Setup guide

Free Alpha

Follow these steps in order to avoid setup conflicts. Steps 1 to 5 install the software, steps 6 to 8 connect your own AI account, and steps 9 and 10 run and end a session.

Before you begin

You need all of these
  • A Windows GM host — Windows 10 / 11 (64-bit). The companion runs on the machine hosting the campaign.
  • Fantasy Grounds Unity running the 5E ruleset.
  • The Nerve extension, installed through the Forge — free. The extension on its own provides no AI service.
  • The separate Nerve Windows companion.
  • Node.js 22 or newer.
  • A compatible external AI application and account. AI access, allowance and costs are not included with Nerve — your provider bills you, not us.

Selected campaign context and source references are sent to the AI provider you choose, and that can include GM-only material. Read privacy and data flow and get your group's agreement before you put their campaign through a provider.

Install and connect — ten steps

  1. Back up your campaign, and start with a test copy

    Do not learn Nerve on the campaign you care about. Make a backup, then make a throwaway copy of a campaign and do your first sessions there. Nerve can change campaign records through supported actions, and this is alpha software.

  2. Install the Nerve extension through the Forge, then run the updater

    Add the Nerve item to your Forge library, then launch Fantasy Grounds and let the updater run so the extension is actually downloaded to your machine. Installing the Forge item without running the updater leaves you with nothing installed.

    Current packaging targets Forge Data installation, not encrypted Vault delivery.

    Get Nerve on Forge ↗
    Not yet proven end to end

    The listing is public and free, and the extension is assigned to Live with Data installation. We have not yet tested acquiring it while signed in and installing it through the Fantasy Grounds updater from a clean profile. If this step misbehaves, that is worth reporting in the forum thread ↗.

  3. Install Node.js, then download and fully extract the companion

    Install Node.js 22 or newer if you do not have it. Then download the companion ZIP that matches your extension version from Downloads, verify its SHA-256 checksum, and extract the ZIP completely before running anything.

    Match the version, do not assume the newest

    The extension and the companion must be the same version. When Fantasy Grounds loaded in step 2 it printed a line like Nerve Adapter v0.68.7 loaded. — download the companion carrying that version, even if a newer one is published.

    Both halves are on the same version at the moment, so the newest companion on the downloads page is the right one.

    Both 0.68.7 components notice a mismatch themselves and tell you which half to update, but it is quicker to get the pair right the first time.

    Extract, do not browse

    Running the installer from inside Windows' zip preview — without extracting first — is a frequent cause of a half-installed companion. Extract the archive to a real folder, then open that folder.

  4. Run Install-Nerve.cmd and answer its prompts

    From the extracted folder, run Install-Nerve.cmd. It will ask which campaign to attach to and what role to configure. Answer with the test campaign from step 1.

    Leave the installer open

    The installer may pause and ask you to load the extension and campaign in Fantasy Grounds before it can finish. That is expected. Do not close it. When it prompts, carry out step 5 in Fantasy Grounds, then come back to this window and let the installer complete. Steps 4 and 5 overlap by design — you are not waiting for one to finish before starting the other.

  5. Enable Nerve Adapter in Fantasy Grounds and confirm the version

    Launch Fantasy Grounds, enable the Nerve Adapter extension for your campaign and load the campaign. If the installer from step 4 is waiting on you, this is the moment it is waiting for — do this, then return to it.

    Fantasy Grounds announces the adapter on load. Expect: Nerve Adapter v0.68.7 loaded. The extension and the runtime both report a bare version number (0.68.7); alpha is the release channel and the download filename suffix, not part of what Fantasy Grounds prints. Confirm it matches the companion you installed — mismatched halves cause connection and compatibility errors.

  6. Open Nerve Control → AI Setup and select your provider

    The Nerve control appears in the Fantasy Grounds sidebar with this icon. Open Nerve Control, go to AI Setup, and select the provider you intend to use. If the provider needs local components, use Install / Repair first, then Sign In.

  7. Complete your provider's own sign-in

    Authentication is owned by your provider, not by Nerve. A browser window may not appear at all if you are already signed in — that is normal, not a failure.

    Signing in to the provider's website is not enough

    Being logged in to an ordinary browser chat session does not establish the listener connection Nerve needs. You have to complete sign-in through the AI Setup flow.

  8. Run Test + Use, and check which provider succeeded

    Use Test + Use and confirm both that the test succeeded and that the provider it reports is the one you meant to select. Do not start play on an untested connection.

    Tests and gameplay both consume your provider allowance. Provider charges and account limits are controlled by your provider: Nerve does not include an AI allowance or guarantee a spending cap for signed-in application usage.

  9. Start Nerve and begin a session

    Start Nerve to open a tracked session. New tracked sessions default to Flow Mode. In Flow Mode, supported narration, proxy actions and pacing can run automatically, including supported exact-source encounters; guarded actions still require your approval. If you would rather approve more of it yourself, switch to manual approval before you play rather than during a scene.

