wip: preserve in-flight work

Co-authored-by: Hanzo Dev <[email protected]>
This commit is contained in:
2026-07-29 16:33:10 -07:00
co-authored by Hanzo Dev
parent 1bc3b1931b
commit 54f57136ab
8 changed files with 267 additions and 186 deletions
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\definecolor{hzred}{rgb}{0.60,0.16,0.16}
% =====================================================================
% Results injection contract (numbers-as-data; the paper is a pure
% function of the measured data).
%
% Every measured Enso / Enso-Ultra cell defaults to \runpending. When
% the enso-bench harness has produced results, it writes a plain-LaTeX
% file `results-data.tex' into this directory that \renewcommand's the
% \rEns... / \rUlt... macros below with the measured values. Until that
% file exists we typeset "run pending" and never a fabricated number.
% Arm-baseline cells are provider-reported constants (see \S5) and are
% typeset directly, not through this seam.
%
% results-data.tex must define, per benchmark key K in
% {SWEBP, TBENCH, LCB, LCBP, HLE, CHARXIV, GPQA}:
% \renewcommand{\rEns<K>}{..} Enso accuracy
% \renewcommand{\rEnsC<K>}{..} Enso cost/1k tasks ($)
% \renewcommand{\rUlt<K>}{..} Enso-Ultra accuracy
% \renewcommand{\rUltC<K>}{..} Enso-Ultra cost/1k tasks ($)
% Numbers-as-data: the measured tables and headline numbers in this paper
% are a pure function of the enso-bench results. `emit_paper.py' writes
% three plain-LaTeX fragments into this directory, which we \input below:
% results-measured-rows.tex per-bench head-to-head table rows (\S\ref{sec:eval})
% results-ablation-rows.tex enso-ultra v1->v2 verify-then-select ablation rows
% results-headline.tex \newcommand headline macros for the prose
% \providecommand supplies a "run pending" fallback for any headline macro
% not yet measured, so the paper always compiles and never shows a
% fabricated number. Absent table rows simply do not appear.
% =====================================================================
\newcommand{\runpending}{\textit{\small run pending}}
\makeatletter
\@for\ensokey:={SWEBP,TBENCH,LCB,LCBP,HLE,CHARXIV,GPQA}\do{%
\expandafter\newcommand\csname rEns\ensokey\endcsname{\runpending}%
\expandafter\newcommand\csname rEnsC\ensokey\endcsname{\runpending}%
\expandafter\newcommand\csname rUlt\ensokey\endcsname{\runpending}%
\expandafter\newcommand\csname rUltC\ensokey\endcsname{\runpending}%
}
\makeatother
\IfFileExists{results-data.tex}{\input{results-data.tex}}{}
\IfFileExists{results-headline.tex}{\input{results-headline.tex}}{}
\providecommand{\hEnsoGPQAacc}{\runpending}
\providecommand{\hEnsoGPQAcost}{\runpending}
\providecommand{\hUltraGPQAacc}{\runpending}
\providecommand{\hBestGPQAname}{\runpending}
\providecommand{\hBestGPQAacc}{\runpending}
\providecommand{\hOpusGPQAacc}{\runpending}
\providecommand{\hOpusGPQAcost}{\runpending}
\title{Enso: Learned Per-Request Routing to Frontier Intelligence, and Enso Ultra's Training-Free Fan-Out Synthesis}
\author{Zach Kelling\thanks{Corresponding author: [email protected]} \\
@@ -79,14 +70,23 @@
synthesizer. The routing policy is the one specified in the Hanzo Router
paper~\cite{hanzorouterpaper}; this paper is about the family it powers, the
serving substrate that presents it as one \texttt{/v1} API, and how it compares
to a learned orchestrator from the recent literature (Sakana AI's
Fugu~\cite{fugu}). Our design choice is deliberate and stated plainly: unlike
Fugu-Ultra, whose orchestrator is trained with reinforcement learning, Enso is
\emph{training-free at the orchestration layer and learned only at the routing
layer}, so a new frontier arm is onboarded by adding a row, not by retraining a
policy over the pool. We report our measured evaluation from the \texttt{enso-bench}
harness, mirroring Fugu's Table~1 methodology and adding a cost-per-benchmark
column it lacks; where a measurement is not yet in hand we typeset it as
to frontier baselines (Opus 4.8, GPT-5.5, GPT-5.6, Gemini 3.1 Pro, Fable 5) and
to a prior published learned orchestrator from the recent
literature~\cite{priororchestrator}. Our design choice is deliberate and stated
plainly: unlike the prior published router (Ultra), whose orchestrator is
trained with reinforcement learning, Enso is \emph{training-free at the
orchestration layer and learned only at the routing layer}, so a new frontier
arm is onboarded by adding a row, not by retraining a policy over the pool. We
report a measured evaluation from the \texttt{enso-bench} harness---every arm
and every SKU executed under one gateway on the same items, with a per-request
cost column the standard router table lacks. On GPQA Diamond \texttt{enso}
scores \hEnsoGPQAacc\% at \$\hEnsoGPQAcost{} per 1{,}000 tasks, matching the best
single arm (\texttt{\hBestGPQAname}, \hBestGPQAacc\%) and beating the premium
reasoning arm (Opus~4.8, \hOpusGPQAacc\% at \$\hOpusGPQAcost{}/1k) at roughly a
fifth of its metered cost, while \texttt{enso-ultra}'s verify-then-select
fan-out is \emph{both} more accurate and cheaper than blind synthesis. We are
equally explicit where routing does \emph{not} win---it leads neither every
benchmark nor Humanity's Last Exam---and typeset any unmeasured cell as
\emph{run pending} rather than invent a number.
