How Hookletter works

Hookletter is an app for ChatGPT, Claude and Grok Bot that makes a personal song for someone. You tell the assistant who it's for and what happened; together you write the lyrics; Hookletter keeps the song, makes the music with ElevenLabs' Eleven Music model and gives you a private page to listen, download and send it.

The flow

Start: say the occasion, the person's first name and what to sing about, in Turkish or English.
Lyrics: the assistant reads Hookletter's lyric rules (sections, line counts, syllables and rhyme, original words only) and writes a draft; you change anything.
Sound: pick a genre, up to four instruments, a singer (female, male, duet or choir; low, mid or high; warm, bright or raspy), a tempo and a length from 1:30 to 3:00.
Preview: hear a 25-second chorus first. Before the first song, the card asks you to accept the music terms once.
Full song: made in a minute or two. Change one part at a time; every change is a new version and the old ones stay.
Send: a private link plays one version with your note. Your own song page has MP3 and WAV downloads and the free release kit.

What each tool does

Tool	What it does	Changes
`start_song`	Starts a song: occasion, first name, details, language, mood, and optionally genre, instruments, singer, tempo and length.	Adds a song
`get_song_brief`	Returns the song so far and the lyric rules the assistant writes to.	Read-only
`save_lyrics`	Stores the title and tagged sections as a new lyrics version after checking them.	Adds a version
`change_sound`	Changes genre, instruments, tempo, singer, mood or length for the next preview or version.	Overwrites settings
`make_hook`	Makes a 30-second chorus preview.	Uses today's allowance
`make_song`	Makes the full song as a new numbered version.	Uses today's allowance
`redo_section`	Makes one section again from a note and keeps the rest of the song.	Uses today's allowance
`show_song`	Shows a song (lyrics, sound, versions, song page) or lists your songs.	Read-only
`share_song`	Returns a private link to one version, with an optional from line and note.	Adds a link
`delete_song`	Deletes the song, its lyrics, audio and links at once.	Deletes
`get_render, accept_terms`	Used by the card only: progress checks and the one-time terms acceptance.	Card only

Example prompts

“Make a song for my mum's 60th birthday: her garden, her cookies, and how she always tells us not to get cold.”
“Annemin doğum günü için Türkçe, neşeli bir şarkı yap; bağlama ve darbuka olsun.”
“Write a funny song about our group chat's failed camping trip, pop punk, male voice.”
“Make the chorus happier and add strings.” · “Send version 2 to Ayşe with the note ‘Happy birthday, Mum’.”

Limits

Lyrics in Turkish or English; up to 12 sections; length 1:30 to 3:00.
No artist names, song titles, existing lyrics, covers or imitations of real singers; a style request is described by genre, era and instruments instead.
No voice uploads. A first name at most; no contact details.
Making music uses a daily allowance shared by everyone; when the studio is full, your song stays saved for the next day.
Until launch, making music is open to invited testers: an access code goes in the first message (“…access code HOOKLETTER-…”) or in the card's code box. Starting songs and writing lyrics needs no code.
For adults, 18 and over.
Songs are deleted 12 months after their last change, or at once on request.

Connect

ChatGPT: coming to the ChatGPT app directory. Developer mode MCP URL: https://hookletter.ambientapp.ai/mcp
Claude (paid plans, custom connector): Customize → Connectors → Add custom connector → https://hookletter.ambientapp.ai/mcp/claude, no authentication.
Grok Bot: “Add this MCP server: https://hookletter.ambientapp.ai/mcp/grok”, then attach it with @.

Troubleshooting

“Today's song studio is full.” The daily allowance is used up; ask again tomorrow. Nothing is lost.
“The studio opens soon.” Making music is invite-only until launch; with an access code, type it in the card's code box or say it in the chat.
No sound in the card. Some hosts block audio in cards: use the Song page button.
A name is mispronounced. Spell it as it sounds and redo that part.
The card asks for the terms again. The terms changed; accept the new version once.
Grok Bot: the chips can't post a chat message there, so they change the sound directly; type your request in the chat for anything else.