42d09a1bd9f5

Process two: find waiting runs, approve, resume

# approve.py
import asyncio
from omnicoreagent import MemoryRouter
from agent_def import build_agent

async def main():
    router = MemoryRouter("sql")
    try:
        agent = build_agent(router)
        for waiting in await agent.list_runs(status="awaiting_approval"):
            run = await agent.get_run(waiting["run_id"])  # approvals with their arguments
            for approval in run["approvals"]:
                if approval["status"] == "pending":
                    print("approving:", approval["tool_name"], approval["arguments"])
                    await agent.resolve_approval(
                        run["run_id"], approval["approval_id"], decision="approve", approver="dana"
                    )
            result = await agent.resume(run["run_id"])
            print(result["status"], "|", result["response"])

            story = await agent.get_run_trajectory(run["run_id"])
            print("segments:", [segment["status"] for segment in story["segments"]])
        await agent.cleanup()
    finally:
        await router.close()

asyncio.run(main())

approving: delete_report {'name': 'q2-draft'}
success | Deleted the report q2-draft.
segments: ['suspended', 'completed']

Process two never saw the request; it found the run in the store, with the call’s arguments, and finished it. get_run_trajectory joined the first process’s trace (suspended) and its own (completed), because both ran in the same directory and so shared ./workspace/telemetry/. What was left on disk:

./agent.db
./workspace/telemetry/traces-archive/.bodies.locks/9155934a567bf748a841190093541d14.lock
./workspace/telemetry/traces-archive/.bodies.locks/b29a3de7565d810cf27591313f407969.lock
./workspace/telemetry/traces-archive/bodies/trace_c111931bb26f42618f2ff7d1015d36e7.json
./workspace/telemetry/traces-archive/bodies/trace_e1cf65fb2f68422490ebb404e055808e.json
./workspace/telemetry/traces-archive/index.sqlite
./workspace/telemetry/traces.jsonl

agent.db holds three tables: messages (session history), run_states (run records) and budget_states (budget counters). The traces are the workspace/telemetry/ files.

list_runs and get_run both give each approval’s arguments: the call as the model made it, for the person deciding.

Which store holds what

What	Kept in	Chosen with	Default
Session history	The memory store	`memory_router=MemoryRouter(...)`	In this process
Run records (status, calls, approvals, usage)	The memory store	the same	In this process
Budget counters	The memory store	the same	In this process
Traces (the trajectory of each run)	The telemetry log and its archive	`telemetry_config`	`./workspace/telemetry/` on disk
Offloaded payloads (large trace values)	Beside the traces, or the bucket	`telemetry_config["offload_target"]`	Off
Background tasks, schedules and their runs	The task store	`BackgroundAgentManager(task_store=...)`	In this process
The agent’s files	The workspace	`workspace_config`	`./workspace/` (Workspace files)

The memory store

Session memory, run records and budget counters share one store:

`MemoryRouter(...)`	Set	Install	Reaches
`"in_memory"` (default)	—	—	This process only; gone when it ends
`"sql"`	`DATABASE_URL`: `sqlite:///./agent.db` or `postgresql://user:pass@host/db`	`omnicoreagent[postgres]`	SQLite: processes on one machine. PostgreSQL: every server that can reach it
`"redis"`	`REDIS_URL`, e.g. `redis://host:6379/0`	`omnicoreagent[redis]`	Every server
`"mongodb"`	`MONGODB_URI`; optional `MONGODB_DB_NAME`, `MONGODB_COLLECTION`	`omnicoreagent[mongodb]`	Every server

Records and counters are saved with compare-and-swap on every backend, so two processes cannot both take over one run or both spend the last of a budget. Build one router per process and share it between agents: an agent built without one gets its own in-memory store, which no other agent sees. History windows and summaries: Memory.

Traces

Each finished run’s trace moves from a write-ahead log to an archive: one body per trace, and an index to find them.