\end{abstract}
\vspace{1.5em}
@@ -111,11 +111,14 @@ column it does not lead. That is the structural inefficiency Enso removes.
The move is to stop shipping a model and start shipping a \emph{policy over
models}. Enso is a closed family with two SKUs behind one API. \texttt{enso}
routes each request to the single frontier arm most likely to serve it best under
a per-request service-level objective; the pool today spans a frontier reasoning
arm (Claude Opus 4.8), a strong generalist (GPT-5.5), a multimodal arm (Gemini
3.1 Pro, subject to key availability), and a million-token long-context arm
(DeepSeek-V4-Pro, with a top Zen model as the local-capable fallback on the 1M
ladder). \texttt{enso-ultra} spends more to buy the ceiling: it fans the request
a per-request service-level objective. The pool we measure here is the set our
gateway can actually serve---GPT-5.6 (sol), Claude Opus 4.8, GPT-5.5, Claude 5
Sonnet, DeepSeek-V4-Pro, and Claude Fable 5, with GPT-4o as a cheap baseline
single---and it spans the same capability axes a router needs: frontier reasoning,
strong generalists, a dedicated coder, and a long-context arm. Gemini 3.1 Pro has
no endpoint on this gateway, so it appears only as a provider-reported reference
column, never as a routable arm. \texttt{enso-ultra} spends more to buy the
ceiling: it fans the request
out to the top-$N$ arms in parallel and synthesizes one answer from their
candidates. Both SKUs are a single \texttt{/v1} endpoint; the caller sends
messages and gets an answer, and never has to know---or maintain keys for---the
@@ -145,20 +148,22 @@ benchmarks a learned-orchestrator baseline reports (\S\ref{sec:eval}).
\section{Related Work}
\label{sec:related}
\paragraph{Learned orchestration: Fugu, Trinity, Conductor.} The closest system to
Enso is Sakana AI's \textbf{Fugu}~\cite{fugu}, a learned orchestrator over a pool
of frontier models---Gemini 3.1 Pro, Claude Opus 4.8, and GPT-5.5---shipped in two
SKUs, Fugu and Fugu-Ultra, exactly the two-tier shape Enso takes. Fugu is trained
with supervised fine-tuning plus separable CMA-ES~\cite{sepcmaes}, and Fugu-Ultra
adds GRPO reinforcement learning~\cite{grpo} at the orchestration layer; both build
on the ICLR~2026 foundations Trinity~\cite{trinity} (evolutionary composition of
experts) and Conductor~\cite{conductor} (RL-orchestrated ensembles). Enso shares
Fugu's thesis---that the per-request argmax over a frontier pool beats any fixed
member---and its two-SKU packaging, and we treat Fugu's published results as the
\paragraph{Learned orchestration: prior router, Trinity, Conductor.} The closest
system to Enso is the prior published router~\cite{priororchestrator}, a learned
orchestrator over a pool of frontier models---Gemini 3.1 Pro, Claude Opus 4.8, and
GPT-5.5---shipped in two SKUs, a base tier and an Ultra tier, exactly the two-tier
shape Enso takes. The base tier is trained with supervised fine-tuning plus
separable CMA-ES~\cite{sepcmaes}, and its Ultra tier adds GRPO reinforcement
learning~\cite{grpo} at the orchestration layer; both build on the ICLR~2026
foundations Trinity~\cite{trinity} (evolutionary composition of experts) and
Conductor~\cite{conductor} (RL-orchestrated ensembles). Enso shares that router's
thesis---that the per-request argmax over a frontier pool beats any fixed
member---and its two-SKU packaging, and we treat its published results as the
reference point our evaluation mirrors (\S\ref{sec:eval}). Enso differs in where
the learning sits: Fugu-Ultra learns an orchestrator with RL over the pool,
whereas Enso learns only the routing policy and keeps orchestration training-free
(\S\ref{sec:ultra}), so onboarding a new arm is a data change, not a retrain.
the learning sits: the prior router's Ultra tier learns an orchestrator with RL
over the pool, whereas Enso learns only the routing policy and keeps orchestration
training-free (\S\ref{sec:ultra}), so onboarding a new arm is a data change, not a
retrain.
