{"record":{"id":"2c3dc1701ee7c69b","repo":"JuliusBrussee/caveman","slug":"key-must-be-a-string","errorCode":null,"errorMessage":"${key} must be a string","messagePattern":"(.+?) must be a string","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"warning","filePath":"packages/cli/src/agent-mcp.ts","lineNumber":511,"sourceCode":"    if (typeof monitor.id !== \"string\" || monitor.id.trim() === \"\") throw new Error(\"filter monitor.id is required\");\n    if (typeof monitor.verdict !== \"string\" || ![\"pass\", \"fail\", \"error\"].includes(monitor.verdict)) {\n      throw new Error(\"filter monitor.verdict must be pass, fail, or error\");\n    }\n  }\n}\n\nfunction optionalEnum(args: JSONObject, key: string, values: string[]): void {\n  const value = args[key];\n  if (value !== undefined && (typeof value !== \"string\" || !values.includes(value))) {\n    throw new Error(`${key} must be one of ${values.join(\", \")}`);\n  }\n}\n\nfunction validateTraceSearch(args: JSONObject): void {\n  validateTraceFilters(args);\n  for (const key of [\"from\", \"to\"]) {\n    const value = args[key];\n    if (value !== undefined && typeof value !== \"string\") throw new Error(`${key} must be a string`);\n  }\n  optionalEnum(args, \"date_field\", [\"occurred\", \"updated\"]);\n  optionalEnum(args, \"group_by\", [\"session\", \"workflow\", \"model\", \"member\"]);\n  const pageSize = args.page_size;\n  if (pageSize !== undefined && (!Number.isSafeInteger(pageSize) || (pageSize as number) < 1 || (pageSize as number) > 500)) {\n    throw new Error(\"page_size must be an integer from 1 to 500\");\n  }\n  const sort = args.sort;\n  if (sort !== undefined) {\n    if (!sort || typeof sort !== \"object\" || Array.isArray(sort)) throw new Error(\"sort must be an object\");\n    const unknown = Object.keys(sort).filter((key) => key !== \"by\" && key !== \"dir\");\n    if (unknown.length > 0) throw new Error(`sort has unknown key(s): ${unknown.sort().join(\", \")}`);\n    optionalEnum(sort, \"by\", [\"timestamp\", \"total_cost_usd\", \"latency_ms\", \"total_tokens\"]);\n    optionalEnum(sort, \"dir\", [\"asc\", \"desc\"]);\n  }\n  const cursor = args.cursor;\n  if (cursor !== undefined) {\n    if (!cursor || typeof cursor !== \"object\" || Array.isArray(cursor)) throw new Error(\"cursor must be an object\");","sourceCodeStart":493,"sourceCodeEnd":529,"githubUrl":"https://github.com/JuliusBrussee/caveman/blob/27d5a3981a347890211bb1bf2439e5c821a63bc9/packages/cli/src/agent-mcp.ts#L493-L529","documentation":"In validateTraceSearch(), the optional date-window arguments `from` and `to` must be strings when present. Numbers (Unix timestamps as ints), Date objects stringified by a client into something else, null, or arrays throw with the key named. There is no format enforcement at this layer beyond the string type — the backend interprets the values.","triggerScenarios":"from: 1700000000 (epoch seconds as number); from: null used to mean \"no bound\"; from: [\"2024-01-01\"] wrapped in an array by a generic serializer.","commonSituations":"Programmatic callers converting dates to epoch ints; optional-field handling that sends null instead of omitting; a model emitting a number where an ISO string was expected.","solutions":["Send ISO-8601 strings: from: \"2026-08-01T00:00:00Z\".","Omit from/to entirely for an unbounded window — never null.","Convert epochs explicitly: new Date(ms).toISOString()."],"exampleFix":"// before\n{ from: 1754006400, to: null }\n\n// after\n{ from: new Date(1754006400000).toISOString() }","handlingStrategy":"type-guard","validationCode":"for (const k of [\"from\", \"to\"]) {\n  const v = args[k];\n  if (v !== undefined && typeof v !== \"string\") throw new Error(`${k} must be a string`);\n}","typeGuard":"function isDateString(v: unknown): v is string {\n  return typeof v === \"string\" && !Number.isNaN(Date.parse(v));\n}","tryCatchPattern":null,"preventionTips":["Convert Date objects and epoch numbers with toISOString() before calling.","Omit from/to for open windows; never send null."],"tags":["mcp","validation","dates","traces"],"backgroundTag":null,"analyzedSha":"27d5a3981a347890211bb1bf2439e5c821a63bc9","analyzedAt":"2026-08-15T09:26:11.751Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}