`telemetry_config`	Default	What it does
`storage`	`"auto"`	`auto` or `jsonl`: the log on disk. `memory`: this process only (up to `memory_max_traces`, 1000)
`storage_path`	`workspace/telemetry/traces.jsonl`	The log. The archive sits beside it, in `traces-archive/`
`archive_index_url`	none: `index.sqlite` in the archive	A database URL, so several processes share one index
`archive_bodies_path`	none: `bodies/` in the archive	A directory the processes share (one host, or a shared volume)
`archive_target`	`"local"`	`"object_storage"`: bodies in the S3 or R2 bucket of the agent’s workspace

The trace log stays on local disk even when the workspace is S3 or R2. A process that reads another’s run needs its traces: run both in one directory (as above), or share the archive. Processes that run at the same time each keep their own log and share the archive: every process then answers for every finished trace, and stream positions stay unique across them.

import os
from omnicoreagent import OmniCoreAgent

agent = OmniCoreAgent(
    name="reports",
    system_instruction="You manage saved reports. Answer in plain text.",
    model_config={"provider": "openai", "model": "gpt-5.4-mini"},
    telemetry_config={
        "storage_path": f"/var/lib/agent/{os.environ['HOSTNAME']}/traces.jsonl",  # this process's own
        "archive_index_url": os.environ["DATABASE_URL"],                         # shared
        "archive_target": "object_storage",                                      # shared bucket
    },
)

To try it on one machine, stand in a SQLite file for the database and a directory for the bucket, and start two servers at once:

# worker.py: one of two servers; its own log, one shared archive.
import asyncio, sys
from omnicoreagent import OmniCoreAgent

async def main(name: str, question: str):
    agent = OmniCoreAgent(
        name="reports",
        system_instruction="You manage saved reports. Answer in plain text, in one sentence.",
        model_config={"provider": "openai", "model": "gpt-5.4-mini"},
        telemetry_config={
            "storage_path": f"./{name}/traces.jsonl",           # this process's own
            "archive_index_url": "sqlite:///./shared/index.db",  # shared
            "archive_bodies_path": "./shared/bodies",            # shared
        },
    )
    result = await agent.run(question, session_id=name)
    print(name, "ran", result["run_id"])
    await asyncio.sleep(3)  # let the other server finish its run too
    for trace in await agent.list_telemetry_traces():
        print(name, "sees", trace["run_id"], trace["status"], "from", trace["session_id"])
    await agent.cleanup()

asyncio.run(main(sys.argv[1], sys.argv[2]))

python worker.py server-a "Name one good title for a quarterly report." &
python worker.py server-b "Name one good title for a yearly report."
wait

server-a ran run_0ecde1bcc4a240b68d1c446e9fb35c0f
server-a sees run_0ecde1bcc4a240b68d1c446e9fb35c0f completed from server-a
server-a sees run_320d5a7eb32c4a50b4347554bcb537ad completed from server-b
server-b ran run_320d5a7eb32c4a50b4347554bcb537ad
server-b sees run_0ecde1bcc4a240b68d1c446e9fb35c0f completed from server-a
server-b sees run_320d5a7eb32c4a50b4347554bcb537ad completed from server-b

Each server lists both runs, its own from its log and the other’s from the shared archive. What was left on disk:

./server-a/traces.jsonl
./server-b/traces.jsonl
./shared/.bodies.locks/6f8deb7b26402ae6206e06ebeb8a45fa.lock
./shared/.bodies.locks/b18851d4ddc6caf465f7b958e73ebd79.lock
./shared/bodies/trace_0b117c9bcaa04202a194a5354f717e8b.json
./shared/bodies/trace_91c25e3c8d9a43eaa6ad0c70caac8da4.json
./shared/index.db

An archive that cannot be written to never fails a run: the trace stays in the log, and the store counts it in archive_failures with last_archive_error.

