Caption translation

Live

Send your timed captions and a language. Get the same lines back translated, in the same order and with the same timings, ready to put on the video.

$0.00591 per 1,000 charactersFailed runs are not charged.

Caption translation

Input

Captions (SRT or VTT)segmentsThe timed caption lines, each with start, end (seconds) and text.

3 lines · 120 billed characters

Translate intotarget_languageThe language to translate into.

A language code: th, ja, zh-TW, pt-BR.

Captions' languageoptionalsource_languageThe captions' language; leave it out to detect it.

$0.00591 per started 1,000 characters.

120 billed characters120 billed characters

Example

Example outputMade with these inputs

1 00:00:00,200 --> 00:00:02,240 สวัสดีและยินดีต้อนรับสู่ร้านกาแฟของเรา 2 00:00:03,040 --> 00:00:05,160 วันนี้เรามีเค้กช็อกโกแลตสดใหม่ 3 00:00:05,880 --> 00:00:06,500 อยากลองชิมไหมครับ?

Language: th

Download SRT

How it works

01Send the captionsLines with start and end seconds, and a language such as th or ja.
02We translate themLine by line, short enough to read.
03Get the captionsBilled per 1,000 characters, known up front.

Call Caption translation from your code

One endpoint and one key, on the same balance as the playground. The request below is the example's own.

POSThttps://api.opennan.com/v1/captions/translations

Get an API key
Create a key in the console. It uses the same balance as the playground.
Create a key

Send your first request

The same request the playground sends. Set OPENNAN_KEY to your key.

curl https://api.opennan.com/v1/captions/translations \
  -H "Authorization: Bearer $OPENNAN_KEY" \
  -H "Content-Type: application/json" \
  -d '{"segments":[{"start":0.2,"end":2.24,"text":"Hello and welcome to our coffee shop."},{"start":3.04,"end":5.16,"text":"Today we have fresh chocolate cakes."},{"start":5.88,"end":6.5,"text":"Want to try them?"}],"target_language":"th","source_language":"en"}'

# Then poll until "status" is "succeeded" or "failed":
curl https://api.opennan.com/v1/tasks/<task id> -H "Authorization: Bearer $OPENNAN_KEY"

Poll the task
The call answers right away with a task id. Ask for the task until it finishes:
GEThttps://api.opennan.com/v1/tasks/{id}
queued
Waiting for a worker
running
Being made
succeeded
Done: outputs[].url holds the files
failed
Failed: you are not charged

Errors and how to fix them

401Missing or wrong key
Send the header Authorization: Bearer with a key from the console.
402Balance too low
Add credit in Billing, then send the same call again.
400A value is not accepted
Read error.message: it names the field. Use a value from the parameter table.
429Too many requests
Wait a few seconds and try again, waiting longer after each 429.

Add Opennan to your AI app

One install gives your AI every Opennan tool: video, images, chat, voice, music, sound effects, 3D, captions and dubbing. Pick your app and follow the steps.

MCP serverhttps://api.opennan.com/v1/mcp

Works in the Codex CLI, the Codex app and the Codex IDE extension: they share ~/.codex/config.toml. If the app or IDE does not see OPENNAN_KEY, use the config.toml option with your key in it. Codex asks before each tool call: approve it to go on.

Get an API key
Create a key in the console. It starts with sk- and uses the same balance as the website.
Create a key

Save your key as OPENNAN_KEY

# macOS / Linux (zsh shown; bash: ~/.bashrc)
echo 'export OPENNAN_KEY="sk-..."' >> ~/.zshrc
source ~/.zshrc

# Windows (PowerShell), then open a new terminal
setx OPENNAN_KEY "sk-..."

3
Install the Opennan plugin: the server plus a skill that teaches your AI to pick models, confirm prices and wait for results
```
codex plugin marketplace add Opennan/opennan-ai-plugin
codex plugin add opennan@opennan
```

Or add only the server

codex mcp add opennan --url https://api.opennan.com/v1/mcp --bearer-token-env-var OPENNAN_KEY

Or add this to ~/.codex/config.toml

[mcp_servers.opennan]
url = "https://api.opennan.com/v1/mcp"
http_headers = { Authorization = "Bearer sk-..." }

4
Check that opennan is listed
```
codex mcp list
```
Restart Codex, then ask for anything
“Make a 5 second video of rain on a neon street, a song to go with it and a poster image.”

Replace sk-... with your own key and keep it private: anyone who has it can spend your balance. Your app can list the tools before you add a key; making anything needs one.

This tool from your AI

Once Opennan is added, your AI calls this tool with arguments like these.

Tool: translate_captions
Example arguments: { "segments": [ { "start": 0.2, "end": 2.24, "text": "Hello and welcome to our coffee shop." }, { "start": 3.04, "end": 5.16, "text": "Today we have fresh chocolate cakes." }, { "start": 5.88, "end": 6.5, "text": "Want to try them?" } ], "target_language": "th", "source_language": "en" }