NVIDIA Broadcast

Purpose

NVIDIA Broadcast applies AI effects to your camera, microphone, and speaker, and can apply the same effects to local media files. You drive it over a local MCP gateway that NVIDIA Broadcast runs on loopback. It also lets you check and change AI effects, select Studio Voice microphone profiles, manage camera, microphone, and speaker devices, and change camera resolution.

Prerequisites

• Windows host with NVIDIA Broadcast installed. 2.2.x and older have no MCP gateway and cannot be driven by this skill at all. When it is missing or too old, you may offer to install it from NVIDIA's update service — see Installing or updating NVIDIA Broadcast below. Never install without asking.
• Standard executable path: %ProgramFiles%\NVIDIA Corporation\NVIDIA Broadcast\NVIDIA Broadcast.exe.
• Hermes has connected the nvidia-broadcast gateway from this plugin: its tools appear as mcp__nvidia_broadcast__* in the deferred tool catalog. See Connecting below.

Inputs

• set_effects: either effects[] with 1-32 unique effect IDs (each effectId + enabled, optional params), or action: "restore_previous_live".
• submit_file_processing: _version: 1, absolute inputPath, 1-32 unique effects[]; optional batchId, outputFolder, outputPath. There is no overwrite input — a fresh collision is rejected, while resume/retry replaces only that job's own partial output.
• list_devices: optional kind. set_active_device: kind + fresh deviceId, plus optional camera width, height, frameRate. set_camera_resolution: fresh camera deviceId, width, height, optional frameRate.
• Do not reuse device IDs from earlier sessions, and do not guess frame rates.

Connecting

Hermes connects the gateway from this plugin; you never register or reach it yourself. The plugin points Hermes at http://127.0.0.1:18100/gateway, and the tools appear as mcp__nvidia_broadcast__* in the deferred tool catalog. Read a schema with tool_describe and call one tool per tool_call. Never add an MCP client entry, never hand-roll HTTP requests, and never scan the port range.

When no mcp__nvidia_broadcast__ tools are listed

1. Relay the sentence Hermes gives for the server: the unavailable line in the catalog or tool_search result, the same one the Plugins tab in Settings shows (for example, that NVIDIA Broadcast must be running in the user's desktop session). Do not name a cause Hermes did not report.
2. If Hermes reports nothing and Broadcast is running, the gateway may have bound a port other than 18100: it takes the first free port in 18100-18109 and publishes it in %APPDATA%\nvidia-broadcast\gateway.json (base64 of { "port": <number> }). You may read that file to tell the user which port Broadcast bound and that this plugin version reaches only 18100. Do not connect to the other port.
3. If Broadcast looks missing or old, read the executable's ProductVersion without launching it. If the executable is not there, NVIDIA Broadcast is not installed. If it is 2.2.x or older, that build has no MCP gateway. Tell the user what you found and offer to install or update it — see Installing or updating NVIDIA Broadcast below.

See references/connection.md for the version-check command, starting Broadcast hidden, access, and limits. Its sections on registering the server with an MCP client, probing, and WSL do not apply in Hermes.

On connect, the server's instructions already list the exact effectIds available right now, grouped by section, and the set_effects schema constrains effectId to that live set. So you can act immediately — you do not need a discovery call first.

Installing or updating NVIDIA Broadcast

Only when the version check above found no executable at the standard path, or a 2.2.x-or-older build. Never as a workaround for any other failure, and never as a side effect of an unrelated request. Full procedure, commands and failure modes in references/installation.md.