Offloaded payloads

A trace value larger than max_payload_bytes (64,000) is truncated, unless offload_large_payloads is True: then it is kept whole and the trace points to it (telemetry://payload/...). It is kept in the workspace’s telemetry/payloads (or beside storage_path), or with offload_target: "object_storage" in the workspace’s bucket, where every server can read it. await agent.read_telemetry_payload(reference) reads one.

Background tasks

BackgroundAgentManager(task_store=...) keeps tasks, schedules, runs, attempts and leases:

`task_store`	Reads	Install
`"in_memory"` (default)	—	—
`"sql"`	`DATABASE_URL`, or a SQLite file at `.omnicoreagent/background.db`	`omnicoreagent[postgres]`
`"redis"`	`REDIS_URL`	`omnicoreagent[redis]`
`"mongodb"`	`MONGODB_URI`, `OMNICOREAGENT_BACKGROUND_TASK_STORE_DATABASE`	`omnicoreagent[mongodb]`

Or a dict, such as {"backend": "sql", "url": "postgresql://..."}. Several managers on one durable store divide the runs between them, and a run a dead worker held is taken over when its lease lapses. More in Background agents.

One process, several processes, several servers

	One process	Several processes, one machine	Several servers
Memory store	`in_memory` (lost at exit) or anything durable	`sql` with SQLite	`sql` with PostgreSQL, `redis` or `mongodb`
Traces	The default	One after the other: the same working directory. At the same time: a `storage_path` each, `archive_index_url` and `archive_bodies_path` shared	A `storage_path` each, `archive_index_url` on the shared database, `archive_target: "object_storage"` (or a shared `archive_bodies_path`)
Payloads, if offloaded	The default	The default	`offload_target: "object_storage"`
Background tasks	`in_memory`	`sql` with SQLite	`sql` with PostgreSQL, `redis` or `mongodb`
Workspace files	Local	Local, one directory	S3 or R2

Why more processes: one process runs the runtime’s own work on one core, so it tops out near 15 runs a second of that work. Concurrent runs in one process mostly wait on the model, so it serves many at once; past that ceiling, add processes. A resumed or recovered run can land on any of them, provided they share the stores above.

Retention

Setting	Default	Removes
`agent_config["run_retention_days"]`	`30`	Finished run records (`completed`, `failed`, `blocked`, `cancelled`, `timeout`), counted from the run’s start. Waiting, interrupted and running runs are never removed
`telemetry_config["retention_days"]`	`7`	Finished traces, from the log and the archive
`telemetry_config["payload_retention_days"]`	`7`	Offloaded payloads no kept trace points to

None keeps everything. Each window is applied once, when an agent starts its first run; await agent.prune_runs() and await agent.prune_telemetry() apply it now. Session history is not pruned by age (windows and summaries keep it short), and neither is background run history. Details: how long a run’s evidence is kept.

Close what you open

You opened	Close it with	Closes
`MemoryRouter(...)`	`await router.close()`	MongoDB, Redis and SQL connections (a SQL pool is shared per database and closes with the last store using it)
`OmniCoreAgent(...)`	`await agent.cleanup()`	MCP connections and sub-agents; not the memory router you passed
`BackgroundAgentManager(...)`	`await manager.shutdown()`	The worker loop, the runs it is executing (their attempts are recorded), the task store

Whoever creates a router owns it: agent.cleanup() leaves it open, because other agents may share it. Build one per process and close it at shutdown, or close it in a finally, as ask.py does. Routers that name the same SQL database share one connection pool: closing one releases its share, and the pool closes with the last.