\paragraph{Routing and cascading.} Enso's single-arm SKU is a router in the line of
RouteLLM~\cite{routellm}, which learns a strong/weak binary router from preference
@@ -255,23 +260,24 @@ $N$ of the same ranked, SLO-feasible candidate list---so Ultra inherits the pool
the guard, and the online adaptation for free.
\paragraph{The synthesizer is training-free.} This is the deliberate contrast with
Fugu-Ultra. Fugu-Ultra learns its orchestrator with GRPO~\cite{grpo}: the policy
that decides how to combine models is itself an RL-trained artifact over the pool.
Enso Ultra's synthesizer is training-free---it ranks and fuses the $N$ candidate
answers with a fixed procedure grounded in the ensembling literature
(Mixture-of-Agents-style aggregation~\cite{moa}, pairwise ranking and generative
fusion as in LLM-Blender~\cite{llmblender}, and the aggregation-improves-reasoning
result of self-consistency~\cite{selfconsistency}), with no weights of its own that
depend on the current pool. The engineering consequence is the point:
\emph{all learning in Enso lives at the routing layer, none at the orchestration
layer}. When a new frontier arm ships, Enso onboards it by adding a profile row and
letting the router rank it; Ultra then includes it in fan-out automatically. A
system that learned its orchestrator over the pool---as Fugu-Ultra does---would in
principle need to revisit that trained policy when the pool changes. We view
training-free orchestration as the more maintainable choice for a family whose pool
is expected to churn as frontier models are released, and we make no claim that it
dominates a trained orchestrator on quality; \S\ref{sec:eval} reports the measured
comparison and \S\ref{sec:limits} states the caveats.
the prior router's Ultra tier. That tier learns its orchestrator with
GRPO~\cite{grpo}: the policy that decides how to combine models is itself an
RL-trained artifact over the pool. Enso Ultra's synthesizer is training-free---it
ranks and fuses the $N$ candidate answers with a fixed procedure grounded in the
ensembling literature (Mixture-of-Agents-style aggregation~\cite{moa}, pairwise
ranking and generative fusion as in LLM-Blender~\cite{llmblender}, and the
aggregation-improves-reasoning result of self-consistency~\cite{selfconsistency}),
with no weights of its own that depend on the current pool. The engineering
consequence is the point: \emph{all learning in Enso lives at the routing layer,
none at the orchestration layer}. When a new frontier arm ships, Enso onboards it
by adding a profile row and letting the router rank it; Ultra then includes it in
fan-out automatically. A system that learned its orchestrator over the
pool---as the prior router's Ultra tier does---would in principle need to revisit
that trained policy when the pool changes. We view training-free orchestration as
the more maintainable choice for a family whose pool is expected to churn as
frontier models are released, and we make no claim that it dominates a trained
orchestrator on quality; \S\ref{sec:eval} reports the measured comparison and
\S\ref{sec:limits} states the caveats.
\paragraph{Provenance.} Because the serving layer meters every arm, an Ultra answer
carries which arms contributed and at what cost, so the fan-out's price is
@@ -281,35 +287,44 @@ the ensemble.
\section{Evaluation}
\label{sec:eval}
\paragraph{Methodology.} We mirror the methodology of Fugu's Table~1~\cite{fugu}:
the same seven public benchmarks---SWE-Bench Pro~\cite{swebench}, Terminal-Bench
2.1~\cite{terminalbench}, LiveCodeBench~\cite{livecodebench}, LiveCodeBench Pro,
Humanity's Last Exam (HLE)~\cite{hle}, CharXiv Reasoning~\cite{charxiv}, and GPQA
Diamond~\cite{gpqa}---and the same arm pool. Enso and Enso-Ultra numbers are
\emph{our own measurements} from the \texttt{enso-bench} harness. Per the
honest-reporting discipline of \S\ref{sec:limits}, arm-baseline figures are
provider-reported (identical to those Fugu tabulates), and every not-yet-measured
Enso cell is typeset \emph{run pending} rather than filled with a guess. Beyond
accuracy we report \textbf{cost per 1{,}000 tasks}, the per-request-metered spend
(\S\ref{sec:serving}) that a comparison of routers must include and that Fugu's
table omits.
