getsops/sops · error

Could not unmarshal input data: %s

Error message

Could not unmarshal input data: %s

What it means

This error wraps any failure that occurs while parsing plaintext JSON input bytes into a sops.TreeBranches structure inside the JSON Store. The JSON store's LoadPlainFile feeds the raw bytes to treeBranchFromJSON, which uses encoding/json to decode into a tree; if the input is not valid JSON (or violates JSON value shapes), the underlying decoder error is surfaced wrapped with this message.

Source

Thrown at stores/json/store.go:338

		return sops.Tree{}, err
	}
	branches, metadata, err := stores.ExtractMetadata(branches, stores.MetadataOpts{
		Flatten: stores.MetadataFlattenNone,
	})
	if err != nil {
		return sops.Tree{}, err
	}
	return sops.Tree{
		Branches: branches,
		Metadata: metadata,
	}, nil
}

// LoadPlainFile loads plaintext json file bytes onto a sops.TreeBranches object
func (store *Store) LoadPlainFile(in []byte) (sops.TreeBranches, error) {
	branch, err := store.treeBranchFromJSON(in)
	if err != nil {
		return nil, fmt.Errorf("Could not unmarshal input data: %s", err)
	}
	return sops.TreeBranches{
		branch,
	}, nil
}

// EmitEncryptedFile returns the encrypted bytes of the json file corresponding to a
// sops.Tree runtime object
func (store *Store) EmitEncryptedFile(in sops.Tree) ([]byte, error) {
	branches, err := stores.SerializeMetadata(in, stores.MetadataOpts{
		Flatten: stores.MetadataFlattenNone,
	})
	if err != nil {
		return nil, fmt.Errorf("Error marshaling metadata: %s", err)
	}
	return store.EmitPlainFile(branches)
}

View on GitHub (pinned to 13442bb981)

Solutions

1. Validate the input with a JSON parser (e.g. `jq . file`) to see the exact syntax error location
2. Ensure the correct sops format/store is used: match --input-type/-i to the real file format (yaml, ini, env, json)
3. Strip BOM and encoding issues: re-save the file as clean UTF-8 without BOM
4. Fix the reported JSON syntax error in the file (the wrapped %s contains the Go json error with offset)

Example fix

// before: wrong store for content
store := json.NewStore()
tree, err := store.LoadPlainFile(yamlBytes) // "Could not unmarshal input data"
// after: use the store matching the content
store := yaml.NewStore()
tree, err := store.LoadPlainFile(yamlBytes)

func validateJSON(b []byte) error {
	b = bytes.TrimPrefix(b, []byte{0xEF, 0xBB, 0xBF}) // strip BOM
	if len(bytes.TrimSpace(b)) == 0 {
		return errors.New("empty input")
	}
	var v interface{}
	return json.Unmarshal(b, &v)
}
if err := validateJSON(input); err != nil {
	return fmt.Errorf("not valid JSON: %w", err)
}
tree, err := store.LoadPlainFile(input)

tree, err := store.LoadPlainFile(data)
if err != nil {
	if strings.HasPrefix(err.Error(), "Could not unmarshal input data") {
		return fmt.Errorf("input is not valid JSON: %w", err)
	}
	return err
}

When it happens

Trigger: Calling LoadPlainFile (or any higher-level path like LoadPlainData/decrypt workflows using the JSON store) with bytes that are not well-formed JSON: malformed syntax, trailing commas, comments, BOM bytes, empty input, or non-JSON binary data passed to the JSON store.

Common situations: Encrypting a file with the wrong format detection (e.g. a YAML file being processed by the JSON store), a .env or INI file passed to sops with --input-type json, corrupted downloads/partial writes of config files, or files starting with a UTF-8 BOM.

Understand the failure class

Background: "failed to unmarshal" / json.Unmarshal errors: why parsing a response into a Go struct fails and how to fix it — this error's family across 23 libraries.

Related errors

• failed to parse input as Bech32-encoded age public key: %w
• failed to parse input as age-ssh public key: %w
• Could not unmarshal config file: %s
• Could not unmarshal input data: %s
• Error marshaling to json: %s

AI-assisted analysis of getsops/sops@13442bb981 (2026-09-01). Data as JSON: /api/errors/32fa7974577dfb18. Report an issue: GitHub.