Troubleshooting

Each entry gives the message as wickworks sends it, what causes it, and the fix. Over REST the message is in detail; over MCP the same text comes back in an isError result, prefixed with Error executing tool compute:.

400: insufficient bars 

insufficient bars: have 30, but: slowSma (type=sma) needs 200, longRsi (type=rsi) needs 51

One or more requested indicators need more history than you sent. The 400 body also has a deficits array with outputKey, type, required and available for each one; see insufficient bars.

Fix: send at least the largest required value, or shorten the indicator’s lengths. Every SMC output and summary needs MIN_BARS (default 50).

400: unknown indicator type 

unknown indicator type 'foo' for output 'foo'

The output key, or its type, is not a known indicator. Types are case sensitive: orderBlocks, not orderblocks. A key you invent as an output name needs a type:

{
  "fastRsi": {
    "type": "rsi",
    "length": 7
  }
}

Fix: use a name from the indicator reference or SMC page, or call the MCP list_indicators tool.

400: unknown parameters 

indicator 'rsi': unknown parameters: len

The spec has a parameter the indicator does not take. wickworks rejects it instead of ignoring it, so a typo never runs with the default by accident.

Fix: use the parameter names from the indicator’s table. Remember type is not a parameter of the indicator; everything else in the object is.

400: invalid parameter values 

indicator 'macd': fast must be less than slow

Other messages of this kind:

  • <name> must be a positive integer (lengths and windows)
  • <name> must be a positive finite number (multipliers, std, af, rangePercent)
  • <name> must be a non-empty string
  • sessionOffset is not a valid duration
  • fast, medium, and slow must increase (uo)
  • tenkan, kijun, and senkou must increase (ichimoku)
  • step must not exceed max (psar)
  • rangePercent must not exceed 1 (liquidity)
  • timeFrame must be one of: ... (previousHighLow)
  • session must be one of: ... (sessions)
  • startTime must use UTC HH:MM, endTime must use UTC HH:MM
  • Custom session requires startTime and endTime
  • startTime and endTime are only valid for Custom session

Each message starts with indicator '<output key>':, so you know which entry to fix.

400: empty bars or indicators 

bars must not be empty

indicators must not be empty

Fix: send at least one bar and at least one indicator.

413: too many bars 

too many bars: 6000 > MAX_BARS=5000

Fix: send fewer bars, or raise MAX_BARS on the server.

422: bar validation

422 responses list each problem with its location. The common ones:

msg Cause
Value error, bar times must be strictly increasing and unique Two bars share a time, or the bars are not oldest first
Value error, high must be greater than or equal to low A bar has high < low
Value error, open must be between low and high open lies outside the bar’s range
Value error, close must be between low and high close lies outside the bar’s range
Input should be greater than 0 A price is zero or negative
Input should be greater than or equal to 0 volume is negative
Field required A bar is missing a field, often volume
Extra inputs are not permitted An unknown field, such as tickVolume or realVolume from before 0.7.0, or a top-level field such as recentBars
Value error, indicator '<key>' must be true or an object A spec is false, a string or a number

The loc array points at the field, for example ["body", "bars", 5, "tickVolume"].

Fix the data, or map your vendor’s volume field to volume before sending.

Standard JSON cannot carry NaN or Infinity. Some encoders write them anyway as bare NaN and Infinity tokens. wickworks rejects such a value, but the 422 response then fails to serialize, and the client gets a plain-text Internal Server Error with status 500 instead. Drop or fill missing values before sending.

500: indicator computation failed 

indicator computation failed

An indicator raised an error that validation did not catch. The server log has the traceback, under compute failed for <symbol> <timeframe>.

One known cause: a vwap anchor other than "D", "W" or "M" passes validation and then fails inside pandas-ta. Use one of those three. For anything else, open an issue with the request body.

The first request is slow

The first request that needs SMC objects or summaries in a new container takes several seconds while numba compiles. Later requests are fast. See scaling.

/health reports 0.0.0+unknown

You are running the service from source with make run, where the package is not installed and has no version metadata. The Docker image reports the real version.

An MCP client gets a redirect or 404

Use http://<host>:8000/mcp or /mcp/. Both work. A path such as /mcp/mcp does not. Clients that need a stdio server should use the plugin instead of pointing at the URL directly.