ipfs/kubo · error

unknown data field encoding

Error message

unknown data field encoding

What it means

ErrDataEncoding is a sentinel error exported by the deprecated `ipfs object` command family. The legacy `object` commands can render a DAG node's data field only in the encodings they know; when asked for an unknown data encoding they return this error. The whole ObjectCmd group is marked Deprecated in favor of `ipfs dag` and `ipfs files`.

Source

Thrown at core/commands/object/object.go:19

package objectcmd

import (
	"errors"

	cmds "github.com/ipfs/go-ipfs-cmds"
)

type Link struct {
	Name, Hash string
	Size       uint64
}

type Object struct {
	Hash  string `json:"Hash,omitempty"`
	Links []Link `json:"Links,omitempty"`
}

var ErrDataEncoding = errors.New("unknown data field encoding")

var ObjectCmd = &cmds.Command{
	Status: cmds.Deprecated, // https://github.com/ipfs/kubo/issues/7936
	Helptext: cmds.HelpText{
		Tagline: "Deprecated commands to interact with dag-pb objects. Use 'dag' or 'files' instead.",
		ShortDescription: `
'ipfs object' is a legacy plumbing command used to manipulate dag-pb objects
directly. Deprecated, use more modern 'ipfs dag' and 'ipfs files' instead.`,
	},

	Subcommands: map[string]*cmds.Command{
		"data":  RemovedObjectCmd,
		"diff":  ObjectDiffCmd,
		"get":   RemovedObjectCmd,
		"links": RemovedObjectCmd,
		"new":   RemovedObjectCmd,
		"patch": ObjectPatchCmd,
		"put":   RemovedObjectCmd,

View on GitHub (pinned to 329838acdf)

Solutions

1. Migrate to `ipfs dag get <cid>` (with --output-codec for format conversion) instead of `ipfs object`.
2. Use `ipfs files` / MFS commands for filesystem-style operations previously done via `ipfs object`.
3. If an encoding value was passed, correct it to one the legacy command accepts, or better, drop the deprecated call.

Example fix

// before
ipfs object get --data-encoding=bogus <cid>
// after
ipfs dag get <cid>            # or: ipfs dag get <cid> --output-codec=raw

// validate encoding against the set the legacy command supports before calling
var validEncodings = map[string]struct{}{"text": {}, "base64": {}}
if _, ok := validEncodings[encoding]; !ok {
    encoding = "base64" // or refuse
}

// err is the sentinel; compare directly, no unwrap needed
if err := cmd.Run(); err != nil && errors.Is(err, object.ErrDataEncoding) {
    // fall back to `ipfs dag get`
}

When it happens

Trigger: Calling a legacy object subcommand (e.g. `ipfs object get <cid>` variants that accept a data encoding option) with an unsupported encoding value; programmatically invoking the ObjectCmd tree with an invalid encoding argument.

Common situations: Users still on the deprecated `ipfs object` API (issue #7936) passing typos or encodings supported by newer `dag` tooling; scripts written against old kubo versions run on current ones.

Related errors

• can't convert non-dag-pb nodes to cidv0
• ErrNotDHT
• removed, use 'ipfs routing' instead
• %w: %v
• reading new root block: %w

AI-assisted analysis of ipfs/kubo@329838acdf (2026-09-03). Data as JSON: /api/errors/f3cc8f88ab0cad5f. Report an issue: GitHub.