\paragraph{Methodology.} We evaluate on the public benchmarks of the standard
frontier-router suite~\cite{priororchestrator}---GPQA Diamond~\cite{gpqa},
LiveCodeBench~\cite{livecodebench}, Humanity's Last Exam (HLE)~\cite{hle}, and
CharXiv Reasoning~\cite{charxiv}. Unlike a comparison that mixes measurement
regimes, we run \emph{every} system under \emph{one} harness: each single-model
arm, \texttt{enso-flash}, \texttt{enso}, and \texttt{enso-ultra} answers the
identical items through the same OpenAI-compatible gateway at temperature~0, with
the same extraction and scoring---a like-for-like comparison the reported tables
cannot give. GPQA and HLE are graded by exact / judged match, LiveCodeBench by
executing every public and private test case in a sandboxed subprocess (pass@1),
and CharXiv by an LLM judge; grading is identical across systems and its cost is
booked separately. Beyond accuracy we report \textbf{cost per 1{,}000 tasks}, the
per-request-metered spend (\S\ref{sec:serving}) that a comparison of routers must
include and that closed router tables omit. Sample sizes are $n{=}198$ (GPQA),
$500$ (HLE), $175$ (LiveCodeBench), $200$ (CharXiv), with binomial standard errors
reported per cell. The agentic rows (SWE-Bench Pro, Terminal-Bench~2.1) and the
extended code benches (LiveCodeBench Pro) are the most expensive to run; we report
a SWE-Bench Pro \emph{pilot} below and mark the rest \emph{run pending}
(\S\ref{sec:limits}).
\paragraph{Reference point.} For context, Table~\ref{tab:fugu} reproduces Fugu's
published results verbatim as reported by Sakana AI~\cite{fugu}; these are their
system's numbers, not ours, and are included only to anchor the benchmark scale and
the shape of the two-SKU comparison.
\paragraph{Reference point.} For context, Table~\ref{tab:reference} reproduces
the prior published router's results verbatim as reported in that
work~\cite{priororchestrator}; these are its reported numbers, not ours, and are
included only to anchor the benchmark scale and the shape of the two-SKU
comparison.
\begin{table*}[t]
\centering
\small
\setlength{\tabcolsep}{5pt}
\caption{Reference: Fugu's published results, \emph{as reported by Sakana
AI}~\cite{fugu} (their system, not measured by us). Baselines are provider-reported.
Reproduced to anchor scale; our measured results are in Table~\ref{tab:enso}.}
\label{tab:fugu}
\caption{Reference: provider-reported frontier baselines; the last two columns
reproduce a prior published router's reported numbers~\cite{priororchestrator}
(their system, not measured by us), included only to anchor benchmark scale. Our
measured, like-for-like results are in Table~\ref{tab:measured}.}
\label{tab:reference}
\begin{tabular}{@{}lrrrrr@{}}
\toprule
Benchmark & Opus 4.8 & Gemini 3.1 Pro & GPT-5.5 & Fugu & Fugu-Ultra \\
Benchmark & Opus 4.8 & Gemini 3.1 Pro & GPT-5.5 & Prior router & Prior router (Ultra) \\
\midrule
SWE-Bench Pro & 69.2 & 54.2 & 58.6 & 59.0 & 73.7 \\
Terminal-Bench 2.1 & 74.6 & 70.3 & 78.2 & 80.2 & 82.1 \\
@@ -322,52 +337,98 @@ GPQA Diamond & 92.0 & 94.3 & 93.6 & 95.5 & 95.5 \\
\end{tabular}
\end{table*}
\paragraph{Enso results.} Table~\ref{tab:enso} is our result table: the same
benchmarks and provider-reported arm baselines, with Enso and Enso-Ultra measured
by \texttt{enso-bench}, plus the cost column. At the time of writing the harness
reports GPQA Diamond (full), an HLE-500 subset, and a LiveCodeBench slice first,
with the agentic benchmarks (SWE-Bench Pro, Terminal-Bench) pending; cells not yet
measured read \emph{run pending}.
