telega_storage_postgres

PostgreSQL storage adapter for the Telega Telegram Bot Library.

Production-grade persistence for sessions and flows on PostgreSQL. Implements telega/storage.KeyValueStorage, so a single backend serves both sessions and flows.

Installation

gleam add telega_storage_postgres

Usage

import gleam/erlang/process
import gleam/option.{Some}
import pog
import telega/storage
import telega_storage_postgres as postgres

pub fn main() {
  let name = process.new_name("bot_db")
  let assert Ok(_) =
    pog.default_config(name)
    |> pog.database("bot")
    |> pog.user("postgres")
    |> pog.password(Some("postgres"))
    |> pog.start
  let conn = pog.named_connection(name)

  let assert Ok(Nil) = postgres.migrate(conn)
  let kv = postgres.new(conn)

  // Sessions — provide JSON encode/decode for your session type.
  let session_settings =
    storage.session_settings_from_storage(
      storage: kv,
      encode: encode_my_session,
      decode: my_session_decoder(),
      default: fn() { default_session() },
    )

  // Flows — the full instance is serialized for you.
  let flow_storage = storage.flow_storage_from_storage(kv)

  // ... wire `session_settings` and `flow_storage` into your bot.
}

Schema

migrate creates this table (use migrate_table / new_with_table for a custom name):

CREATE TABLE IF NOT EXISTS telega_storage (
  key        TEXT PRIMARY KEY,
  value      TEXT NOT NULL,
  expires_at BIGINT  -- epoch ms; NULL = never
);

TTL is enforced lazily — expired rows are dropped on access (get/scan). For eager cleanup you may run a periodic DELETE FROM telega_storage WHERE expires_at IS NOT NULL AND expires_at < <now_ms>.

Testing

gleam test

Integration tests connect to localhost database telega_test (user/password postgres). They are skipped automatically when no database is reachable.