sandbox-yaml

name	sandbox-yaml
description	Read and write YAML inside a Code node or CodeAct action, with js-yaml running in the guest

YAML in the sandbox

Specifier: @nodetool-ai/sandbox-yaml. One module, the js-yaml root export. Import it at the top of the body.

load — YAML text to a value

import yaml from "@nodetool-ai/sandbox-yaml";

const config = yaml.load(inputs.text);
return { name: config.name, replicas: config.replicas };

load reads one document and throws a YAMLException with a line and column on malformed input. Multi-document files go through loadAll, which returns an array.

dump — a value to YAML text

import yaml from "@nodetool-ai/sandbox-yaml";

return { text: yaml.dump({ name: inputs.name, tags: inputs.tags }, { indent: 2 }) };

dump throws on a cyclic structure unless you pass { noRefs: false }, and on a value it cannot represent (a function, a symbol).

Gotchas

• Everything runs in the guest. The 64 MB guest heap holds your input text, the parse tree, and the returned value at once. A file of a few megabytes is fine; a hundred megabytes is not.
• No timers, no I/O. The guest has no setTimeout, no filesystem, and no Node builtins. js-yaml needs none of them — that is why it is admitted — but code you write around it must not reach for them either.
• The safe schema is not the default. yaml.load uses DEFAULT_SCHEMA, which resolves tags such as !!timestamp. For input from a stranger, pass { schema: yaml.FAILSAFE_SCHEMA } and get strings, arrays, and objects only.
• This pack is the only route to YAML. There is no data.parseYaml global any more; every library the sandbox offers is an importable module, and this is the one for YAML. A node that needs it declares it.