Castmagic
Turn a recording into a transcript, summary, clips, quotes, and reusable content assets
The core loop is buildable, but a dependable replacement becomes a real weekend or multi-day project. For Castmagic, turn a recording into a transcript, summary, clips, quotes, and reusable content assets. The hard boundary is large prompt library, integrations, team workflow, and hosted processing, plus audio infrastructure, distribution, and production polish.
Build verification: not recorded. How we judge buildability
What you give up
- large prompt library, integrations, team workflow, and hosted processing
- remote studio reliability
- licensed music libraries
- hosting distribution
- advanced mastering and support
Why people still pay
People still pay for Castmagic because creators pay to remove fragile audio plumbing and publishing chores from a release schedule. The recurring cost buys codec support, loudness standards, transcription, storage, feeds, analytics, and deliverability to directories, not just the visible interface.
Your build guide
The stack, security requirements, and agent rules for a focused replacement.
Before you start
- Runtime and tools: Python, FastAPI, SQLite, FFmpeg and a local faster-whisper worker with a React transcript editor.
- Before starting: An installed speech model, adequate local disk space and a recording made with participant permission; any optional hosted model needs a separately disclosed API key.
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.
Project rule — domain: Store Episode, TranscriptRevision, QuoteSpan, AssetTemplate and GeneratedAsset; direct quotations must match corrected source text and derivative assets retain the generating transcript version.
Project rule — scope and recovery: Human approval is required before publishing any derivative. Separate transcription from optional cloud generation, and do not equate an LLM's highlight score with predicted virality.
Project rule — acceptance: Correct a guest's name and remove an off-record segment; regeneration updates dependent drafts and excludes the removed material without changing the source file.
Project rule — delivery: document real setup commands and permissions; do not claim a build, accuracy level, performance result or security certification that has not been demonstrated.
Recommended skill: modern-python — structure the Python worker or explicitly optional read-only utility with pinned dependencies, typed boundaries and clear failure handling. Follow the maintainer's installation instructions and match its requirements to the chosen runtime.
Recommended skill: web-design-guidelines — review keyboard access, focus, validation, error recovery and the readable work/review interface or HTML report. Follow the maintainer's installation instructions and match its requirements to the chosen runtime.
Implementation plan
Phase 1
Pin the working slice and create its example input: Turn an imported interview into reviewed show notes, timestamped quotes and a small set of platform-specific draft assets. Confirm setup: An installed speech model, adequate local disk space and a recording made with participant permission; any optional hosted model needs a separately disclosed API key.
Phase 2
Implement persistence and write-time invariants before decorating the UI: Store Episode, TranscriptRevision, QuoteSpan, AssetTemplate and GeneratedAsset; direct quotations must match corrected source text and derivative assets retain the generating transcript version.
Phase 3
Connect the working view to real saved state. Keep original timing alongside corrected text. Speech recognition does not itself establish speaker identity; permit manual speaker labels. Show undecodable audio and uncertain passages without inventing words.
Phase 4
Expose the app-specific limits and recovery path in context: Human approval is required before publishing any derivative. Separate transcription from optional cloud generation, and do not equate an LLM's highlight score with predicted virality.
Phase 5
Walk through this concrete acceptance case and preserve its exported evidence: Correct a guest's name and remove an off-record segment; regeneration updates dependent drafts and excludes the removed material without changing the source file. Finish the README and backup/restore instructions; report unfinished capabilities explicitly.