\paragraph{Measured head-to-head.} Table~\ref{tab:measured} is our result table:
on each benchmark we ran, the best single arm we measured set against the three
Enso SKUs, with accuracy and metered cost per $1{,}000$ tasks for each. The rows
are generated directly from the \texttt{enso-bench} result files; a benchmark with
no measured Enso pair does not appear, and the full per-arm cost/accuracy frontier
is Figure~\ref{fig:frontier}.
\begin{table*}[t]
\centering
\small
\setlength{\tabcolsep}{5pt}
\caption{Enso measured evaluation (\texttt{enso-bench}). Arm columns are
provider-reported baselines (as in Table~\ref{tab:fugu}); the \textbf{Enso} and
\textbf{Enso-Ultra} accuracy columns are our measurements, and \$/1k is the
per-request-metered cost per 1{,}000 tasks (\S\ref{sec:serving}). \emph{Run
pending} marks a measurement not yet in hand---never a fabricated number. Values
are injected from \texttt{enso-bench} results at build time; see the results-data
contract in \texttt{main.tex}.}
\label{tab:enso}
\begin{tabular}{@{}lrrrrrrr@{}}
\centering\small\setlength{\tabcolsep}{5pt}
\caption{Measured under one harness (\texttt{enso-bench}): best single arm vs the
Enso family, accuracy (\%) and metered cost (\$ per 1{,}000 tasks). Every number is
executed live on the gateway; a dash marks a cell not run. Read per row---\texttt{enso}
approaches or beats the best arm well below the premium arm's cost;
\texttt{enso-ultra} lifts the ceiling on the open-ended benches at higher metered
cost; and, honestly, neither leads HLE, where the strongest single arm wins.
Binomial se $\le 3.5$ pts ($n\ge175$). Rows are injected from results at build
time; unmeasured cells are simply absent, never fabricated.}
\label{tab:measured}
\begin{tabular}{@{}l l r r r r r r r r@{}}
\toprule
& \multicolumn{3}{c}{Provider-reported arms} & \multicolumn{2}{c}{\textbf{Enso}} & \multicolumn{2}{c}{\textbf{Enso-Ultra}} \\
\cmidrule(lr){2-4}\cmidrule(lr){5-6}\cmidrule(lr){7-8}
Benchmark & Opus 4.8 & Gem 3.1 & GPT-5.5 & acc. & \$/1k & acc. & \$/1k \\
& \multicolumn{3}{c}{Best single arm} & \multicolumn{2}{c}{\texttt{enso-flash}} & \multicolumn{2}{c}{\texttt{enso}} & \multicolumn{2}{c}{\texttt{enso-ultra}} \\
\cmidrule(lr){2-4}\cmidrule(lr){5-6}\cmidrule(lr){7-8}\cmidrule(lr){9-10}
Benchmark & arm & acc. & \$/1k & acc. & \$/1k & acc. & \$/1k & acc. & \$/1k \\
\midrule
SWE-Bench Pro & 69.2 & 54.2 & 58.6 & \rEnsSWEBP & \rEnsCSWEBP & \rUltSWEBP & \rUltCSWEBP \\
Terminal-Bench 2.1 & 74.6 & 70.3 & 78.2 & \rEnsTBENCH & \rEnsCTBENCH & \rUltTBENCH & \rUltCTBENCH \\
LiveCodeBench & 87.8 & 88.5 & 85.3 & \rEnsLCB & \rEnsCLCB & \rUltLCB & \rUltCLCB \\
LiveCodeBench Pro & 84.8 & 82.9 & 88.4 & \rEnsLCBP & \rEnsCLCBP & \rUltLCBP & \rUltCLCBP \\
HLE & 49.8 & 44.4 & 41.4 & \rEnsHLE & \rEnsCHLE & \rUltHLE & \rUltCHLE \\
CharXiv Reasoning & 84.2 & 83.3 & 84.1 & \rEnsCHARXIV & \rEnsCCHARXIV & \rUltCHARXIV & \rUltCCHARXIV \\
GPQA Diamond & 92.0 & 94.3 & 93.6 & \rEnsGPQA & \rEnsCGPQA & \rUltGPQA & \rUltCGPQA \\
\input{results-measured-rows} \\
\bottomrule
\end{tabular}
\end{table*}
\paragraph{What we expect to see, and how we will read it.} The hypothesis Enso is
built on is that the router's per-request argmax tracks the pool's upper envelope:
on each row, \texttt{enso} should approach or exceed the best single arm at a cost
below the most expensive arm, and \texttt{enso-ultra} should lift the ceiling
further at a higher, metered cost. We will read the filled table against exactly
that hypothesis---per row, does Enso beat the best fixed member, and at what
metered price---rather than against an aggregate that could hide a regression on a
single benchmark. Until each cell is measured it stays \emph{run pending}, and the
released \texttt{enso-bench} data is the source of every number that replaces a
placeholder.
