{"version":"2.1.321","anchor":"bash-tool-result-field-backgroundcalledbackwithinms-permiss","canonical_anchor":"bash-tool-result-field-backgroundcalledbackwithinms-permiss","heading":"Background command timing field and fresher permission rule checks","tier":"internal","area":"Bash","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.321\/e\/bash-tool-result-field-backgroundcalledbackwithinms-permiss","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.321","markdown":"### Background command timing field and fresher permission rule checks\n\nCommand results gain a field about when a background command reports back, and saved permission rule matches are rechecked when stale\n\n**Unclear.** It is not known whether the field is ever filled in.\n\n**What**\n\nResults from the Bash tool, which runs shell commands, can now include a `backgroundCalledBackWithinMs` field. A background command keeps running while Claude Code carries on with other work.\n\nClaude Code also remembers which permission rules match which files, and now rechecks those saved matches when they may be out of date. This includes shortcut files that point to another file.\n\n**Why**\n\nThe new field tells the model when a background command will report back.\n\n- Area: Bash\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 2\/5\n- Scope: individual\n- Heads-up: no"}