A plan made for them
A multi-week plan from each member’s goal, training days, session length, equipment and limits, sent in their own words.
AI workout API
A personal plan for every member, one API call away.
You build a fitness app. Your members want a workout plan made for them, and your team has other things to ship. Budy’s AI workout API builds each plan from the member’s goal, training days and equipment. Five calls take an empty test account to a plan built from your own exercises.
From a member’s goal to today’s workout
- Ask for the plan
POST /v1/members/{memberId}/plans - Hear it is ready
plan.ready - Show today’s workout
GET /v1/members/{memberId}/today
Run a gym or a club? See the AI coach for gyms
Want meals, a coach or a whole branded app too? See the AI fitness API and white-label apps
What your members get
A plan that reads like a coach wrote it for one person, because it was built from what that person told your app.
Today’s workout, ready to follow
Sets, reps, weight, rest and alternatives for every exercise, with logging, skips and swaps.
A plan that changes when they ask
A member says what felt too hard or which exercise doesn’t suit them, and the rest of the phase is rebuilt.
The next phase arrives by itself
Later phases and the next plan follow by themselves, so no member runs out of plan.
From a member’s goal to a plan in one call
REST and JSON. Your server sends a secret key, and your app a short-lived member token. The plan is built in the background, usually in a few minutes.
- Goals and limits go in the member’s own words
- Plans can be written in other languages
- Separate live and test environments
- Safe retries with an Idempotency-Key
- Signed webhooks, or poll the job
Say who the member is and ask for the plan
POST /v1/members/fm-8812/plans Authorization: Bearer bdy_test_… Idempotency-Key: 9a7c3f10-52de-4b8a-a1c6-3e0f7d2b4c11 Content-Type: application/json { "goal": "Get stronger and lose 4 kg before summer", "sex": "female", "birthYear": 1994, "heightCm": 168, "weightKg": 66, "days": ["MON", "WED", "SAT"], "minutesPerSession": 45, "places": [ { "name": "Home", "kind": "home", "equipment": ["Dumbbells 2–10 kg", "Mat"] } ], "limits": "Lower back gets sore after deadlifts" }Budy answers at once with a job
202 Accepted Location: /v1/jobs/job_… { "id": "job_…", "type": "plan", "status": "running", "memberId": "fm-8812", "createdAt": "2026-11-23T09:41:07Z", "finishedAt": null, "result": null, "error": null }Read the job, or wait for the plan.ready webhook
GET /v1/jobs/job_… Authorization: Bearer bdy_test_… { "id": "job_…", "type": "plan", "status": "succeeded", "memberId": "fm-8812", "createdAt": "2026-11-23T09:41:07Z", "finishedAt": "2026-11-23T09:46:52Z", "result": { "planId": "cmh2x…" }, "error": null }Your app shows today’s workout
POST /v1/members/fm-8812/tokens Authorization: Bearer bdy_test_… GET /v1/members/me/today Authorization: Bearer eyJ…
Everything else your app can call
Take the workouts alone, or add the rest. AI work answers with a job, like the plan above.
| Feature | What it does for a member | Calls |
|---|---|---|
| Plans and updates | Three plan options to choose from, the plan and its schedule, logging, swaps, and the rest of a phase rebuilt from the member’s feedback. |
|
| Meal plans | A day’s meals around the member’s targets and tastes, each with its recipe, and ideas for the next meal. |
|
| Meal photo | Calories and macros from a photo of a meal. |
|
| Coach | A chat that knows the member’s plan and proposes changes, which the member applies or undoes. |
|
| Supplements and blood test | A monthly supplement assessment, and biological age from a blood test report. |
|
| Body composition | Reads a body composition sheet, and turns progress photos into a short summary that plans and the coach use. |
|
| Equipment recognition | Names the gear in photos of a gym or a home, so plans are built around what is really there. |
|
| Voice | Voice-guided workouts in Budy’s coach voices, or in your own coach’s voice with their consent. |
|
What you control
The AI should train people the way your product does. You set this up in the partner console or through the API.
Your own exercise library
Plans are built from your exercises and come back with your own videos. Add them one at a time, 100 in a call, or import up to 10,000 from a file. Budy’s 4,800+ exercises are available for a small monthly fee, with names and equipment. Videos stay yours to add.
PUT /v1/exercises/{exerciseRef}
POST /v1/exercises/batch
POST /v1/exercises/importsCoaching rules in plain words
Write rules like “Members over 60 never do jumping exercises.” The AI reads them with each member’s profile whenever it builds or changes a plan.
PUT /v1/coaching-rules/{ruleId}Your coach’s name
Name the coach and set its tone. It speaks as your coach and never mentions Budy.