    You can stop the connector at any time. Stop Nerve cancels what is in flight — it is not an undo. Anything already applied to campaign records stays applied.

  10. End Session, confirm the connector stopped, and check the records

    Use End Session and confirm the connector has actually stopped. Then inspect the native Fantasy Grounds records for anything an action claimed to change — inventory, currency, quests, combat. Narration is not proof that a record changed.

How updates work

Nerve updates along two separate paths, and they must stay in step:

Two pieces, two update paths
PieceUpdated byHow
Nerve extension Fantasy Grounds Update the Forge item, then run the Fantasy Grounds updater.
Nerve companion The companion installer Download the matching ZIP, extract completely, run Install-Nerve.cmd.

Always check the release notes for the version pairing before updating one half on its own.

Migrating from a developer preview

If you have been running a developer preview build, do not install the packaged extension on top of it. Fantasy Grounds will find two copies and behave unpredictably.

An old unpacked extension can mask the Forge one

This is the failure worth knowing about: if a previously unpacked development copy is still sitting in your extensions folder, Fantasy Grounds can load that instead of the extension Forge installed. Everything looks installed, the version you see is the old one, and nothing lines up with the companion. Move the old folder out first — the steps below — rather than assuming the Forge install did not work.

  1. Close Fantasy Grounds completely

    Fully exit — not just the campaign.

  2. Move the old extensions/Nerve folder out of extensions

    Move it somewhere you can get it back from — your desktop is fine. Move it out of the extensions folder entirely; renaming it in place is not enough.

    Never delete campaign data

    This step touches the extension folder only. Your campaigns, characters and modules are somewhere else and must be left alone. If an instruction anywhere tells you to delete campaign data to fix Nerve, it is wrong — tell us.

  3. Install the packaged extension from the Forge

    Then run the Fantasy Grounds updater, as in step 2 above.

  4. Re-run the Forge companion installer

    Run Install-Nerve.cmd from the new companion package so the runtime is repointed at the packaged extension.

If Fantasy Grounds warns you about duplicate Nerve copies, you are seeing the problem these steps fix — come back here rather than deleting anything.

Troubleshooting

Each row is a concrete next step, not a diagnosis. If none of them fit, send us a bug report with your exact error code.

Common problems and what to do next
What you see Likely cause Next step
Nerve controls appear but nothing responds The companion is not installed or not running. The extension cannot reach a provider on its own. Install the companion (steps 3 and 4) and confirm it is running on the GM host.
Sign-in never completes, or no browser opens You are already signed in, or sign-in was done in an ordinary browser tab. No browser window is expected if you are already signed in. Ordinary browser chat sign-in does not establish the listener — redo sign-in through AI Setup.
Responses come from the wrong provider A different provider is selected than the one you signed in to. Run Test + Use and read which provider it reports before playing. Reselect in AI Setup if it is not the one you want.
Version mismatch, or odd behaviour after an update Extension and companion are on different versions. Reload the campaign and confirm the reported version. Check the release notes pairing and update whichever half is behind.
Fantasy Grounds warns about duplicate extensions A developer-preview folder is still in extensions. Follow migration. Move the old folder out to a recoverable backup — do not delete campaign data. An unpacked development copy can be loaded instead of the Forge-installed extension, which looks like the Forge install failing when it did not.
Response is slow, or times out Provider latency, or a request that has already failed. Built-in listeners normally time out after three minutes. Wait it out rather than clicking Call Nerve again — avoid repeated Call Nerve clicks while responding; they do not speed up the current request.
APP_LISTENER_PROTOCOL_FAILED Several causes. On Grok in this candidate, a detailed "Rate limited" message can surface under this code. Read the detail text under the code before concluding anything. A timeout on its own is not proof of subscription throttling. Include the full message in a bug report.
You approved an action but nothing visibly changed The record may have changed without an obvious interface cue — quest completion in particular. Open the native record and check it directly. Quest completion can be updated through supported actions but is not clearly visible in the standard quest interface. If the record really is unchanged, that is a bug worth reporting.
Stop Nerve did not undo what happened Working as designed. Stop Nerve cancels in-flight work; it is not an undo. Check the native record first, then correct it manually — correcting without checking may duplicate an update that already applied.

Where to ask

The public Fantasy Grounds thread is the fastest route for anything another tester might recognise, and it is where we post known issues. Redact personal information, credentials and private campaign material before posting, and keep support bundles out of public posts. For anything you would rather not put in the open, send a private report instead.

Discussion and bug reports ↗ Send a private report

Support bundles

The companion ships with Collect-Nerve-Support.cmd, which gathers diagnostic information into a single bundle. Do not attach a bundle to the public feedback form — bundles can contain campaign content and account details. Review the contents yourself, and share one privately only if we ask you for it.

Fantasy Grounds and the Forge are operated by SmiteWorks, which has not endorsed or certified this product.