A man has been given a 12-month prison sentence for supplying the drug ecstasy to a friend at the Stereosonic music festival in Sydney, which may have caused her death.

Daniel Huynh, 26, from Punchbowl pleaded guilty to supplying two tablets to his friend Sylvia Choi, 25, at the festival at Homebush last year.

Ms Choi died after taking an MDMA tablet at the festival.

Magistrate Michelle Goodwin said comments Huynh left on mobile phone chat app WhatsApp in the lead up to the supply were incriminating.

"The language in those conversations show he was an organised and experienced person in drug supply," she said during his sentencing at Burwood court.

Huynh was sentenced to 12 months in jail with a non-parole period of six months.

But he has walked out of the court today, after he was later granted bail pending an appeal.

Huynh told friends to 'deny, deny, deny'

The comments he made in WhatsApp included references to the price of importing the drug.

He also told his friends to "deny, deny, deny" if arrested by police.

Sylvia Choi, 25, died after suffering an alleged overdose at the Stereosonic festival. ( Supplied: NSW Police )

Earlier, his barrister Carolyn Davenport SC said her client "is not to be sentenced for the death of Ms Choi".

She said it has not been established whether the drug he supplied caused her death, or something else she took at the dance party.

"He has expressed remorse at the death and the supply of drugs. He has pleaded guilty at the first opportunity," his barrister told the court.

She said a group of friends each ordered a specific amount of the drug and he was to make no profit.

The court also heard that the 26-year-old had lost his job and had been unable to properly grieve for his friend.

Ms Davenport had urged the magistrate to bring down a non-custodial sentence.