siyuan-note/siyuan · error

Field [id] should be of type [String]

Error message

Field [id] should be of type [String]

What it means

The block-info endpoint requires the id field to be a JSON string. The generic decoder would return a raw Go UnmarshalTypeError; this endpoint installs a custom decodeRequest that detects that case for string-typed fields and replaces it with the stable, human-readable message 'Field [id] should be of type [String]' for backward compatibility.

Solutions

1. Send id as a quoted JSON string: {"id":"20240101120000-abcdefg"}.
2. Coerce numeric-looking IDs to strings on the client before sending (String(id)).
3. Check where the ID originates (DB row, CSV) and ensure it is kept as text end-to-end.
4. If the error persists, print the raw request body to confirm the JSON type of id.

Example fix

// before
{"id": 20240101120000}
// after
{"id": "20240101120000-abcdefg"}

if (typeof payload.id !== "string") { payload.id = String(payload.id); }

const isBlockId = (v) => typeof v === "string" && v.length > 0;

try {
  await post("/api/block/getBlockInfo", {id});
} catch (e) {
  if (String(e.message).includes("Field [id] should be of type [String]")) {
    await post("/api/block/getBlockInfo", {id: String(id)});
  } else { throw e; }
}

When it happens

Trigger: POSTing to /api/block/getBlockInfo with {"id":12345} (numeric ID), {"id":true}, or an object/array instead of a quoted block ID string.

Common situations: Numeric IDs coming from databases or spreadsheet data, JS clients that strip quotes via template/eval mistakes, or copy-pasting a block ID that was accidentally coerced to a number (e.g. an all-digit ID in a weakly typed script).

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• Field [ ] should be of type [Array]
• Field [ ] should be of type [ ]
• Field [scope] should be of type [String]
• block ID must be text
• block is not a list item

AI-assisted analysis of siyuan-note/siyuan@9f775e8a12 (2026-09-19). Data as JSON: /api/errors/a56620899ca5330d. Report an issue: GitHub.

Appendix: source

Thrown at kernel/apicontract/block_info_decode.go:17

package apicontract

import (
	"encoding/json"
	"errors"
	"io"
	"reflect"
)

func init() {
	endpoint := GetBlockInfo
	GetBlockInfo.decodeRequest = func(reader io.Reader) (BlockInfoRequest, error) {
		request, err := endpoint.Decode(reader)
		var typeError *json.UnmarshalTypeError
		// 块信息入口保留 ID 类型错误的既有消息。
		if errors.As(err, &typeError) && typeError.Type.Kind() == reflect.String {
			return request, errors.New("Field [id] should be of type [String]")
		}
		return request, err
	}
}

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