Four values complete the vocabulary, so the opaque body is reached only by
producers that genuinely promise no shape.
`snapshot` — current state a later snapshot supersedes. system-prompt now
exposes `renderContextSections()`, the named contributions
`renderContextSnapshot()` already joins for the model, so the body attributes
each part to the subsystem that produced it instead of re-splitting joined
prose. The runtime snapshot, time-context, and tmux-context declare it.
`notice` — a one-off account of what just happened, declared by tool-tasks,
goal state changes, tool-goal wrap-up, plan-mode switches, and
repeat-tool-guard. Its `summary` rides the COLLAPSED row: these five are the
majority of shipped producers and none of them needs expanding to be read.
The task summary bounds itself because its inputs are unbounded caller text.
`relay` — a message another agent addressed to this one; both subagent
sources declare it and the body names the sender above what it said.
`recall` — material lifted from another session's log. session-reference
needed no new field: its references already record retained and omitted
counts and the truncation flag, which the body shows first, because recalled
context is bounded on the way in.
`ContextFormed` is now discriminated by `form`, so a producer cannot declare
a shape without the facts that shape is presented from — a notice without its
summary, or a snapshot without its sections, fails to compile.
Only the two hook bridges stay opaque, by design: their content is whatever
an external program printed, so no shape can be promised for it. Unknown
kinds and unreadable records land there too.
The list-nesting cap guards against a tokenizer SyntaxError, which makes the
text not Python. A long `A | B | …` union is valid at any length and only
defeats CPython's compile-time C recursion (measured: 1,000 branches compile,
5,000 raise RecursionError); nothing compiles this block, and capping would
retire the deep-chain tests pinning the walk's linear time. Records that
boundary at the `oneOf` arm and in the Agent Note (both languages).
Also documents that the context-free degrade marker reads the call's
className rather than the frame's — frames propagate a derived name, so a
per-frame read would declare classes the caller cannot receive — and pins
that path with oneOf-of-objects and array-of-oneOf assertions.
A schema nesting arrays past ~200 levels rendered a `list[list[...]]` chain
CPython's tokenizer rejects outright (`too many nested parentheses`), so the
SDK block was not valid Python at all — the failure docstring escaping in the
same file already guards against. The chain now degrades to `Any` at 180
levels; nesting restarts per TypedDict field, since a field annotation is its
own logical line. Unions and nested objects are unaffected: neither
accumulates open brackets.
Also aligns the unreachable SDK_RENDERERS guard message with the two reachable
ones, and corrects a test comment that still said class docstring.
A description was emitted above the `async def`, where Python treats the
first string as the `Tools` class docstring and every later one as a dead
expression — leaving each method undocumented in the model's only source of
tool semantics. Emit it as the first statement of the method body instead.
Also names the known languages in the run_code flavor guard (the reachable
rejection, symmetric with the SDK_RENDERERS guard) and corrects three doc
claims: the code-runtime group README no longer calls the generated SDK
TypeScript, the base Code Mode note states its serial dispatch in past
tense, and the tools README points at the rationale the language-dispatch
note actually carries.
Assistant footers and the stats line gain TTFT/tok-per-second readings
folded from step timings; context occupancy moves off the stats line onto
a composer ring whose panel shows a heuristic system/tools/messages
breakdown from the new token-meter contextBreakdown session projection.
The Python renderer partitioned identifier methods ahead of subscript
comments, so a tool set like {a-tool, z} emitted z first — contradicting
the documented lexicographic contract and the TypeScript flavor, which
quotes exotic keys in place. Interleave both kinds in one ordered stream
and track emitted statements for the pass fallback.
Also correct four stale serialization claims in the base Code Mode note
that the live-parallel scheduler superseded.
- turn boundary now returns false for an empty admitted batch (claimed
input removed before the wake) instead of opening a turn and spending a
model call on nothing; the step boundary already had the symmetric guard.
- a max-token step stays sticky when steering or injected work continues
the turn: a later completed step no longer downgrades the outcome,
matching the TurnEndReasonMap contract.
- session/queue wire schema accepts the context placement (previously the
zod union rejected injected-context snapshots wholesale and the client
silently dropped the whole frame); schema tests cover all placements.
- headless runs settle at whole-agent idle instead of the first turn/end,
honoring the one-shot idle-to-idle contract.
- flush JSDoc names the real callers (checkpoint policy, goal-session,
teardown, self-flushing consumers); apiproxy zh README loses its stale
duplicate history section; ACP note/README record the delivered error
rejection and turnless-cancelled behaviors.
Appending todo/write, request/header, and request/context inside an open
turn now exercises the switch cases and the enclosed-branch of the
invariant, closing the last branch gap.