Rendobar covers both sides of media work.
Transform what you have. Run any FFmpeg command against video, audio or images the way you would write it locally. Inspect a file and get a normalized summary plus the full ffprobe report. Compose video from a declarative JSON timeline. Compress to a target size or quality, where the encoder searches candidate encodes and returns the smallest file that clears the bar. Burn in subtitles from SRT, VTT or ASS, or let it transcribe when none is given.
Generate what you do not. Create an image from a text prompt on hosted open-weight diffusion models. Edit up to four reference images from a written instruction, no masks and no coordinates. Upscale on a one-step diffusion restoration model that reconstructs detail rather than only sharpening. The same model-backed layer drives the transcription and keyword highlighting behind animated captions, so this is not an image-only capability.
The job list grows over time, so this README names families rather than types. list_job_types reads the current set live from the registry on every call.
Published to npm as @rendobar/mcp and to the official MCP Registry as com.rendobar/mcp.
Without it
You: Mute the first 3 seconds of
intro.mp4.
The agent tells you to install FFmpeg. Then you go looking for how to gate a
filter on a timestamp, land on volume=enable='lt(t,3)', and lose another few
minutes to quote escaping in your shell. Nobody remembers that syntax, which is
the problem.
With it
You: Mute the first 3 seconds of
intro.mp4.
upload_file { "path": "~/clips/intro.mp4" }
// → { "downloadUrl": "https://cdn.rendobar.com/u/abc123/intro.mp4", "sizeBytes": 4821004 }
submit_job { "type": "ffmpeg",
"inputs": { "intro.mp4": "https://cdn.rendobar.com/u/abc123/intro.mp4" },
"params": { "command": "-i intro.mp4 -af \"volume=enable='lt(t,3)':volume=0\" -c:v copy out.mp4" } }
// → { "jobId": "job_9f2a", "status": "waiting" }
get_job { "jobId": "job_9f2a", "wait": true }
// → complete · $0.01 · https://cdn.rendobar.com/o/job_9f2a/out.mp4
The agent writes the filter. Rendobar runs it. Nothing gets installed on your
machine, and -c:v copy means the video stream is never re-encoded.
Two more things to ask for
Hit a size budget.
You: Get
demo.movunder 25 MB so I can email it.
upload_file { "path": "~/recordings/demo.mov" }
// → { "downloadUrl": "https://cdn.rendobar.com/u/7c1e/demo.mov", "sizeBytes": 251658240 }
submit_job { "type": "compress.target",
"inputs": { "source": "https://cdn.rendobar.com/u/7c1e/demo.mov" },
"params": { "for": "web", "target": { "maxSize": "25MB" } } }
// → { "jobId": "job_4b8d", "status": "waiting" }
get_job { "jobId": "job_4b8d", "wait": true }
// → complete · https://cdn.rendobar.com/o/job_4b8d/out.mp4 · 23.8 MB
You give it the ceiling, not a bitrate. The encoder searches candidate encodes and returns the smallest file that still clears the quality bar, so you are not guessing at CRF values to land under a mail server's limit.
Generate an image.
You: Make a 1920x1080 title card for a video about deep sea diving.
submit_job { "type": "image.generate",
"inputs": {},
"params": { "model": "standard",
"prompt": "Title card for a deep sea diving documentary. Shafts of light through deep blue water, small diver silhouette, empty space across the upper third for a title.",
"width": 1920, "height": 1080 } }
// → { "jobId": "job_2fa7", "status": "waiting" }
get_job { "jobId": "job_2fa7", "wait": true }
// → complete · https://cdn.rendobar.com/o/job_2fa7/out.png
inputs is empty because nothing is being transformed. Ask for a tier
(economy, standard, premium) and the platform picks the model, or pin an
exact model id to reach its own controls. Requested dimensions are snapped to
what the chosen model can actually render.
The rest of the surface
Six more tools, and the prompts that reach them.
You: What can Rendobar actually do?
list_job_types {}
// → { "jobTypes": [ { "type": "compose", "tag": "Compose",
// "summary": "Render a video from a declarative JSON timeline",
// "acceptsMedia": ["video", "image", "audio"] }, ... ],
// "guidance": "..." }
Read live from the job registry on every call, which is why nothing in this README enumerates job types. A new one appears here without a release.