Options

Where	Key	Default	What it does
`MemoryRouter(...)`	store type	`"in_memory"`	`in_memory`, `sql`, `redis`, `mongodb`
`agent_config`	`run_lease_seconds`	`60`	How stale a running run’s heartbeat must be before another process may recover it
`agent_config`	`run_retention_days`	`30`	Days a finished run record is kept
`telemetry_config`	`storage`, `storage_path`	`"auto"`, the workspace	Where the trace log is
`telemetry_config`	`archive_index_url`, `archive_bodies_path`, `archive_target`	local	A shared archive
`telemetry_config`	`offload_large_payloads`, `offload_target`	`False`, `"workspace"`	Keep large values whole, and where
`BackgroundAgentManager`	`task_store`, `lease_seconds`	`"in_memory"`, `30`	The task store; how long a worker’s claim lasts

Every telemetry key: Telemetry settings. Every agent key: Agent settings. The manager: BackgroundAgentManager.

When things go wrong

Process two cannot find the run: LookupError: No run …

The two processes do not share a memory store. Most often the store is in memory, sometimes without you asking for it: MemoryRouter("sql") with no DATABASE_URL set falls back to an in-memory store, with a RuntimeWarning (SQL memory selected but DATABASE_URL is not set; using in_memory (nothing survives a restart)). Print the router to check:

MemoryRouter(type=sql, store=InMemoryStore)

With DATABASE_URL set it says store=DatabaseMessageStore. The same holds for redis without REDIS_URL and mongodb without MONGODB_URI.

ImportError: SQL database memory requires optional dependency 'sqlalchemy'

ImportError: SQL database memory requires optional dependency 'sqlalchemy'. Install it with: pip install 'omnicoreagent[postgres]'

Every sql store needs SQLAlchemy, SQLite included.

ValueError: Invalid memory store type

ValueError: Invalid memory store type: postgres. Use one of: in_memory, sql, redis, mongodb

PostgreSQL, MySQL and SQLite are all "sql"; DATABASE_URL picks the database. A background task store says the same in its own words: InvalidTaskStoreError: task_store must be 'in_memory', 'sql', 'redis', or 'mongodb'.

ValueError: telemetry archive_target must be local or object_storage

ValueError: telemetry archive_target must be local or object_storage

"s3" or "r2" is not a target: set "object_storage" and give the agent an S3 or R2 workspace.

The bodies never reach the bucket

archive_target: "object_storage" with a local workspace keeps the bodies on local disk, without an error. With telemetry_config["strict"] = True it is refused:

ValueError: telemetry archive_target='object_storage' requires an S3 or R2 workspace

offload_target: "object_storage" behaves the same way.

The run is found, but its trajectory is empty

get_run_trajectory shows trace_kept: False for a segment whose trace this process cannot read: another process wrote it to a different directory and nothing shares the archive, or it was pruned (retention_days). Share the archive, or run in the same directory.

Durable runs

Records, recovery after a crash, steering, and statuses.

Background agents

Tasks and schedules on a durable task store.

OmniServe

Serve the agent over HTTP, with the same stores.

Agent in a container

Package the agent with its keys and stores.

Memory

Session history, windows and summaries.

Telemetry settings

Every trace, archive and retention key.

Get Started

Build

Make It Safe

Run It

See and Improve

How It Works

Reference

HTTP API (OmniServe)

Releases

Stores and Scale

Stores and Scale

Pause in one process, resume in another

Which store holds what

The memory store

Traces

Offloaded payloads

Background tasks

One process, several processes, several servers

Retention

Close what you open

Options

When things go wrong

Next

Durable runs

Background agents

OmniServe

Agent in a container

Memory

Telemetry settings

​Stores and Scale

​Pause in one process, resume in another

​Which store holds what

​The memory store

​Traces

​Offloaded payloads

​Background tasks

​One process, several processes, several servers

​Retention

​Close what you open

​Options

​When things go wrong

​Next

Durable runs

Background agents

OmniServe

Agent in a container

Memory

Telemetry settings

Stores and Scale

Pause in one process, resume in another

Which store holds what

The memory store

Traces

Offloaded payloads

Background tasks

One process, several processes, several servers

Retention

Close what you open

Options

When things go wrong

Next