The 182 the cap is chosen against had no direct case: the existing tests
cover the root chain and the TypedDict field, both of which start one
bracket lower. An array-rooted parameters schema reaches it from a plain
ToolSdkSchema literal, no raw register() needed. Exactly 180 arrays over
a const scalar is the worst case itself -- the root frame starts at
listDepth 0, so every list[ still emits and the innermost Literal[ is
reached rather than degraded; one deeper is where the item degrades.
Name the subscript tool-name comment in pyScalar's docstring: it quotes
through the same JSON.stringify call and inherits the same escapes and
the same pass-throughs.
pyScalar's docstring named only the two code points CPython refuses
anywhere in source. A bare quote, a trailing odd backslash, and a bare
LF/CR break the Literal line just as fatally, and JSON.stringify is what
covers those too. The argument also leaned on an unstated coincidence:
every escape JSON.stringify can emit is a Python escape for the same
character, which is why the emitted text both parses and decodes back to
the declared value. Say both, and assert the second class.
"statement head" does not describe `case`, whose clause block is not a
statement. Split the positions three ways.
Add the mode 'both' by python assembly, pinning the mode-by-language
matrix rather than leaving it to the shared code path.
trim and escape commute for every input, so the new whitespace test does
not pin their order: UNPRINTABLE and LONE_SURROGATE are disjoint from the
set trim() strips, and both escapes emit plain non-whitespace ASCII,
leaving the leading and trailing whitespace runs byte-identical. State that instead of the false causal clause.
pyScalar's Literal path escapes nothing itself -- JSON.stringify is what
keeps it parseable, covering NUL and, under ES2019 well-formed
stringification, unpaired surrogates. Record the dependency and turn it
into a checked invariant. Pin the docstring emission site for a lone
surrogate too, mirroring the NUL case.
Two docstring corrections: describe's caller enumeration omitted the
synthetic { description } wrapper docLines builds, and "special in
statement position" does not describe `_`, which is special in a match
pattern. Both keep the conclusion they support.
Note which of the two table guards fires depends on the entry point.
U+00AD is 0xAD, so "Cf cannot be addressed by \xNN" was false for the
first example in its own list. The real boundary is the category: one
\xNN form covers Cc exactly, and escaping the single addressable Cf
member would leave a rule that is neither category- nor
addressability-shaped.
A lone surrogate is the NUL case rather than the invisible-character
case -- Python source must be UTF-8-encodable, and compile() raises
UnicodeEncodeError for one in a string literal or a # comment alike
(measured on 3.9). JSON.parse on a wire "\ud800" escape produces them,
so escape them as \uNNNN; the regex's u flag keeps well-formed astral
pairs intact.
Pin the whitespace-plus-surviving-control boundary, which also pins
trim-after-escape.
Unicode Cc is U+0000-U+001F plus U+007F-U+009F, and no C1 code point is
ECMAScript whitespace, so U+0080-U+009F all survived the collapse and
reached the docstring raw and invisible -- the gap the previous commit
closed for NEL alone. \xNN addresses the whole block, which is the same
reason the set stops at Cc, so widen the class to U+009F and pin
U+009B/U+009C/U+009F.
Windows-1252 bytes 0x80-0x9F decoded as Latin-1 produce exactly these.
Also: required TypedDict fields share the optional fields' listDepth
start, and a description of whitespace plus a surviving control
character is not absent.
The static-stub sentence over-generalized: `tools` and `ToolCallError`
ARE bound at run time, and a model reading "everything below is a stub"
could stop catching `ToolCallError`. State the boundary and pin both
halves in the fixed-instruction assertions.
UNPRINTABLE missed U+0085: it is Cc but not ECMAScript whitespace, so
it survived the collapse and reached the docstring raw and invisible.
Add it and scope the docstring to Cc, since the `\xNN` escape cannot
address the Cf formatting characters that pass through by design.
Record the backend PR's two runtime contracts -- inject only `tools`
and `ToolCallError`, and bind the assembly-time language to the
request -- in the Agent Note and at requireCodeRuntime.
- `relay` resolves its sender in `contextBody` like every other form. It was
the one shape whose marker could claim a form the body did not render: an
unreadable sender fell back inside the body while the row still said relay,
contradicting the contract this PR's own note states.
- `recall` requires the retained, omitted, and truncated fields. Completeness
is what the card exists to report, so a reference that cannot state it is
not a readable recall — showing the label alone presents a confident card
over unknown loss.
- The snapshot body states the supersession its producer framing line carries.
That line is the one part of the model-facing text no section contains, and
unlike an instruction context's `<system-reminder>` it states the form's own
semantics rather than wrapping content.
- `GoalMessageSource` is a discriminated pair, so `{ form: 'notice' }` without
its account no longer compiles. The guarantee this PR claims now holds at
that seam too, not only through `ContextFormed` on plugin sources.
- Goal and tool-goal summaries are bounded by a shared `boundContextSummary`,
which tool-tasks now uses as well. A goal objective is unbounded caller text
in exactly the way a task label is.
- The runtime snapshot interpolates once per request: agent-loop renders the
sections and joins them through `joinContextSections`.
- Every form's fallback branch is pinned, not only the notice one.
A TypedDict reads as a constructible class, so a model that writes
FooArgs(field=1) fails with NameError before dispatch: the run request
injects only the tools namespace and ToolCallError. Say so in
SDK_INSTRUCTIONS and require plain dict/list JSON arguments. The TS
flavor needs no counterpart -- interface is visibly a type and its
"runs type-stripped" clause already covers erasure.
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.