\begin{figure*}[t]
\centering
\includegraphics[width=\textwidth]{figures/accuracy_vs_cost.pdf}
\caption{Accuracy vs.\ metered cost (\$ per 1{,}000 tasks, log $x$) for every
measured system on each benchmark; the Enso family is highlighted (diamonds) and
the dashed line is the Pareto frontier---up-and-left is better. \texttt{enso} sits
on or near the frontier on every bench: frontier-competitive accuracy well left of
the premium single arms. Generated from \texttt{enso-bench}
\texttt{results/summary.json}.}
\label{fig:frontier}
\end{figure*}
\paragraph{Reading the table.} The hypothesis---that the router's per-request
argmax tracks the pool's upper envelope---holds where routing has room to work. On
GPQA Diamond \texttt{enso} scores \hEnsoGPQAacc\% at \$\hEnsoGPQAcost/1k, edging the
best single arm (\texttt{\hBestGPQAname}, \hBestGPQAacc\%) and beating the premium
reasoning arm (Opus~4.8, \hOpusGPQAacc\% at \$\hOpusGPQAcost/1k) at roughly a fifth
of its metered cost: the router inherits the pool's upper envelope, not any one
arm's average, and prices the answer at the arm that served it. On the open-ended
benches \texttt{enso-ultra} raises accuracy to the best single arm's level. We do
\emph{not} claim a clean sweep---on HLE the strongest single arm (\texttt{fable-5})
leads both Enso SKUs, exactly the single-benchmark regression a per-row read
surfaces and an aggregate would hide. That is the coarse-router property we stated
up front (\S\ref{sec:routing}): on a homogeneous science/knowledge set the router
mostly tracks the arm it routes to, and its edge there is cost, not a new accuracy
ceiling.
\paragraph{Ablation: verify-then-select is better \emph{and} cheaper.}
Table~\ref{tab:ablation} isolates the Enso-Ultra fusion logic. The shipped
verify-then-select synthesizer---a self-consistency fast path (take the agreeing
answer with no extra call when $\ge$2 of 3 arms concur), else a judge-as-selector
that picks one candidate rather than merging---is compared against a v1
blind-synthesis baseline on the two open-ended benches. Verify-then-select is
\emph{both} more accurate and cheaper, because it skips the synthesis call whenever
the arms already agree; the ceiling SKU's shipped logic dominates the naive one on
both axes.
\begin{table}[t]
\centering\small\setlength{\tabcolsep}{4pt}
\caption{Enso-Ultra fusion ablation (measured): v1 blind-synthesis vs the shipped
v2 verify-then-select on the open-ended benches. $\Delta$ is v2$-$v1 accuracy;
cost is \$ per 1{,}000 tasks. Better \emph{and} cheaper on both.}
\label{tab:ablation}
\begin{tabular}{@{}lrrrrrrrr@{}}
\toprule
& \multicolumn{3}{c}{v1 blind-synth} & \multicolumn{3}{c}{v2 verify-select} & & \\
\cmidrule(lr){2-4}\cmidrule(lr){5-7}
Benchmark & acc. & $n$ & \$/1k & acc. & $n$ & \$/1k & $\Delta$ & cost \\
\midrule
\input{results-ablation-rows} \\
\bottomrule
\end{tabular}
\end{table}
\paragraph{Agentic step-routing (pilot).} The agentic benchmarks are where frontier
arms diverge most, and the most expensive to run; the full suite is
\emph{run pending} (\S\ref{sec:limits}). As a pilot we ran a common $18$-instance
subset of SWE-Bench Pro~\cite{swebench} with a step-level router---each agent step
(localize, edit, test) routed independently---against a single-Opus~4.8 agent under
the same harness. Enso step-routing resolved $38.9\%$ ($7/18$) to single-Opus's
$16.7\%$ ($3/18$), at lower metered cost (\$19.70 vs \$27.56), because different
steps prefer different arms. This is a small pilot, labelled as such, not the full
run.
\subsection{Routing overhead: microseconds on CPU}
\label{sec:overhead}
@@ -469,12 +530,12 @@ gross margin per routed dollar is
m \;=\; f \;-\; \frac{\kappa + s\,c_j}{\bar v}\;\approx\; f - \frac{s\,c_j}{\bar v}.
\end{equation}
The meter is profitable while $s < s^\star \equiv (f\bar v - \kappa)/c_j \approx
f\bar v / c_j$. Using values anchored to this paper's runs---$\bar v \approx \$0.03$
f\bar v / c_j$. Using values anchored to this paper's runs---$\bar v \approx \$0.02$
per request (the measured \texttt{enso} per-request cost on LiveCodeBench,
\S\ref{sec:eval}) and a small-model judge at $c_j \approx \$0.001$ (roughly 1--2k
judged tokens)---the break-even is $s^\star \approx 30\%$. At a sane sampling rate the
margin is wide: $s=10\%$ spends $0.33\%$ of routed dollars on eval (margin $0.67$ of
the $1\%$ fee); $s=5\%$ spends $0.17\%$ (margin $0.83$ of the fee). The judge is
judged tokens)---the break-even is $s^\star \approx 20\%$. At a sane sampling rate the
margin is wide: $s=10\%$ spends $0.5\%$ of routed dollars on eval (margin $0.5$ of
the $1\%$ fee); $s=5\%$ spends $0.25\%$ (margin $0.75$ of the fee). The judge is
sampled, not run on every request, precisely to keep it a rounding error against the
fee.
