Fitbod
Build moderate workout plans from user-selected equipment and recovery notes
The core loop is buildable, but a dependable replacement becomes a real weekend or multi-day project. For Fitbod, build moderate workout plans from user-selected equipment and recovery notes. The hard boundary is exercise library, adaptive programming, mobile capture, wearables, and coaching models, plus hardware data, content, coaching, and trust.
Build verification: not recorded. How we judge buildability
What you give up
- exercise library, adaptive programming, mobile capture, wearables, and coaching models
- wearable hardware data
- coach network
- clinical validation
- large content library and social network
Why people still pay
People still pay for Fitbod because people pay for polished mobile capture, trusted content, hardware integration, and coaching rather than the basic logbook. The recurring cost buys sensor permissions, data quality, notifications, safety language, accessibility, sync, privacy, content review, and support, not just the visible interface.
Your build guide
The stack, security requirements, and agent rules for a focused replacement.
Before you start
- A supported Node release, a writable local data directory and a separate backup location. Bind to localhost; remote use requires authentication and HTTPS first.
- Implementation components: Node.js, TypeScript and Express with server-rendered HTML and small browser modules. SQLite through better-sqlite3 with migrations, prepared statements and a single background worker.
- Scope boundary: No diagnosis, guaranteed results, prescriptive rehabilitation or validated recovery algorithm.
Use these project rules and optional skill references alongside the prompt. Review each skill before adding it to your agent; the AGENTS.md export includes the same guidance.
Optional external skill: web-design-guidelines — Review web interfaces for accessibility, keyboard focus, forms, navigation and interaction quality. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
Optional external skill: sharp-edges — Review security-sensitive APIs and configuration for dangerous defaults and easy-to-misuse interfaces. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
Project rule — data model: exercise catalog, selected equipment, user-authored routines, performed sets, effort notes and history
Project rule — preserve this invariant: A heuristic muscle-recovery display is not a medical assessment; pain or injury notes do not trigger intensified exercise recommendations.
Project rule — acceptance evidence: Exclude a piece of equipment and remove dependent exercise suggestions; a missed workout remains missing rather than appearing as a completed session.
Implementation plan
Phase 1
Scope and fixtures. Implement this bounded workflow: Choose available equipment, assemble a moderate routine from reviewed exercises and log sets with a rest timer. Suggest a next session using transparent user-configured rules and display the rationale for each suggestion. Record prerequisites, select representative user-owned fixtures and document the unsupported features: No diagnosis, guaranteed results, prescriptive rehabilitation or validated recovery algorithm.
Phase 2
Durable model. Model exercise catalog, selected equipment, user-authored routines, performed sets, effort notes and history Add migrations or a versioned document format, explicit validation, stable IDs and a visible import-error report. Preserve this rule: A heuristic muscle-recovery display is not a medical assessment; pain or injury notes do not trigger intensified exercise recommendations.
Phase 3
Complete the first useful path. Implement the workflow's input, review and output interface, with clear controls and explicit empty/error states. Use short SQLite transactions and persist job state before starting work. Give retries stable operation IDs; report incomplete or unknown results instead of silently repeating them.
Phase 4
Permissions and integration failure. Reject unexpected origins and unbounded request bodies even on localhost. Keep credentials outside the database export and redact sensitive text from logs. Request integration credentials and permissions only for the enabled feature; show a disconnected state instead of mock results.
Phase 5
Portable handoff. Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data. Include setup, operating limits, fixture walkthrough and shutdown/restart instructions in the README.
Phase 6
Acceptance scenarios. Exclude a piece of equipment and remove dependent exercise suggestions; a missed workout remains missing rather than appearing as a completed session. Repeat the workflow after restart and with a denied permission or unavailable dependency; show recoverable failure rather than a success placeholder.
WORKING SLICE Choose available equipment, assemble a moderate routine from reviewed exercises and log sets with a rest timer. Suggest a next session using transparent user-configured rules and display the rationale for each suggestion. Build this scoped Fitbod-inspired workflow with a documented data model and visible failure states. Architecture - Node.js, TypeScript and Express with server-rendered HTML and small browser modules. - SQLite through better-sqlite3 with migrations, prepared statements and a single background worker. Prerequisites and limits A supported Node release, a writable local data directory and a separate backup location. Bind to localhost; remote use requires authentication and HTTPS first. Outside this release: No diagnosis, guaranteed results, prescriptive rehabilitation or validated recovery algorithm. Data model and correctness exercise catalog, selected equipment, user-authored routines, performed sets, effort notes and history Invariant: A heuristic muscle-recovery display is not a medical assessment; pain or injury notes do not trigger intensified exercise recommendations. Use short SQLite transactions and persist job state before starting work. Give retries stable operation IDs; report incomplete or unknown results instead of silently repeating them. Security and privacy Reject unexpected origins and unbounded request bodies even on localhost. Keep credentials outside the database export and redact sensitive text from logs. Recovery and export Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data. Implementation order 1. Phase 1 — Scope and fixtures. Implement this bounded workflow: Choose available equipment, assemble a moderate routine from reviewed exercises and log sets with a rest timer. Suggest a next session using transparent user-configured rules and display the rationale for each suggestion. Record prerequisites, select representative user-owned fixtures and document the unsupported features: No diagnosis, guaranteed results, prescriptive rehabilitation or validated recovery algorithm. 