You: How much credit is left?
get_account {}
// → { "balance": "$4.86", "balanceUsd": 4.86, "plan": "free", "isPro": false,
// "limits": { "concurrentJobs": 1, "maxFileSize": "500 MB", "jobTimeoutMin": 60 } }
Worth a call before submitting something expensive.
You: What did I run this morning?
list_jobs { "status": "complete", "limit": 5 }
// → { "jobs": [ { "id": "job_9f2a", "type": "ffmpeg", "status": "complete",
// "createdAt": "2026-08-04T09:12:00Z", "cost": "$0.01",
// "output": { "url": "https://cdn.rendobar.com/o/job_9f2a/out.mp4" } } ] }
The compact row is enough to find a result you lost. Call get_job when you
need the full output.
You: Stop that one, I picked the wrong file.
cancel_job { "jobId": "job_9f2a" }
// → { "id": "job_9f2a", "status": "cancelled" }
Works on waiting, dispatched and running jobs. A running job's upstream
execution is stopped too, so you are not billed for work you cancelled.
You: Where can this land once it's done?
list_storage {}
// → { "storage": [ { "id": "prod-media", "provider": "s3", "bucket": "acme-prod-media",
// "access": "deliver", "defaultDestination": true, "pending": false } ],
// "note": "..." }
The buckets connected on the Storage page, without the endpoint or region an
agent has no use for. Use the id in destinations, or as
storage://<id>/<path> in any input.
You: What's already in the archive bucket?
list_storage_files { "storageId": "raw-archive" }
// → { "folders": [ { "prefix": "2026/", "uri": "storage://raw-archive/2026/" } ],
// "files": [ { "key": "notes.txt", "size": 800, "lastModified": "2026-09-01T00:00:00.000Z",
// "uri": "storage://raw-archive/notes.txt" } ],
// "cursor": null }
Every entry carries its own storage:// uri, ready to hand straight to
submit_job. Pass a folder's prefix to go one level deeper.
Install
Rendobar has two MCP servers. Pick by whether the agent needs your filesystem.
Hosted, no API key, one command:
claude mcp add --transport http rendobar https://api.rendobar.com/mcp
Local, for filesystem access. Get a key at app.rendobar.com → Settings → API Keys, then:
claude mcp add rendobar -s user --env RENDOBAR_API_KEY=rb_... -- npx -y @rendobar/mcp
Already ran rb login with the Rendobar CLI? Drop --env. The server finds the credentials file.
Same block for all four. Claude Desktop: ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows). Cursor: ~/.cursor/mcp.json on every OS. Windsurf: ~/.codeium/windsurf/mcp_config.json on every OS. Cline: MCP panel → Configure.
On Linux, use Cursor, Windsurf, Cline, Zed, VS Code or Continue. Claude Desktop has no Linux build, so it is the one client on this list you cannot use there. The server itself runs fine on Linux.
{
"mcpServers": {
"rendobar": {
"command": "npx",
"args": ["-y", "@rendobar/mcp"],
"env": { "RENDOBAR_API_KEY": "rb_..." }
}
}
}
Restart the client afterwards.
Zed uses context_servers instead of mcpServers, in ~/.config/zed/settings.json:
{
"context_servers": {
"rendobar": {
"source": "custom",
"command": "npx",
"args": ["-y", "@rendobar/mcp"],
"env": { "RENDOBAR_API_KEY": "rb_..." }
}
}
}
VS Code 1.101+, in .vscode/mcp.json, prompts for the key instead of storing it:
{
"servers": {
"rendobar": {
"command": "npx",
"args": ["-y", "@rendobar/mcp"],
"env": { "RENDOBAR_API_KEY": "${input:rendobarKey}" }
}
},
"inputs": [{ "id": "rendobarKey", "type": "promptString", "password": true, "description": "Rendobar API Key" }]
}
Continue, in .continue/mcpServers/rendobar.yaml:
type: stdio
command: npx
args: ["-y", "@rendobar/mcp"]
env:
RENDOBAR_API_KEY: rb_...
Runs on macOS, Linux and Windows. Every release is tested on all three in CI. There are no native dependencies, so architecture does not matter: x64 and arm64 both work. Needs Node 20.10 or later, and the server checks at startup and exits with a clear message on older versions.