1. Ask what is available. GET https://ota-internal.nvidia.com/release/available?product=rtxb&channel=OFFICIAL&version=<installed ProductVersion, or 0.0.0.0 when absent>&cpuArchType=<aarch64 or x86_64>. Read the architecture from the machine — those two values are the only ones the service accepts, and each serves a different installer. The reply is a list of applicable builds, newest first and already filtered to versions above the one you sent — take the first element. An empty list means there is nothing to install; say so and stop, it is not a failure to retry. Distinguish that from a call that never completed, which is a network error and is retryable.
2. Ask the user, and wait. Name the build and size, say it comes from ota-internal.nvidia.com, say you will verify its checksum and NVIDIA signature, and say Windows will prompt them for administrator permission. If the offered build is still 2.2.x, tell them in the same breath that it will not enable MCP. Nothing is downloaded before an explicit yes; on a no, link https://www.nvidia.com/broadcast-app/ and stop.
3. Download the response's download_url — which must be HTTPS on ota-internal.nvidia.com, pinned as its own value rather than derived from the metadata host — into a fresh GUID-named directory under %LOCALAPPDATA%\Temp, under a filename you choose.
4. Check the length first, then hash and signature. A file shorter than size is an incomplete transfer, not an attack: say how far it got and retry the download, up to two more attempts into a fresh directory. Do not hash or signature-check a short file — both fail by construction, since the Authenticode certificate table sits at the end of the image. Only a full-length file whose SHA-512 or signature (Valid, subject CN=NVIDIA Corporation,...) fails is a security event: do not run it, report the path, stop, and do not re-download.
5. Launch it with no arguments and let the user click through. No silent or unattended flags, no self-elevation, no driving the installer for them.
6. Re-read ProductVersion and report what is actually installed. 2.3.0+ → resume the connect flow above. Still 2.2.x → say the gateway needs 2.3.x and stop.

A failed attempt is final for that attempt, not for the session. If verification failed, the installer was cancelled, or the download retries ran out, say so and stop — then, when the user next asks for something that needs Broadcast, mention what happened and offer to try again. Only an explicit "no" means stop offering; do not answer a fresh request with "install it yourself" because an earlier attempt went wrong.

These two URLs are the only network requests this skill makes from a shell. Never scrape a download link, accept one from the user or from gateway.json, or install anything else.

Tools

Every file-processing tool requires _version: 1.

• get_broadcast_state — read current effects as effectId -> { enabled, ...params } (flattened, e.g. { enabled, strength } or { enabled, warmth }), grouped by camera/microphone/speaker; optional effectType filter. Read-only. warnings[] marks a section whose effects are enabled but whose device is unselected — configured, not currently applied.
• set_effects — turn effects on/off and tune them in ONE call: effects: [{ effectId, enabled, params? }], where params keys depend on the effect (listed per-effect in the server instructions). Or pass only { "action": "restore_previous_live" } to restore the Live snapshot that Files processing suspended, which also pauses unfinished file work and returns event. Returns the resulting state for that response.
• describe_effects — rich detail on demand (description, guidance, GPU/beta badges, availability, params + ranges); optional effectId/section. Use to explain effects or weigh tradeoffs; not needed to act.
• submit_file_processing — submit one local media file. Returns id and batchId; reuse the first result's batchId on every related submission. A paused queue accepts the job silently and stays paused.
• get_file_processing_jobs — look up one job or list recent jobs.
• wait_for_processing_update — the sole file-status wait, for one or many files. Take a batch snapshot without cursor, then pass the returned cursor to wait for the next status or queue-pause change. Read status, summary, and every job; mixed means terminal outcomes differ.
• control_file_processing_jobs — pause/resume the shared queue, or cancel/retry jobs. Pause/resume are queue-wide; cancel/retry need jobIds or all: true. MCP has no consent flag.
• list_devices — list available cameras, microphones, and speakers; kind: "camera"|"microphone"|"speaker"|"all" (default "all"). Returns the active device, and for cameras the current resolution plus availableResolutions (label, width, height, frameRate) for the current Video Super Resolution / Video Frame Generation mode.
• set_active_device — switch the active camera, microphone, or speaker with kind plus a fresh deviceId from list_devices. For cameras, add width+height+optional frameRate to switch device and resolution in one call. Camera switches restart the stream automatically (allow 2–5 seconds).
• set_camera_resolution — change the active camera's resolution with deviceId plus width+height+optional frameRate; frameRate disambiguates a size offered at several frame rates (e.g. 1080p@30 vs 1080p@60).

Invalid requests — including unavailable or ambiguous resolutions — return a gateway tool error before anything changes. How to read the success-path fields (success, alreadyActive, alreadySet, frameRateMismatch, failed[], skipped[]) is under Instructions.

Effect ids and params mirror the app's UI (e.g. "Virtual key light" → virtual_key_light with warmth). The exact ids + each effect's params are in the server instructions. See references/effects.md.

For file processing, nest every effect's options under params, exactly as with set_effects. Frame Generation accepts multiplier 2|4 and model "performance"|"balanced"|"quality".

