CREATE TABLE api_keys (
    id SERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    key_prefix VARCHAR(16) NOT NULL,
    key_hash TEXT NOT NULL UNIQUE,
    permissions_mask TEXT NOT NULL DEFAULT '0',
    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    expires_at TIMESTAMPTZ,
    last_used_at TIMESTAMPTZ
);

CREATE INDEX idx_api_keys_hash ON api_keys(key_hash);