# Adapters

BeamWeaver keeps durable runtime dependencies explicit. Applications pass cache,
checkpoint, memory, vectorstore, and record-manager adapters into graphs or
agents; runtime code depends on behaviours, not Ecto modules.

Implemented local adapters include:

- `BeamWeaver.Checkpoint.ETS` and `BeamWeaver.Checkpoint.Ecto`
- `BeamWeaver.Cache.ETS` and `BeamWeaver.Cache.Ecto`
- `BeamWeaver.Memory.ETS` and `BeamWeaver.Memory.Ecto`
- `BeamWeaver.VectorStore.ETS` and `BeamWeaver.VectorStore.EctoPostgres`
- `BeamWeaver.Indexing.RecordManager.ETS`
- `BeamWeaver.Indexing.RecordManager.EctoPostgres`

Setup is explicit:

```elixir
defmodule MyApp.Repo.Migrations.AddBeamWeaverAdapters do
  use Ecto.Migration

  def up do
    BeamWeaver.Migrations.up(adapters: [:checkpoint, :memory, :cache])
  end

  def down do
    BeamWeaver.Migrations.down(adapters: [:cache, :memory, :checkpoint], version: 1)
  end
end
```

Normal runtime calls never create database tables automatically.

`BeamWeaver.Checkpoint.Ecto` supports PostgreSQL and SQLite through the same
Ecto query/write implementation. The application Repo selects the migration
dialect and transaction behavior. SQLite remains optional: applications that
choose it add `ecto_sqlite3`; PostgreSQL users are not forced to install it.
Other durable Ecto adapters retain the database support documented by their
own modules.

Durable adapters use `BeamWeaver.Serialization` by default. The default JSON
codec is type-tagged and allowlisted; encrypted checkpoint/store payloads can
opt in to `BeamWeaver.Serialization.Encrypted` with an explicit 32-byte
AES-256-GCM key:

```elixir
serialization: [
  codec: BeamWeaver.Serialization.Encrypted,
  encryption_key: :crypto.strong_rand_bytes(32)
]
```

Keep application database setup in migrations and release tasks. Runtime calls
should receive already-configured adapters rather than creating tables or
inferring database URLs.