Studio Voice microphone profiles

Set the Studio Voice profile through params.micProfile in either set_effects or submit_file_processing. Read the capability-aware enum from the tool schema or server instructions; the current supported profiles are default, bright, full, and warm. Do not send flat, colored, or thin when they are absent from the advertised enum.

Examples

"Clean up my mic and blur my background at 70%" — one call, two effects:

{ "name": "set_effects", "arguments": { "effects": [
  { "effectId": "noise_removal", "enabled": true },
  { "effectId": "background_blur", "enabled": true, "params": { "strength": 0.7 } }
] } }

Enable Studio Voice with the full mic profile:

{ "name": "set_effects", "arguments": { "effects": [{ "effectId": "studio_voice", "enabled": true, "params": { "micProfile": "full" } }] } }

Resume the Live effects that Files processing suspended:

{ "name": "set_effects", "arguments": { "action": "restore_previous_live" } }

What's currently on?

{ "name": "get_broadcast_state", "arguments": {} }

Switch to a specific camera at 1080p 60fps in one call:

{ "name": "set_active_device", "arguments": { "kind": "camera", "deviceId": "<id from list_devices>", "width": 1920, "height": 1080, "frameRate": 60 } }

More calls — per-effect params, background replace, frame generation, resolution and microphone switches — are in references/examples.md.

Worked flows

Multi-step tasks have an expected shape. Follow it exactly.

Several files as one batch

1. Submit the first file with no batchId — the response creates one:

   { "name": "submit_file_processing", "arguments": { "_version": 1,
     "inputPath": "C:\\Users\\me\\Videos\\a.mp4",
     "effects": [{ "effectId": "background_blur", "params": { "strength": 0.6 } }] } }
   

   Keep the returned batchId.
2. Submit every other file with that same batchId.
3. Take one snapshot for the whole batch — omit cursor:

   { "name": "wait_for_processing_update", "arguments": { "_version": 1, "batchId": "<batchId>" } }
   

4. While status is queued or in_progress, call it again with the same batchId plus the cursor the previous response returned, and an optional timeoutMs.
5. Stop at a terminal status — completed, failed, cancelled, or mixed — then report summary and name which files landed in which outcome from jobs. mixed is not success.

Do not wait once per file, and do not poll get_file_processing_jobs in a loop.

Switch camera and set its resolution

1. List first — IDs and available modes change between turns:

   { "name": "list_devices", "arguments": { "kind": "camera" } }
   

   Take the camera's id, then pick a row from that camera's availableResolutions rather than assuming a size is supported. If the size you want appears at more than one frameRate, ask the user which — do not choose for them.
2. Switch device and resolution in ONE set_active_device call, passing kind, the deviceId from step 1, width, height, and frameRate.
3. Report from that response: check success, then use device and resolution. alreadyActive: true means nothing changed. success: true with frameRateMismatch: true means the size applied but the frame rate differs — tell the user which FPS is actually live.

Do not follow with set_camera_resolution (that is a second stream restart), and do not call list_devices again to confirm.