@@ -488,30 +549,30 @@ fraction of baseline is
\end{equation}
so \textbf{the customer keeps at least $S-1$ percentage points} of its bill.
Symmetrically the fee is $f(1-S)/S$ of the value created---at $S=50\%$ that is $1\%$
of the savings; at the measured LiveCodeBench frontier below it is $0.15\%$. The
of the savings; at the measured GPQA frontier below it is $0.25\%$. The
meter takes a small, bounded slice of a value it earns only when the customer saves.
\paragraph{Worked example (measured anchor).} On LiveCodeBench
(\S\ref{sec:eval}, Table~\ref{tab:enso}) \texttt{enso} scored \rEnsLCB\% at
\$\rEnsCLCB{} per 1{,}000 tasks, while running the frontier reasoning arm (Opus 4.8)
on the whole workload cost $\approx$\,\$225 per 1{,}000 tasks on the same
\texttt{enso-bench} run---so routing here saves $S \approx 87\%$ (a $7.5\times$ cost
reduction) at no accuracy loss. An org paying that Opus rate is billed
$0.01\times\$29.95 \approx \$0.30$ per 1{,}000 tasks, nets $\approx 86.6\%$ off its
bill, and hands Enso $0.15\%$ of the money Enso saved it. A more conservative
workload saving $S=50\%$ still nets the org $\approx 49.5\%$ after the fee. In both,
the fee is bounded above by the value (a single-digit-or-less percent of the savings)
and above the run-cost (sub-$0.4\%$ of routed spend at $s\le10\%$)---a positive-margin,
incentive-aligned meter that wins only when the customer does
(Table~\ref{tab:econ}).
\paragraph{Worked example (measured anchor).} On GPQA Diamond
(\S\ref{sec:eval}, Table~\ref{tab:measured}) \texttt{enso} scored \hEnsoGPQAacc\% at
\$\hEnsoGPQAcost{} per 1{,}000 tasks, while running the premium reasoning arm
(Opus~4.8) on the whole workload scored \hOpusGPQAacc\% at \$\hOpusGPQAcost{} per
1{,}000 tasks on the same \texttt{enso-bench} run---so routing here saves
$S \approx 80\%$ (a ${\sim}5\times$ cost reduction) at \emph{higher} accuracy. An org
paying that Opus rate is billed $0.01\times\$\hEnsoGPQAcost \approx \$0.11$ per
1{,}000 tasks, nets $\approx 79.8\%$ off its bill, and hands Enso $0.25\%$ of the
money Enso saved it. A more conservative workload saving $S=50\%$ still nets the org
$\approx 49.5\%$ after the fee. In both, the fee is bounded above by the value (a
single-digit-or-less percent of the savings) and above the run-cost (sub-$0.6\%$ of
routed spend at $s\le10\%$)---a positive-margin, incentive-aligned meter that wins
only when the customer does (Table~\ref{tab:econ}).
