Channel Unit Status Codes¶

Nerve Migration Guide¶

This document covers the changes needed when migrating integrations or scripts from WebSQ to Nerve. The core protocol is the same (JSON-RPC 2.0 over HTTP POST /api, WebSocket /counts and /updates), but there are renamed methods, removed methods, parameter changes, and configuration structure changes.

Table of Contents¶

1. Overview

2. Startup & CLI Flags

3. HTTP Endpoints

4. JSON-RPC Method Changes

   • Renamed Methods

   • Removed Methods

   • New Methods

   • Parameter Changes

5. Settings / Configuration Structure

   • Top-Level Keys

   • Backend Fields

   • Channel Structure

6. Data Download & Recording

7. WebSocket & SSE Events

1. Overview¶

2. Startup & CLI Flags¶

WebSQ¶

python -m websq               # run with simulation and frontend serving
python -m websq -noserv       # disable frontend serving
python -m websq -nosim        # disable simulation
python -m websq --port 9000   # custom port

Nerve¶

./nerve                              # production mode (serves built frontend)
./nerve -sim                         # enable simulation (was default in WebSQ)
./nerve -dev                         # disable built frontend serving (use npm dev server)
./nerve -port 9000                   # custom port
./nerve -cfgdir /etc/nerve           # custom config directory
./nerve -logdir /var/log/nerve       # custom log directory
./nerve -tmpdir /data/tmp            # custom temp directory

Key change: Simulation is now opt-in (-sim) instead of opt-out.

3. HTTP Endpoints¶

File Upload¶

WebSQ had a single firmware upload endpoint. Nerve uses a generic /upload/:fileType route:

File Download¶

All data that was previously returned as RPC response payloads is now served as file downloads:

4. JSON-RPC Method Changes¶

Renamed Methods¶

Removed Methods¶

These WebSQ methods no longer exist in Nerve. Use the indicated replacement.

New Methods¶

These methods are available in Nerve but did not exist in WebSQ.

Parameter Changes¶

setRecord (replaces startRecording / stopRecording)¶

Recording is now a single toggle method instead of separate start/stop methods. The channels parameter from startRecording is no longer accepted — all active channels are recorded automatically.

WebSQ start recording:

{"jsonrpc":"2.0","method":"startRecording","params":{"channels":[1,2,3]},"id":1}

Nerve start recording:

{"jsonrpc":"2.0","method":"setRecord","params":{"value":true},"id":1}

WebSQ stop recording:

{"jsonrpc":"2.0","method":"stopRecording","params":{},"id":1}

Nerve stop recording:

{"jsonrpc":"2.0","method":"setRecord","params":{"value":false},"id":1}

The response contains {"value": bool} reflecting the actual recording state after the call.

reboot¶

WebSQ used an optional delay field in milliseconds. Nerve accepts an optional delay parameter as well — the interface is compatible.

setChannelLog¶

The parameter names are the same (debug, rank), but rank is now a uint32 channel rank rather than a 1-based integer. When debug is false, the rank parameter is optional and all channel logging is disabled.

5. Settings / Configuration Structure¶

Top-Level Keys¶

The configuration JSON structure has changed at the top level:

Backend Fields¶

Channel Structure¶

This is the most significant structural change. WebSQ organized channels in a nested map by MCU ID then CU ID. Nerve uses a flat map keyed by a sequential rank number.

WebSQ devices structure:

{
  "devices": {
    "1": {
      "configuration": { "mcuId": 1, "mcuStatus": 0 },
      "channels": {
        "1": { "mcuId": 1, "cuId": 1, "biasI": 1.5e-5, ... },
        "2": { "mcuId": 1, "cuId": 2, "biasI": 1.2e-5, ... }
      }
    }
  }
}

Nerve channels structure:

{
  "channels": {
    "1": { "mcuId": 1, "cuId": 1, "biasI": 1.5e-5, ... },
    "2": { "mcuId": 1, "cuId": 2, "biasI": 1.2e-5, ... }
  }
}

The rank key is a flat uint32 that uniquely identifies each channel across all MCUs.

biasI units are unchanged: Both WebSQ and Nerve store biasI in Amperes (e.g., 1.5e-5) in the settings file and in the API. The frontend converts to/from μA for display only.

New voltage-mode bias fields in Nerve: The Nerve channel unit gains biasV, biasVStart, biasVStop, and biasVStep for voltage-controlled bias sweeps. These have no WebSQ equivalent.

6. Data Download & Recording¶

In WebSQ, IV and recording data was returned directly in JSON-RPC responses (getIvData, getRecordData, getIvFile). In Nerve, all data export is done via HTTP downloads.

Downloading recorded data¶

# WebSQ (RPC call returning data in JSON)
POST /api  {"method": "getRecordData", ...}

# Nerve (HTTP file download)
GET /download/recordings

Downloading IV sweep data¶

# WebSQ
POST /api  {"method": "getIvData", ...}
POST /api  {"method": "getIvFile", ...}

# Nerve
GET /download/ivsweep

Downloading configuration¶

# WebSQ (no equivalent — config was only readable via getSettings)

# Nerve
GET /download/config

7. WebSocket & SSE Events¶

The /updates WebSocket still carries JSON-RPC 2.0 notification objects ({"jsonrpc":"2.0","method":"...","params":{...}}). Most event names are unchanged.

New SSE endpoint¶

GET /terminal_output is a new Server-Sent Events stream that emits firmware upgrade output line by line. There is no WebSQ equivalent; upgrade progress was not streamed.

Quick Reference: Method Compatibility¶