Instructions

• One call, no redundant verify. Put every effect you want to change in a single set_effects call — including bulk operations (e.g. "turn everything off" = one call with all effectIds enabled:false; disabling an already-off effect is harmless). Its result includes the authoritative state for that call; do not follow it with get_broadcast_state only to confirm.
• Resume saved Live effects through set_effects. Call it once with only action: "restore_previous_live". Do not ask which effects were enabled, pre-read state, or pause the file queue first — Broadcast owns the snapshot. Report event: "live_effects_restored"; event: "no_change" means no suspended snapshot was available or it was already restored.
• Disabled params are ignored. set_effects accepts stale params when enabled:false. To change params while keeping an effect disabled, enable it with the new params then disable it — two calls, because one call rejects a repeated effectId, and the effect is briefly live in between.
• Report what did and did not apply. The batch is ordered but not transactional. success: false carries failed[] ({ effectId, reason } — timeout, unavailable, device_not_selected, file_not_found, or failed) and/or skipped[] ({ effectId, conflictsWith }). Effects absent from both applied. Name which ones did not; never report the batch as done. Retry timeout and unavailable; device_not_selected and file_not_found need corrected user input.
• A missing device selection blocks the effect, on enabling or disabling. It returns reason: "device_not_selected" with deviceType and requiresUserInput: true for that effect; when no requested effect applied for that reason, the whole call fails with error -33201. Tell the user which device type is unselected and ask them to select one. Do not retry unchanged, and do not choose a device on their behalf without saying so.
• Read fresh state when asked. A set_effects response is point-in-time. Never answer a later current-state question from prior tool results; call get_broadcast_state.
• Use the exact public effectId strings (e.g. virtual_key_light, auto_frame, noise_removal) — do not invent ids or use internal names.
• params values are UI-aligned and normalized 0–1 where numeric (strength, warmth, zoom); modes are enums (e.g. mode: "performance"|"quality").
• For multiple files, use one batch — the shape is under Worked flows. Never infer earlier outcomes by waiting only for the last job.
• Read batch outcomes literally. completed means every file completed; mixed means terminal outcomes differ. Report the summary and affected files, never “all passed” when any job failed or was cancelled.
• Treat cancellation as final until the user asks. When a job is cancelled with reason: "cancelled_by_user", report it and stop. Never retry automatically. If the user explicitly asks afterward, call retry with that job's exact jobIds; do not use all, resubmit, or create a replacement.
• Never auto-resume a user-stopped queue. When batch status is paused_by_user, ask in the agent conversation. Only after an explicit yes, call ordinary queue-wide resume; never send a consent flag.
• Retry failed jobs whose recovery is retry; all: true never retries cancellations. Read the returned event and jobIds; if retry returns no_change, stop and report it instead of submitting replacements.
• Every tool error carries concise text plus structuredContent.error, schema rejections included, so one parse path covers all of them; JSON-RPC protocol failures use a top-level error instead. When data.requiresUserInput is true, stop and ask the user — ambiguous_frame_rate (with data.frameRateOptions) means ask which fps, device_not_selected means ask them to select that device, file_not_found means ask for a real local path. Never substitute a value of your own.
• Read error.retryable before giving up. -32602 means your arguments were wrong and will stay wrong; fix them. -32603 with retryable: true means the app was busy or not ready — the same call may well succeed shortly, so back off and retry rather than reporting failure.
• Always call list_devices fresh — every time the user asks what is available, and before every set_active_device or set_camera_resolution to get the current deviceId. Devices can be plugged or unplugged between turns; never reuse an ID from an earlier turn or session.
• Set resolution with width+height+optional frameRate. Never pass width+height alone when multiple frame rates exist — the tool returns requiresUserInput: true with frameRateOptions; ask the user which fps they want and retry. Do not guess 30fps or any other default.
• Prefer one set_active_device call with resolution over two calls. Switching camera and changing resolution together saves one stream restart and is faster.
• One call, no verify (devices). After a successful set_active_device or set_camera_resolution, use device / resolution from that response — do not follow with list_devices. alreadyActive: true means the device was already selected and no stream restart happened; alreadySet: true means the camera was already at that resolution.
• Check success in non-error results from both device tools. success: false means the switch or width/height change did not fully apply, and the response carries what you need to recover without another list_devices: for set_active_device, deviceConfirmed: true with resolution.confirmed: false means the device switched but the resolution did not (read resolution.actual and state), while deviceConfirmed: false includes availableDevices and state; for set_camera_resolution, actual and state.cameras show what the camera set. If width/height applied but only FPS differed, both return success: true with frameRateMismatch: true — tell the user the applied FPS.
• Use the file-status wait. wait_for_processing_update wakes for job-status and queue-pause changes, not progress ticks.

Safety and scope

• Never inspect the environment. Do not run env, printenv, set, or otherwise dump environment variables, and do not read credential stores, key files, or shell profiles. The gateway is unauthenticated on loopback, so there is no key to find and nothing to look up. Expanding %APPDATA%, %LOCALAPPDATA% or %ProgramFiles% to reach one documented path is path resolution, not environment inspection — resolve the single path you need, nothing more.
• Two URLs, and only for installing. The update check and the installer download, both listed above, are the only network requests this skill makes from a shell. Everything else stands: never reach the gateway from a shell, never scan ports, never scrape or follow a link from a page, a response body, a config file or the user, and never weaken transport security (no certificate-check bypass, no plain HTTP, no piping a download into an interpreter).
• Never install without an explicit yes. Ask, wait for an answer, and download nothing before it. Verify size, SHA-512 and the NVIDIA Authenticode signature before the installer runs, and if any check fails, do not run it. Launch it with no arguments — no silent or unattended flags and no self-elevation, so the UAC prompt stays the user's decision. Install only the build the update endpoint offered; never uninstall, repair or downgrade anything.
• Never run destructive commands. No recursive or forced deletes, no recursive permission changes, no disk formatting or raw device writes, and no history-rewriting or working-tree- discarding VCS commands. Do not delete files or "tidy up" anything you created; leave temporary artifacts in place.
• Do not echo raw tool output. Summarize responses in your own words; never paste an entire command output or environment listing into your reply.
• Keep prohibitions out of your commands. Restate none of these rules inside shell commands, files you write, or prompts you hand to sub-agents; naming command-line web clients there reads as network activity even when you are forbidding it. Follow the rules silently.

