Struct PostgresTaskStore 

pub struct PostgresTaskStore { /* private fields */ }

PostgreSQL-backed TaskStore.

Stores tasks as JSONB blobs in a tasks table. Suitable for multi-node production deployments that need shared persistence and horizontal scaling.

Schema

The store auto-creates the following table on first use:

CREATE TABLE IF NOT EXISTS tasks (
    id         TEXT PRIMARY KEY,
    context_id TEXT NOT NULL,
    state      TEXT NOT NULL,
    data       JSONB NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
);

list() returns tasks most-recently-updated first (spec §3.1.4), ordered by (updated_at DESC, id DESC) with a composite row-value cursor. The cursor carries updated_at as a UTC-normalized microsecond string, so pagination is stable regardless of the connection’s session time zone.

Implementations

impl PostgresTaskStore

pub async fn new(url: &str) -> Result<PostgresTaskStore, Error>

Opens a PostgreSQL connection pool and initializes the schema.

Errors

Returns an error if the database cannot be opened or the schema migration fails.

pub async fn with_migrations(url: &str) -> Result<PostgresTaskStore, Error>

Opens a PostgreSQL database with automatic schema migration.

Runs all pending migrations before returning the store. This is the recommended constructor for production deployments because it ensures the schema is always up to date without duplicating DDL statements.

Errors

Returns an error if the database cannot be opened or any migration fails.

pub async fn from_pool(pool: Pool<Postgres>) -> Result<PostgresTaskStore, Error>

Creates a store from an existing connection pool.

Errors

Returns an error if the schema migration fails.

Trait Implementations

impl Clone for PostgresTaskStore

fn clone(&self) -> PostgresTaskStore

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for PostgresTaskStore

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl TaskStore for PostgresTaskStore

fn save<'a>( &'a self, task: &'a Task, ) -> Pin<Box<dyn Future<Output = Result<(), A2aError>> + Send + 'a>>

Saves (creates or updates) a task.

fn get<'a>( &'a self, id: &'a TaskId, ) -> Pin<Box<dyn Future<Output = Result<Option<Task>, A2aError>> + Send + 'a>>

Retrieves a task by its ID, returning None if not found.

fn list<'a>( &'a self, params: &'a ListTasksParams, ) -> Pin<Box<dyn Future<Output = Result<TaskListResponse, A2aError>> + Send + 'a>>

Lists tasks matching the given filter parameters.

fn insert_if_absent<'a>( &'a self, task: &'a Task, ) -> Pin<Box<dyn Future<Output = Result<bool, A2aError>> + Send + 'a>>

Atomically inserts a task only if no task with the same ID exists.

fn delete<'a>( &'a self, id: &'a TaskId, ) -> Pin<Box<dyn Future<Output = Result<(), A2aError>> + Send + 'a>>

Deletes a task by its ID.

fn count<'a>( &'a self, ) -> Pin<Box<dyn Future<Output = Result<u64, A2aError>> + Send + 'a>>

Returns the total number of tasks in the store.