Structured beta for the agent driving the tools.
betamatter is the YAML-frontmatter layer for MCP tool responses whose user
is the LLM. Every tool response has two channels — the body (the answer)
and the frontmatter (a trusted sidechannel about the answer) — and this
library owns the mechanics that keep that line honest: an entries container
(FMEntries) that guards multi-contributor guidance keys against silent
clobbering, the sole sanctioned --- block builder (build_frontmatter),
a box-drawing datamark fence for untrusted content (fence_content), and a
fire-once tip ledger (TipLedger) for once-per-process educational
guidance. Extracted from parkour-mcp,
whose frontmatter discipline it generalizes; consuming projects declare
their own trust polarity, field vocabulary, and tip registry as deltas.
The conventions themselves — handles/shape/steering, phrasing doctrine, trust rules, tip semantics — are specified in docs/standard.md.