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 v2.1.228 Home All releases olderv2.1.227 v2.1.229newer
Claude Code v2.1.228

Write-before-Read rule is now decided locally, not by a remote flag

You'll notice
Useful4 Signal4
Permissions Notable

Writing a file you have not read is now decided locally by model and permissions, not a server flag.

Feature flag
tengu_velvet_mallet Off in both readings

The flag server returned off for the account this site reads and for the anonymous baseline. A reading of off cannot rule out a rollout these two readings sit outside of.

This account: off · anonymous baseline: off · compiled default in v2.1.228: not a boolean we can read

These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.

Read once, for one account on one subscription tier, against v2.1.228. It isn't a statement about your account. What a flag value here can and cannot tell you

What

Whether Write may touch a file you have not read was previously switched by a server-side flag; that flag is gone from the build and the rule is now fixed in the client. Writing without a prior Read is allowed only for non-.ipynb files, only for models outside a listed set (including claude-opus-4-5 and claude-sonnet-4-5), and only when reading that path is already auto-allowed by your permission rules. A file you read only as a partial view now always triggers the error.

Details
  • The removed remote flag was tengu_velvet_mallet; nothing in the build reads it any more, so behaviour no longer varies by server config.
  • Notebook files are excluded outright, so .ipynb writes always require a real Read first.
  • If reading the path would itself prompt for permission, the exemption does not apply.
Evidence

File has not been read yet. Read it first before writing to it.

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

See this entry in the whole of v2.1.228 →