PUT /v1/coaching-profileTiers and limits
Sell your own tiers. You decide how many plans, meal ideas and coach chats each one includes, and put each member on one.
PUT /v1/members/{memberId}
GET /v1/featuresYour own AI key
Run on your own OpenAI key and pay the provider directly. Budy can also open its own keys to you, billed at cost.
The AI behind these calls already keeps people training.
It is the same AI that runs the Budy app on iPhone, Apple Watch and Android. This is what keeps Budy’s own members training, and the stories below are theirs.
- Bad weeks stop ending the streak.
- Short on time, stuck at home or short on sleep? The session changes to fit, and the habit survives the week.
- Starting takes one tap.
- Your next workout is planned before you open the app. No deciding, no searching, no talking yourself out of it.
- You can see it working.
- Finished weeks, heavier lifts and new records show up as you go, and that is what keeps people coming back.
4 months in
Hanz
Wanted to lose weight, but working out what to do at the gym kept getting in the way.
The longest gym streak so far. Knowing what to do next made the routine easier to follow.
5 months in
Elina
Started with significant back pain that made sitting and walking uncomfortable.
Able to move more freely.
7 months in
Melona
Wanted to build muscle and couldn’t find a plan that felt right.
Much more confident about training.
Shared with Budy by customers, summarized and published with permission. Individual experiences vary. Elina’s health outcome is self-reported; other care during those months has not been verified. Budy provides fitness guidance, not treatment or rehabilitation. See MedlinePlus on when to seek care for back pain.
Where your members’ data lives, and what you pay
Your members’ data
- Stored in the EU
- Member data is stored with AWS in Frankfurt. AI requests go to the AI provider, which can process them outside the EU.
- Kept apart
- Each partner has its own live database and its own test database. A test key can never reach a live member.
- Not used for training
- Budy does not use your members’ data to train AI models, and it never reaches another partner or the Budy app.
- Export and erase
- One API call exports everything held on a member. Another erases it.
GET /v1/members/{memberId}/exportDELETE /v1/members/{memberId}
What you pay
From €300 a month
A monthly fee, set by the package you choose and how many active members you have. Nutrition starts at €300 a month for up to 1,000 active members. AI usage is on top: use your own AI key and pay your provider, or use Budy’s keys at cost.
- Test members are never billed
- Live keys follow a go-live review and a signed data processing agreement
How to start
Ask for test keys
Email [email protected] with your app and what you want to add.
Build on test keys
Add your exercises and rules in the console and build with up to 25 test members.
Go-live review
We check your setup together and sign the data processing agreement.
Ship it
Switch to live keys, and add products as you grow.
Common questions from app teams
What is an AI workout API?
An AI workout API lets your app ask for a workout plan and get one back, built by AI for one person. Budy’s API builds a multi-week plan from a member’s goal, training days, session length, equipment and limits, then serves today’s workout with sets, reps, weight, rest and alternatives. It is the same AI that runs the Budy app.
Is this an AI workout generator API or an AI personal trainer API?
Both. The workout calls generate plans and change them from a member’s feedback. The coach calls add a chat that knows the member’s plan and proposes changes, which the member approves. You can take the workouts alone and add the coach later.
How long does it take to generate a workout plan?
Plans are built in the background, usually in a few minutes. The call answers at once with a job, and a signed webhook tells your server when the plan is ready. You can also poll the job.
Can plans use our own exercises and videos?
Yes. Plans are built from your own exercise library, and each exercise comes back with your own media. Budy’s library of 4,800+ exercises is also available for a small monthly fee, with names and equipment. Videos stay yours to add.
Can plans be written in other languages?
Yes. Send the member’s language with their profile, and plans can be written in other languages.
Do we need our own AI account?
By default, yes. Add your OpenAI key in the partner console and your provider bills you directly. Budy can also open its own keys to your account, billed to you at cost.
Is there a test environment?
Yes. Every partner has a test environment with its own keys and its own database, and a test key can never reach a live member. You build with up to 25 test members, and test members are never billed.
Where is member data stored, and is it used to train AI?
Member data is stored in the EU, in separate live and test databases for your account. AI requests go to the AI provider, which can process them outside the EU. Budy does not use your members’ data to train AI models. One call exports everything held on a member, and another erases it.
How much does the AI workout API cost?
Packages start from €300 a month, for Nutrition with up to 1,000 active members. Your fee depends on the package you choose and your number of active members, plus AI usage. Ask the Budy team for a proposal.
We run a gym, not an app. Is this for us?
This page is for the team that builds the app. If you run a gym, start with the AI coach for gyms: it covers the gym partner program, a branded app, and the API with your app vendor.
Ship the plan your members asked for.
Tell us about your app and what you want to add. Email [email protected] and the Budy team will reply.
