ENABLE_MCP_LARGE_OUTPUT_FILES
A Claude Code environment variable, read out of the shipped bundle. It has been in the build since v2.1.138, including the newest one read.
What it is
MCP_TOOL_TIMEOUT is parsed with a minimum of 1 and ENABLE_MCP_LARGE_OUTPUT_FILES only disables when explicitly false.
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.248.
Presence across releases
| Releases | Reading | Declared type | Default |
|---|---|---|---|
| 2.1.245 – 2.1.250 5 releases | never mined | — | — |
| 2.1.210 – 2.1.243 33 releases | in the build | triBool | — |
| 2.1.160 – 2.1.209 42 releases | in the build | bool | — |
| 2.1.138 – 2.1.159 20 releases | in the build | — | — |
A row reading never mined is a release with no archived bundle behind it. Nothing was read out of it, so nothing here says whether the name was in it. A declared type or a default is only ever what that release's own bundle stated.
Changelog entries naming it
-
v2.1.248MCP environment variables parsed once, with bounds
MCP_TOOL_TIMEOUT is parsed with a minimum of 1 and ENABLE_MCP_LARGE_OUTPUT_FILES only disables when explicitly false.
named in this entry
-
v2.1.248Turning off large MCP output files now requires an exact value
Only an exact false now disables large MCP output files; other values no longer switch it off.
named in this entry
Documentation pages
None of Anthropic's documentation pages this site has a copy of carries this name.
Names beside it
Every environment variable in the inventory starting enable, up to twelve of them.
ENABLE_BETA_TRACING_DETAILEDNo description from anybody. 2.1.138
ENABLE_CLAUDEAI_MCP_SERVERSNo description from anybody. 2.1.138
ENABLE_ENHANCED_TELEMETRY_BETANo description from anybody. 2.1.138
ENABLE_LOCKLESS_UPDATESNo description from anybody. 2.1.160
ENABLE_LSP_TOOLNo description from anybody. 2.1.160
ENABLE_PID_BASED_VERSION_LOCKINGNo description from anybody. 2.1.160
ENABLE_PROMPT_CACHING_1HNo description from anybody. 2.1.138
ENABLE_PROMPT_CACHING_1H_BEDROCKNo description from anybody. 2.1.138
ENABLE_SESSION_BACKGROUNDINGNo description from anybody. 2.1.160
ENABLE_SESSION_PERSISTENCENo description from anybody. 2.1.160
ENABLE_TOOL_SEARCHTool search now runs on Vertex AI instead of being refused outright. 2.1.138
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the environment variable does. All environment variables.