tengu_speculation
A Claude Code feature flag, read out of the shipped bundle. No mined inventory carries it: everything below comes from what this site has written about it.
An analytics event, not a feature flag. Claude Code logs it when a speculation run (a forked agent run ahead on a suggestion) ends with outcome accepted, aborted or error. Fields include speculation_id, outcome, duration_ms, suggestion_length, tools_executed (successful tool results), completed and the boundary_type, boundary_tool and boundary_detail where it stopped, plus abort_reason or error_type, error_message and error_phase where they apply.
Not Anthropic's. Written by Claude Opus 5.5 from reading the v2.1.197 bundle, and it can be wrong.
In the changelogs
1Releases whose published page names tengu_speculation.
-
v2.1.7
Speculative Execution Infrastructure
gate cited by this entry, found in this entry's text
Gate readings
0No release here has a gate table behind it for this flag. Most published releases have none at all: the readings exist only for versions the pipeline captured flag state on.
First cited
0No release's published evidence quotes this name. The ledger indexes the Evidence lines of every changelog on this site, so this says nobody here has ever quoted it; it says nothing about how old the name is.
Presence across releases
0The miner has never read a build containing this name. It is here because a changelog entry of ours names it, which is evidence that it existed and not evidence of which releases carried it. The inventory starts at v2.1.138 and everything older than that was never mined.
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 feature flag does. All feature flags.