PostgreSQL and array of custom type

One of the table I have looks like this

CREATE TABLE orders_suppliers_contacts
(
  supplier_id bigint NOT NULL,
  name character varying(64) NOT NULL,
  phone character varying(18),
  notes character varying(2000),
  last_modified timestamp without time zone NOT NULL,
  CONSTRAINT "FK_orders_suppliers_contacts" FOREIGN KEY (supplier_id)
      REFERENCES orders_suppliers (id) MATCH SIMPLE
      ON UPDATE CASCADE ON DELETE CASCADE
)

I need to change the field phone character varying into contacts contactinfo[] whose custom type is defined as

CREATE TYPE contactinfo AS (
    tag VARCHAR(8),
    "value" VARCHAR(64)
)

What would be the insert query for that?

INSERT INTO orders_suppliers_contacts VALUES
(1, 'John Smith', ???, null, NOW());

Also, once retrieved, the data is sent through a web API as JSON, will the column need to pass through a JSON function or is it already compatible? The required output (HTTP response) should be, something like

[{
  "supplier_id": 1,
  "name": "John Smith",
  "contact": [{"tag":..., "value":...}, ...],
  "notes":...,
  "last_modified":...
}, ...]

for a query such as SELECT * FROM orders_suppliers_contacts.