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 v2.1.248 Home All releases olderv2.1.247 v2.1.250newer
Claude Code v2.1.248

MCP output token cap resolution

Use it now
Useful2 Signal1
MCP not in their notes

MAX_MCP_OUTPUT_TOKENS is still honoured first, but it's no longer sanity-checked as a number.

Feature flag
tengu_velvet_ibis Not enough to say

Nothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.

This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.248: not a boolean we can read

Read once, for one account on one subscription tier, against v2.1.248. It isn't a statement about your account. What a flag value here can and cannot tell you

MAX_MCP_OUTPUT_TOKENS
What

The limit on how much output an MCP tool may return still reads the MAX_MCP_OUTPUT_TOKENS environment variable first, then a server-side config value, then a built-in default. The environment value is no longer checked for being a finite number before use.

Details
  • Server config comes from tengu_velvet_ibis, whose fallback is an empty object, so with no server value the built-in default applies.
Evidence

tengu_velvet_ibis

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

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.1.248 →