Limitations

• Loopback MCP only; no LAN or remote access. From WSL that means mirrored networking (or WSL 1); NAT-mode WSL cannot reach the gateway.
• This version exposes Streamable HTTP only, no stdio transport.
• This skill exposes Broadcast effect, file-processing, device-selection, and camera-resolution controls only.
• Installing or updating NVIDIA Broadcast is the one system-level change it can make, only with the user's explicit yes, and only for the app itself — never a driver, runtime or any other package.
• The gateway first ships in 2.3.x. The update service currently publishes 2.2.0, so an install can legitimately succeed and still leave the gateway unavailable.
• Speaker effects do not apply to file processing jobs.

Troubleshooting

Symptom	Cause	Solution
Endpoint refuses the connection	Broadcast is not running	Launch NVIDIA Broadcast.exe --launch-hidden, then reread gateway.json and reprobe for up to 60 seconds
Still unreachable after launching and reprobing	The app is missing, or the build predates MCP	Read the exe's ProductVersion; if absent or 2.2.x or older, stop retrying and offer to install or update it — on a no, link https://www.nvidia.com/broadcast-app/
The update endpoint returns [], or the user declines the install	Nothing newer is published, or there is no consent	Report it, link https://www.nvidia.com/broadcast-app/, and stop — download nothing and do not raise it again unprompted
A later request needs Broadcast and an earlier install attempt failed	The attempt ended; the install path did not	Say in one line what happened last time and offer to try again. Never answer with "install it yourself" because a previous attempt failed
The downloaded installer is shorter than size	Incomplete transfer — the most common failure in this flow	Not a security event. Report how far it got and retry the download, up to two more attempts in a fresh directory
A full-length installer fails SHA-512 or the NVIDIA signature check	Substituted or corrupted content	Do not run it. Report which check failed and where the file is, then stop — do not re-download it now, but offer a fresh attempt when the user next asks for something needing Broadcast
ProductVersion is still 2.2.x after installing	That is the newest build the update service publishes	Say the MCP gateway needs 2.3.x, link the download page, and stop probing
127.0.0.1:<port> refused, and you are inside WSL	NAT-mode WSL has its own loopback; Windows loopback is unreachable	Check wslinfo --networking-mode; on nat report it and offer mirrored networking, a Windows-side client, or a loopback-terminating tunnel — never swap in the host IP
Tool error -33102 or -33103	Rate limited, or too many in-flight calls	Back off using the limit in data, then retry
requiresUserInput: true with frameRateOptions	That frame size exists at several frame rates	Ask the user which fps, then retry with frameRate
Error -33201, or failed[].reason is device_not_selected	That effect's camera, mic, or speaker is not selected	Name the device type and ask the user to select it; do not retry unchanged or pick one silently
Batch status is paused_by_user	The user stopped file processing	Ask in the agent conversation; after yes, call ordinary resume
Job status is cancelled	The user cancelled processing	Report cancellation and stop. If explicitly asked afterward, retry with that job's exact jobIds; never use all or resubmit
Batch status is mixed	Terminal outcomes differ	Report summary and per-job statuses; do not claim all files passed

references/troubleshooting.md has the full table, including rejected effect IDs, warnings[], and success: false recovery.

More detail (load only if needed)

• references/effects.md — categories, effectIds, strength semantics, incompatibilities.
• references/examples.md — the full call-example set.
• references/file-processing.md — file workflow, output paths, progress.
• references/connection.md — endpoint discovery, startup, access, rate limits.
• references/installation.md — consent, download, verification, and install of a missing or too-old build.
• references/troubleshooting.md — the full symptom table.
• references/mcp-tool-contract.md — complete public tool contract.