A durable ExAgent.Store backed by PostgreSQL, for resume across crashes and multiple nodes.

Snapshots are stored as JSON (the same strict serialization ExAgent.Store.ETS uses), never raw Erlang terms — so nothing non-serializable (pids, secrets, closures) can land in the database. The store is DB-free by default in the rest of exAgent: this module needs ecto_sql + postgrex, declared as optional dependencies that a host app adds when it wants a durable store.

Wiring

The store takes the host app's Ecto.Repo as its config (the host owns the database connection — exAgent never does):

# 1) add deps in your app:
#   {:ecto_sql, "~> 3.0"}, {:postgrex, "~> 0.19"}
# 2) create the table once (migration or at boot):
ExAgent.Store.Postgres.migrate(MyApp.Repo)
# 3) use it:
ExAgent.AgentSupervisor.start_agent(
  agent: agent_template,
  agent_id: "dm",
  store: {ExAgent.Store.Postgres, MyApp.Repo}
)

The snapshots table is exagent_snapshots by default; override it with {ExAgent.Store.Postgres, {MyApp.Repo, table: "my_snapshots"}}.

Why not own the database?

A library shouldn't own your connection pool, credentials or migrations. The repo comes from your app; exAgent only issues parameterized SQL against one table.