Tools
Job types
ffmpeg is the one to reach for first. It takes a command the way you would
write it locally, runs it on hosted infrastructure, and hands back a URL:
transcode, trim, mux, filter, concat, whatever the flags allow. Pass
params.compute as gpu to force NVENC encoding (Pro plan), or leave it on
auto and Rendobar routes CUDA commands to a GPU and everything else to CPU.
Beyond that there are purpose-built types for timeline composition, compression to a size budget, subtitle burn-in, animated captions, media inspection, image generation, image editing, and image upscaling.
Full reference: rendobar.com/docs/jobs. Or
call list_job_types, which reads the registry live and is always current. This
README deliberately does not enumerate them, so it cannot go stale.
Chaining
A submit_job input can point at a previous job's output, so a multi-step edit never round-trips through your disk. For ffmpeg inputs, pass { job: "job_..." }. For other types, read the output URL from get_job and pass that.
Your own storage
A file in a bucket connected on the Storage page is an input as storage://<id>/<path>. Add destinations: ["storage://<id>"] to submit_job and the output is written back to the bucket once the job completes, reported per bucket in get_job's deliveries. list_storage gives the ids and list_storage_files the paths. An API key made before September 13, 2026 cannot read storage, so create a new one. Credentials saved by rb login need a fresh rb login once rb asks for storage access.
Authentication
Three sources, first match wins:
--api-key=<key>flagRENDOBAR_API_KEYenvironment variable~/.config/rendobar/credentials.jsonon Unix,%APPDATA%\rendobar\credentials.jsonon Windows, written byrb login(Rendobar CLI 1.1+)
Installed as a .mcpb extension, the key goes in the extension's own settings field and none of the three above apply.
The server starts without a key so clients and directories can list its tools, and it makes no network call at startup. Nothing it advertises depends on the registry, so the job type list can never be baked into a build. list_job_types reads it live instead, and because GET /jobs/types is public it answers without a key at all. Every other tool returns a clear error until a key is set.
If you do not need Rendobar to read files off your machine, the hosted server at https://api.rendobar.com/mcp signs you in through the browser and there is no key to manage. The local server exists for disk access, and the key is the price of it.
Telemetry
The server reports anonymous usage through PostHog's MCP Analytics SDK: tool name, success, duration, and the agent's stated intent.
It never sends your parameters or responses. File URLs, job configs, and outputs are stripped before anything leaves the process. Events carry no account identity and build no person profile. It is off in CI automatically.
DO_NOT_TRACK=1 # or RENDOBAR_TELEMETRY=0
Troubleshooting
Cursor on macOS can't find npx. Launched from the Dock, Cursor gets the GUI PATH rather than your shell PATH. Use an absolute path: "command": "/Users/you/.nvm/versions/node/v20.x/bin/npx".
Windows can't find npx. Use "command": "npx.cmd" if your client doesn't resolve it.
Tools appear but calls fail with "No Rendobar API key configured". Expected with no key set. The server advertises tools so clients can list them, but calls need credentials. Set RENDOBAR_API_KEY, pass --api-key, or run rb login. Startup logs a no_api_key warning to stderr.
The server won't start. It writes JSON lines to stderr. Check your client's output panel for entries with level: "error".
Privacy Policy
Full policy: rendobar.com/privacy. What this server does specifically:
Collected. Your API key, read from the flag, the environment, or the credentials file. Job inputs you pass to a tool, and files you point upload_file at, are sent to the Rendobar API to run the job you asked for. Anonymous telemetry covers the tool name, whether it succeeded, how long it took, and the agent's stated intent.
Not collected. Tool parameters and responses. File URLs, job configs, and outputs are stripped before any telemetry leaves the process. Telemetry carries no account identity and builds no person profile. Nothing is read from your disk except the file paths you explicitly pass to upload_file.
Storage. Uploaded inputs and job outputs live in Rendobar's storage and are removed on the retention schedule for your plan. Telemetry goes to PostHog. The server keeps nothing on your machine beyond the credentials file the CLI writes.
Third parties. Rendobar (job execution and storage) and PostHog (anonymous telemetry). Opt out of telemetry entirely with DO_NOT_TRACK=1 or RENDOBAR_TELEMETRY=0.
Contact. [email protected], or open an issue on this repo.
Security
Reporting a vulnerability: see SECURITY.md.
Contributing
See CONTRIBUTING.md. For AI-assisted development, AGENTS.md and CLAUDE.md.
License
MIT