2. Phase 2 — Durable model. Model exercise catalog, selected equipment, user-authored routines, performed sets, effort notes and history Add migrations or a versioned document format, explicit validation, stable IDs and a visible import-error report. Preserve this rule: A heuristic muscle-recovery display is not a medical assessment; pain or injury notes do not trigger intensified exercise recommendations. 3. Phase 3 — Complete the first useful path. Implement the workflow's input, review and output interface, with clear controls and explicit empty/error states. Use short SQLite transactions and persist job state before starting work. Give retries stable operation IDs; report incomplete or unknown results instead of silently repeating them. 4. Phase 4 — Permissions and integration failure. Reject unexpected origins and unbounded request bodies even on localhost. Keep credentials outside the database export and redact sensitive text from logs. Request integration credentials and permissions only for the enabled feature; show a disconnected state instead of mock results. 5. Phase 5 — Portable handoff. Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data. Include setup, operating limits, fixture walkthrough and shutdown/restart instructions in the README. 6. Phase 6 — Acceptance scenarios. Exclude a piece of equipment and remove dependent exercise suggestions; a missed workout remains missing rather than appearing as a completed session. Repeat the workflow after restart and with a denied permission or unavailable dependency; show recoverable failure rather than a success placeholder. Acceptance Exclude a piece of equipment and remove dependent exercise suggestions; a missed workout remains missing rather than appearing as a completed session. Use real source data or clearly labeled fixtures. Explain unsupported input and provider failures; do not fabricate analytics, delivery receipts, accuracy claims or security guarantees. Optional agent guidance Optional external skill: [web-design-guidelines](https://github.com/vercel-labs/agent-skills/blob/main/skills/web-design-guidelines/SKILL.md) — Review web interfaces for accessibility, keyboard focus, forms, navigation and interaction quality. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission. Optional external skill: [sharp-edges](https://github.com/trailofbits/skills/blob/main/plugins/sharp-edges/skills/sharp-edges/SKILL.md) — Review security-sensitive APIs and configuration for dangerous defaults and easy-to-misuse interfaces. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission. Project rule — data model: exercise catalog, selected equipment, user-authored routines, performed sets, effort notes and history Project rule — preserve this invariant: A heuristic muscle-recovery display is not a medical assessment; pain or injury notes do not trigger intensified exercise recommendations. Project rule — acceptance evidence: Exclude a piece of equipment and remove dependent exercise suggestions; a missed workout remains missing rather than appearing as a completed session.
$ open in your agent (prompt prefilled, you press enter), copy the prompt or copy or download AGENTS.md
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Fitbod pricing
| plan | monthly | annual (per mo) | what you get |
|---|---|---|---|
| fitbod | $15.99/user | $8/user | Full adaptive workouts and access to 1,500+ exercises; 7-day trial$95.99 billed annually. |
| family duo | — | — | 2 members; annual-only family subscriptionCurrent USD price was not exposed on Fitbod's public support pages. |
| family | — | — | Up to 5 members; annual-only family subscriptionCurrent USD price was not exposed on Fitbod's public support pages. |
free tierno permanent free tier; 7-day trial, after which a non-subscriber can view history but can log 0 new workouts
billingindividual monthly + annual; Family Duo and Family are annual only
hidden costsThe trial converts to a paid subscription unless canceled through the purchase channel. Family pricing is shown only inside eligible checkout flows, and occasional Lifetime promotions are not a standing tier.
pricing sources checked 2026-08-14 · pricing source ↗
Questions about Fitbod
Can you build your own Fitbod with AI?
Partly. The core loop is buildable, but a dependable replacement becomes a real weekend or multi-day project. For Fitbod, build moderate workout plans from user-selected equipment and recovery notes. The hard boundary is exercise library, adaptive programming, mobile capture, wearables, and coaching models, plus hardware data, content, coaching, and trust.
What does the Fitbod build prompt cover?
The prompt starts with this scope: Choose available equipment, assemble a moderate routine from reviewed exercises and log sets with a rest timer. Suggest a next session using transparent user-configured rules and display the rationale for each suggestion. Full-product capabilities excluded from the comparison include: exercise library, adaptive programming, mobile capture, wearables, and coaching models; wearable hardware data; coach network. Follow the implementation plan and its prerequisites before expanding the build.
How do I use the prompt, AGENTS.md and agent skills?
Start with the Fitbod prerequisites and stack, then copy the prompt into your coding agent. Save the project rules as AGENTS.md in the project root. Linked skills are optional packages or source instructions for specific tasks; review their current contents and install only those matching the chosen stack. A skill does not supply API credentials or verify the finished app.
How long will this Fitbod project take?
The catalogue estimate is multi-day for the limited scope. Setup, integration approvals, debugging, deployment and ongoing maintenance can add time. This is an estimate, not a delivery guarantee.
What would I give up by replacing Fitbod?
exercise library, adaptive programming, mobile capture, wearables, and coaching models; wearable hardware data; coach network; clinical validation; large content library and social network. People still pay for Fitbod because people pay for polished mobile capture, trusted content, hardware integration, and coaching rather than the basic logbook. The recurring cost buys sensor permissions, data quality, notifications, safety language, accessibility, sync, privacy, content review, and support, not just the visible interface.
What price is this guide comparing against?
The recorded Fitbod plan is $15.99/mo (monthly), checked 2026-07-31. Check the linked pricing source before buying. Building your own also has hosting, API and maintenance costs; the recorded amount is not a guaranteed saving.
What can I use instead of building Fitbod?
Workout.cool: Pick equipment and muscles; it makes a routine without pretending to know your soul. wger: Plans, progression and recovery notes in one open-source gym; the recommendations are less clairvoyant. Check each option's license, hosting needs and feature limits.