Build the following focused alternative to Castmagic. This is a deliberately limited personal or small-team substitute, not parity with the paid service. WORKING SLICE Turn an imported interview into reviewed show notes, timestamped quotes and a small set of platform-specific draft assets. SETUP AND ARCHITECTURE Use Python, FastAPI, SQLite, FFmpeg and a local faster-whisper worker with a React transcript editor. Prerequisites: An installed speech model, adequate local disk space and a recording made with participant permission; any optional hosted model needs a separately disclosed API key. Before integrating anything, record actual versions and permissions, plus model files or provider limits only where used, in the README; make unavailable dependencies visible rather than simulating success. DOMAIN MODEL AND INVARIANTS Store Episode, TranscriptRevision, QuoteSpan, AssetTemplate and GeneratedAsset; direct quotations must match corrected source text and derivative assets retain the generating transcript version. IMPLEMENTATION CONTRACT Keep original timing alongside corrected text. Speech recognition does not itself establish speaker identity; permit manual speaker labels. Show undecodable audio and uncertain passages without inventing words. Provide an input/setup view, the main work view, and a review/export view appropriate to this workflow. Preserve the last saved state if a job or save fails. Include empty, loading, permission-denied, partial and retryable-error states. Log identifiers and error categories without secret values or unnecessary private content. APP-SPECIFIC BOUNDARY AND RECOVERY Human approval is required before publishing any derivative. Separate transcription from optional cloud generation, and do not equate an LLM's highlight score with predicted virality. ACCEPTANCE SCENARIO Correct a guest's name and remove an off-record segment; regeneration updates dependent drafts and excludes the removed material without changing the source file. Also reopen the app after an interrupted operation, confirm the saved record/export remains inspectable, and document the recovery action. These are implementation acceptance requirements, not a claim that this guide has been tested. DELIVERY Deliver a runnable repository with migrations or project-format versioning, a non-sensitive example, environment/permission setup, the exact manual acceptance steps, and a backup/export-and-restore walkthrough. Implement the working slice before optional integrations; list any deferred paid-product capabilities honestly. Do not add capabilities outside the working slice just to resemble the original product. PROJECT RULES FOR AGENTS.md Keep the domain invariants above executable at the write boundary. Propose scope changes before adding providers or permissions. Never fabricate source evidence, publish results, identity matches or successful delivery. Preserve user originals and require an explicit confirmation for destructive changes or external publication.
$ open in your agent (prompt prefilled, you press enter), copy the prompt or copy or download AGENTS.md
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Castmagic pricing
| plan | monthly | annual (per mo) | what you get |
|---|---|---|---|
| hobby | — | $19.92/workspace | 30 transcribed library hours total; 3 spaces; 50 GB storage; 3 seats; 10 GB/fileBilled $239/year; month-to-month price was not exposed on the current page. The supplied snapshot's $39/month headline no longer matches the live self-serve offer. |
| starter | — | $48.25/workspace | 100 transcribed library hours total; 10 spaces; 250 GB; 5 seats; API accessBilled $579/year; month-to-month price was not exposed on the current page. |
| team | — | $139.08/workspace | 400 transcribed library hours total; 25 spaces; 1 TB; 5 seats included; unlimited team sizeBilled $1,669/year; extra seats cost $159/year or $19/month. |
| business & scale | $699/workspace | — | Custom transcription volume, seats, storage, security and supportLive promotional starting price is $699/month with $999 struck through. |
free tierno permanent free tier; a trial is offered, but its numeric allowance is not published on the live pricing page
billingannual self-serve plans (advertised as 30% lower) plus monthly/custom Business & Scale
hidden costsLibrary-hour caps are cumulative rather than simple monthly allowances; more hours can be purchased, and Team seats beyond 5 cost $19/month or $159/year each.
pricing sources checked 2026-08-14 · pricing source ↗
Questions about Castmagic
Can you build your own Castmagic with AI?
Partly. The core loop is buildable, but a dependable replacement becomes a real weekend or multi-day project. For Castmagic, turn a recording into a transcript, summary, clips, quotes, and reusable content assets. The hard boundary is large prompt library, integrations, team workflow, and hosted processing, plus audio infrastructure, distribution, and production polish.
What does the Castmagic build prompt cover?
The prompt starts with this scope: Turn an imported interview into reviewed show notes, timestamped quotes and a small set of platform-specific draft assets. Full-product capabilities excluded from the comparison include: large prompt library, integrations, team workflow, and hosted processing; remote studio reliability; licensed music libraries. 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 Castmagic 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 Castmagic 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 Castmagic?
large prompt library, integrations, team workflow, and hosted processing; remote studio reliability; licensed music libraries; hosting distribution; advanced mastering and support. People still pay for Castmagic because creators pay to remove fragile audio plumbing and publishing chores from a release schedule. The recurring cost buys codec support, loudness standards, transcription, storage, feeds, analytics, and deliverability to directories, not just the visible interface.
What price is this guide comparing against?
The recorded Hobby plan is $19.92/mo (annual billing, per month), checked 2026-08-14. 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 Castmagic?
The prior-art section lists Audacity as starting points. Review their current scope, license and maintenance before adopting one.