Extension reference

vllm-sr/5.0 is systemone/0.2, the published System One standard, plus the fields below, extension set 5.0. Every vllm-sr message is a complete standard message: an extension field is an additive hint in its natural place, and a vllm-sr server answers an unknown field with 400 naming it.

The last column says what the Router does with the field when the target deployment speaks systemone/0.2: it strips a field the standard part of the message already expresses, refuses at load a rule that needs one the standard cannot carry, and never expects a response field.

Request

Field	Type	Since	Families	On systemone/0.2	Description
roles	object of user or context or answer	5.0	vela2, vela3, vela3_d3	stripped	Which state keys hold the user's content, context, or the answer under check. Role-aware families read the state's parts by these roles; without roles, the whole state is the user's content on every family.
options	object	5.0	all	stripped	deadline_ms (work not started by then is not run, and its questions answer deadline_exceeded), return_meta (the response adds meta) and max_tokens (the scan budget of a model that reads a long part in windows). A standard target is bounded by the client's own timeout instead.

Question

Field	Type	Since	Families	On systemone/0.2	Description
preset	string	5.0	decision1, vela2, vela3, vela3_d3	stripped	A question the model was trained on, such as pii, answered by its trained head. The question still carries its own instructions and criteria, which any other server answers.
head (span)	router or broad	5.0	vela2, vela3, vela3_d3	refused at load	The span head that answers: router, or broad on models that have a broad span head.
decision_adapter (choice, noul, score)	boolean	5.0	vela3_d3	refused at load	Answers with the package's opt-in decision adapter, on Vela 3.0 d3 sizes that declare one.
over	string or array of string	5.0	vela2, vela3, vela3_d3	refused at load	The state keys the question reads, in state order; by default the whole state (a span: its answer part if present, else its user part).
overflow	window or truncate	5.0	vela2, vela3, vela3_d3	stripped	How a model with a scan budget reads a part longer than one input: window (whole, in windows) or truncate (its first tokens).
require_full_input	boolean	5.0	all	refused at load	Fails the question unless every state part is read completely; its answer then carries input_coverage: complete, which the standard has no field for.
threshold (set, span)	number	5.0	vela2, vela3, vela3_d3	refused at load	Replaces the model's decision threshold for a set or span question; the applied value comes back in thresholds.
at (box)	number	5.0	decision3, vela3_d3	refused at load	A box question on a video: the second to read, from the start of the state's only video.
rate (track)	1 or 2	5.0	decision3, vela3_d3	refused at load	A track question's updates per second over the whole video, 1 (the default) or 2.

Question type

Field	Type	Since	Families	On systemone/0.2	Description
span	object	5.0	vela2, vela3, vela3_d3	refused at load	Where each label of criteria occurs in the text it reads. The answer is a noul (the highest probability any word reached) and its spans under spans.
set	object	5.0	vela2, vela3	refused at load	Which labels of criteria apply, each with its own probability, under sets; each label also answers as a noul under <question>.<label>.
track	object	5.0	decision3, vela3_d3	refused at load	A box for each sampled moment of the state's only video, on models whose card declares track questions.

Asset type

Field	Type	Since	Families	On systemone/0.2	Description
video	object	5.0	decision3, vela3_d3	refused at load	A video, placed where its placeholder is, on models whose card lists the video modality.

Answer

Field	Type	Since	Families	On systemone/0.2	Description
abstain_probability (choice, noul)	number	5.0	vela2, vela3	never sent	The probability of the model's abstain option, where it has one (not calibrated).
input_coverage	complete	5.0	all	never sent	Proof that a require_full_input question read every state part completely.
error	invalid_question or invalid_input or max_length_exceeded or scan_budget_exceeded or invalid_model_output or deadline_exceeded or unavailable	5.0	all	never sent	Why this question has no answer, on POST /v1/decisions, which answers the other questions in the same 200.
reason	string	5.0	all	never sent	A fixed word for why the question failed; it never carries request data.
message	string	5.0	all	never sent	Why the question failed, for a person to read.

Response

Field	Type	Since	Families	On systemone/0.2	Description
spans	object of array of object	5.0	vela2, vela3, vela3_d3	never sent	Each span question's spans: label, start and end (Unicode code points into the text it read, end exclusive), text and probability.
sets	object of object	5.0	vela2, vela3	never sent	Each set question's selected labels and the probability of every label.
thresholds	object of number	5.0	vela2, vela3, vela3_d3	never sent	The threshold applied to each set or span question.
span_heads	object of router or broad	5.0	vela2	never sent	The span head that answered each span question, on models with a broad span head.
meta	object	5.0	all	never sent	With options.return_meta, the model's verified identity, revision, precision, numerics, engine, device and timings.
routing	object	5.0	the Router	never sent	Added by the Router's vllm-sr/auto routing: the recipe, decision, algorithm, stage and model that answered, and the model calls made.

Error

Field	Type	Since	Families	On systemone/0.2	Description
code	string	5.0	all	never sent	A stable error code beside the standard detail, such as invalid_request, model_not_found, overloaded or question_failed.
question	string	5.0	all	never sent	The question whose failure answers the request (question_failed).
state	string	5.0	all	never sent	In a batch, the name of the request the failed question belongs to.
reason	string	5.0	all	never sent	A fixed word for why the request or its question failed; it never carries request data.
limit	integer	5.0	all	never sent	The limit reason names, when one was broken (bytes, pixels, seconds or tokens).

Listing entry

Field	Type	Since	Families	On systemone/0.2	Description
version	string	5.0	all	never sent	The extension set version the server answers with, such as 5.0.
features	array of string	5.0	all	never sent	The question types and extension features the model answers, which vllm-sr/auto routes by.
card	object	5.0	all	never sent	The model card, with its limits and placement.

Endpoint

Endpoint	Since	Families	Description
POST /v1/systemone/batch	5.0	all	Named standard requests answered in one call, each as it would be alone. An item takes the batch's model and may repeat it. A systemone/0.2 target has no batch endpoint, so a batch is split into single requests.
POST /v1/decisions	5.0	all	The body of POST /v1/systemone, answered with a failed question's error, reason and message in its own answer of a 200, instead of failing the request.
GET /health	5.0	all	Readiness, with the extension set version the server answers with.

Removed forms

The model runtime contract 4.0.0 accepted these forms; the standard expresses them, so 5.0 answers them with 400 naming the replacement.

Form	Level	Replaced by	Note
choices	question	criteria	An object of option keys to descriptions, for choice and noul.
levels	question	criteria	An ordered array of level descriptions, for score.
labels	question	criteria	An object of labels to descriptions, for set and span.
images	request	assets	Assets of type image, placed by their placeholders.
videos	request	assets	Assets of type video.
states	request	POST /v1/systemone/batch	/v1/systemone takes exactly one request.
long_context	options	TypeSafe-Danger-Zone-Long-Context: true	The standard's request header.
error	error	detail	The standard detail, with flat code, question, state, reason and limit.
data	listing	models[].card	Router mode keeps the OpenAI data list for Chat clients.
implicit roles	state	roles	State keys carry no meaning; roles names the parts.