Errors

Last updated: 16 Jun 2026

Canvas uses conventional HTTP response codes to indicate success or failure of an API request. In general: Codes in the 2xx range indicate success. Codes in the 4xx range indicate an error that failed given the information provided (e.g., a required parameter was omitted, a request wasn’t found, etc.). Codes in the 5xx range indicate an error with Canvas’ server.

All 4xx errors that could be handled programmatically (e.g., resource not found) include an OperationOutcome that explains the error reported

Error Code	Description
200 - OK	Everything worked as expected.
400 - Bad Request	The request was malformed or rejected by validation.
401 - Unauthorized	No valid Bearer token provided.
403 - Forbidden	Token bearer is forbidden from performing the operation.
404 - Not Found	The requested resource doesn’t exist.
412 - Precondition Failed	A conditional request failed because the resource has been modified since the precondition was specified.
422 - Unprocessable Entity	The request was syntactically correct but failed due to request semantics, database state, or a business rule.
5XX - Server Error	Something went wrong on Canvas’s end.

400

{
  "resourceType": "OperationOutcome",
  "issue": [
    {
      "severity": "error",
      "code": "invalid",
      "details": {
        "text": "The request was malformed or failed validation."
      }
    }
  ]
}

401

{
  "resourceType": "OperationOutcome",
  "issue": [
    {
      "severity": "error",
      "code": "unknown",
      "details": {
        "text": "Authentication failed"
      }
    }
  ]
}

403

{
  "resourceType": "OperationOutcome",
  "issue": [
    {
      "severity": "error",
      "code": "forbidden",
      "details": {
        "text": "Authorization failed"
      }
    }
  ]
}

404

{
  "resourceType": "OperationOutcome",
  "issue": [
    {
      "severity": "error",
      "code": "not-found",
      "details": {
        "text": "Unknown Patient resource 'a47c7b0ebbb442cdbc4adf259d148ea1'"
      }
    }
  ]
}

412

{
  "resourceType": "OperationOutcome",
  "issue": [
    {
      "severity": "error",
      "code": "conflict",
      "details": {
        "text": "The resource has been modified since the precondition was specified."
      }
    }
  ]
}

422

{
  "resourceType": "OperationOutcome",
  "issue": [
    {
      "severity": "error",
      "code": "business-rule",
      "details": {
        "text": "This appointment time is no longer available."
      }
    }
  ]
}

5XX

{
  "resourceType": "OperationOutcome",
  "issue": [
    {
      "severity": "error",
      "code": "exception",
      "details": {
        "text": "Internal server error"
      }
    }
  ]
}