Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.251 Home All releases olderv2.1.250
Claude Code v2.1.251

Auto mode can skip the subagent-spawn prompt for URL-only Task prompts

You'll notice
Useful3 Signal3
Permissions

In auto mode, subagents whose prompt is only allowed URLs skip the spawn permission ask.

What

In Auto permission mode, launching a subagent whose entire prompt is just one or more URLs no longer raises the usual "Agent tool requires permission to spawn subagents" ask, provided every URL would already be allowed for WebFetch. Anything else about the prompt, and the normal prompt returns.

Details
  • Applies only when the session permission mode is auto ("dontAsk"); other modes are unaffected.
  • The prompt must be a string containing only URLs, up to a fixed count cap, and each URL is run through the WebFetch tool's own permission check.
  • It bails out if the agent type is not offered, or if the session already carries a permission denial record for it.
  • The call is tagged as pre-approved for the tool use so a later stage recognises it was cleared here.
  • One further disqualifying check exists but is hardcoded to return false, so it can never block this path in this build.
Evidence

typeof e !== "string" ||\n Bct() ||\n Eee()

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

See this entry in the whole of v2.1.251 →