Synthesia
Connect Synthesia to make AI avatar videos from a script or template, dub and translate them, and manage your videos and webhooks.
You paste one value into PopMCP: a Synthesia API key, made under Developers in Synthesia with the right scopes ticked.
Paid plan required before this connector works
No one reviews you, but making videos through the API needs a Pro plan or above, because your plan decides which scopes a key can have. Dubbing through the Localization API works on every plan.
- Typical wait
- None. A plan change applies as soon as you make it.
- Cost
- Synthesia's Pro plan, shown at $89 a month or $59 a month billed yearly in October 2026, plus the credit each video and dub uses. PopMCP adds nothing to this.
- Blocked until approved
- Videos, templates, webhooks, uploads and translations, which all need the Legacy (v2) scope. Audit logs and XLIFF need Enterprise.
- Works meanwhile
- On any plan, make a key with Localization (write) and connect it. Your AI can then read your credit balance and dub videos while the workspace has credit.
Where to apply: No application. In Synthesia open Billing & Usage and upgrade, then tick Legacy (v2) on your key under Developers, then API keys.
- Test videos are free with a watermark and limited to 30 a day, and PopMCP's video tools use them unless told otherwise.
- Keys expire on the date you pick, 30 days by default, and the connection stops when they do. Pick a longer time or Never.
- If the person who made the key leaves the workspace, Synthesia disables the key.
- Lip-sync costs extra credit and needs a plan that includes it.
- Setup time
- 2 min
- Auth
- API credentials
Before you begin
- A Synthesia account. Making videos through the API needs a Pro plan or above. Dubbing through the Localization API works on every plan
- Credit in the workspace, if your AI will make real videos or dub them. Free test videos and reading your videos need none
Get your credentials
Open Developers in Synthesia
Sign in to Synthesia and select Developers in the sidebar, then the API keys tab. A key belongs to the workspace you are in, so switch to the right workspace first. To work in another one later, connect it with its own key.
Make a key for PopMCP
Select New API key and name it PopMCP. Under Scopes, tick Legacy (v2) for videos, templates, webhooks and uploads, and Localization (write) for dubbing. Tick Interactive Avatars (write) if you use live avatars. Your plan decides which ones you can tick. Under Expires, pick a longer time or Never: the default is 30 days, and your connection stops when the key expires. Then select Create API key.
New API key
Choose what this key can reach, and when it expires.
This view is a simplified sketch: the labels on your page may differ slightly.
Copy the key right away
Copy the key as soon as it appears. Synthesia only shows it in full once. If you lose it, delete it and make a new one.
Paste the key into PopMCP
In PopMCP, paste the key into API key and connect. PopMCP tries your videos, your dubbing languages and your credit balance with free reads, and tells you if a scope is missing. New connections start read-only, so your AI can look at your videos and templates but cannot make anything or spend credit until an owner or admin allows write actions.
Connect in PopMCP
Open your workspace, choose Synthesia in the marketplace, and fill in the connect dialog:
| Field | What to enter |
|---|---|
| API keysecret | In Synthesia open Developers, then API keys, and choose New API key. Copy it right away, because it is only shown once. Stored encrypted and used only on our servers.Encrypted with AES-256-GCM on save and never shown again. |
PopMCP verifies the credential against Synthesia immediately. On success the connection flips to Verified and its MCP tools are provisioned.
Verify it worked
PopMCP marks the Synthesia connection Verified and notes any scope the key is missing. Asking the AI how many credits you have left, then to list your videos, returns real results at no cost.
Troubleshooting
"Synthesia did not accept this API key..."
Why: The key was copied incompletely, or it has been disabled or deleted. Synthesia also disables a key when the person who made it leaves the workspace.
Fix: Open Developers, then API keys, in Synthesia and make a new key. It is only shown in full once.
"This Synthesia API key has expired..."
Why: Keys expire on the date chosen when they were made. The default is 30 days.
Fix: Make a new key with a longer time or Never, and connect it in PopMCP.
"This key cannot reach videos or dubbing..."
Why: The key has neither the Legacy (v2) nor the Localization scope, or your plan does not allow them.
Fix: Under Developers, then API keys, choose Edit key on this key and tick the scopes. Legacy (v2) needs a Pro plan or above. You do not need a new key for this.
Videos answer 403, but dubbing works
Why: The key has a Localization scope but not Legacy (v2). The two are separate: neither covers the other.
Fix: Tick Legacy (v2) under Edit key. Asking the AI to check the key's access shows which parts it can reach.
The AI says it cannot make a video
Why: The connection is read-only, which is how every new connection starts. Making a video can spend credit, so it counts as a write.
Fix: Have an owner or admin allow write actions on the connection in PopMCP.
The video has a watermark
Why: PopMCP's video tools make a free test unless told otherwise. Tests carry a watermark and are limited to 30 a day.
Fix: Once you are happy with it, ask the AI to make the final version without test mode. That one spends credit.
A video stays in progress for a long time
Why: Rendering takes a few minutes, and a finished video stays in progress while it passes moderation review.
Fix: Ask the AI to check on it again. It keeps the same video, so nothing is started twice.
A download link no longer opens
Why: Synthesia's download links are time-limited.
Fix: Ask the AI to get the video again. A fresh read gives a new link.