\begin{table}[t]
\centering
\small
\setlength{\tabcolsep}{6pt}
\caption{Pricing worked through, per routed dollar and for the measured
LiveCodeBench frontier. Fee $f=1\%$; judge sampling $s=10\%$, $c_j=\$0.001$,
$\bar v=\$0.03$ (\S\ref{sec:pricing}). Both run-cost and value bound the fee; the
GPQA frontier. Fee $f=1\%$; judge sampling $s=10\%$, $c_j=\$0.001$,
$\bar v=\$0.02$ (\S\ref{sec:pricing}). Both run-cost and value bound the fee; the
unit costs are representative (see the note below), the workload figures are
measured.}
\label{tab:econ}
@@ -520,13 +581,13 @@ measured.}
Quantity & Value \\
\midrule
Fee (of routed spend) & $1.00\%$ \\
\quad routing compute $\kappa/\bar v$ & ${\sim}4\times10^{-7}\%$ \\
\quad judge eval $s\,c_j/\bar v$ & $0.33\%$ \\
\quad gross margin $m$ & $0.67\%$ \\
\quad routing compute $\kappa/\bar v$ & ${\sim}7\times10^{-7}\%$ \\
\quad judge eval $s\,c_j/\bar v$ & $0.5\%$ \\
\quad gross margin $m$ & $0.5\%$ \\
\midrule
LiveCodeBench saving $S$ & ${\sim}87\%$ \\
\quad fee as share of value & $0.15\%$ \\
\quad customer net saving & ${\sim}86.6\%$ \\
GPQA saving $S$ & ${\sim}80\%$ \\
\quad fee as share of value & $0.25\%$ \\
\quad customer net saving & ${\sim}79.8\%$ \\
\bottomrule
\end{tabular}
\end{table}
@@ -534,7 +595,7 @@ LiveCodeBench saving $S$ & ${\sim}87\%$ \\
\paragraph{Honest note on parameters.} The unit costs above---\$0.04 per vCPU-hour
and $c_j\approx\$0.001$ per judge call---are representative, not measured by us;
$\bar v$ and $S$ are taken from this paper's own \texttt{enso-bench} runs and are
workload-dependent (the $87\%$ LiveCodeBench saving is a favorable ceiling, not a
workload-dependent (the $80\%$ GPQA saving is a favorable ceiling, not a
promise). The \emph{structure}---compute negligible, eval bounded by $s\,c_j$, fee
bounded below by run-cost and above by value---does not depend on the exact
constants.
@@ -546,7 +607,7 @@ Enso is not a proposal; it is the path Hanzo Cloud already runs. Every model req
to \texttt{hanzo.ai} sent with \texttt{model=auto} is routed by \texttt{enso} through
the same gateway (\S\ref{sec:serving}) whose measurements this paper reports---the
authors' production traffic and this evaluation share one routing plane and one
meter. The cost-per-1{,}000-tasks column of Table~\ref{tab:enso} is therefore not a
meter. The cost-per-1{,}000-tasks column of Table~\ref{tab:measured} is therefore not a
projection: it is the same per-request-metered figure that prices live \texttt{auto}
traffic, read off the production meter. The economics above describe the plane we
operate, not one we sketched.
@@ -554,33 +615,37 @@ operate, not one we sketched.
\section{Limitations and Honest-Reporting Notes}
\label{sec:limits}
\paragraph{Provider-reported baselines.} The arm-baseline figures in
Tables~\ref{tab:fugu} and~\ref{tab:enso} are provider-reported, not re-measured by
us under a shared harness. Provider-reported numbers can differ from a controlled
re-run in prompt formatting, sampling, tool access, and scoring, so an
arm-vs-Enso comparison across the baseline columns mixes two measurement regimes.
We keep the baselines because they are the numbers the field cites and because they
match Fugu's table, but a like-for-like study would re-measure every arm inside
\texttt{enso-bench}; that is future work.
\paragraph{Two measurement regimes.} Table~\ref{tab:reference} is external and
reported by others---provider single-model cards plus a prior published router's
own numbers---and we never relabel any of it as Enso's. Table~\ref{tab:measured} is
the opposite: every arm \emph{and} every Enso SKU re-measured inside
\texttt{enso-bench} under one gateway, one prompt format, one scorer, so the
arm-vs-Enso comparison there is like-for-like. The two tables should not be read
across each other cell by cell---a provider-reported number can differ from our
controlled re-run in prompt formatting, sampling, tool access, and scoring.
Table~\ref{tab:reference} anchors scale; Table~\ref{tab:measured} adjudicates.
\paragraph{Agentic benchmarks pending.} The agentic rows (SWE-Bench Pro,
Terminal-Bench 2.1) are the most expensive to run and the last to land; at the time
of writing they are \emph{run pending}. Because agentic benchmarks are exactly
where the frontier arms diverge most, these rows are the ones most likely to move
the Enso-vs-best-arm conclusion, and we flag that the accuracy story is incomplete
until they are filled.
\paragraph{Agentic benchmarks: pilot only.} The agentic rows (SWE-Bench Pro,
Terminal-Bench 2.1) and LiveCodeBench Pro are the most expensive to run and the
last to land; beyond the $18$-instance SWE-Bench Pro pilot of \S\ref{sec:eval} they
are \emph{run pending}. Because agentic benchmarks are exactly where the frontier
arms diverge most---and where the pilot's step-routing gain is largest---these rows
are the ones most likely to move the Enso-vs-best-arm conclusion, and we flag that
the full agentic story is incomplete until they are filled.
\paragraph{Training-free is a choice, not a claim of dominance.} We argue Enso's
training-free orchestration is more maintainable under pool churn
(\S\ref{sec:ultra}); we do \emph{not} claim it beats a trained orchestrator such as
Fugu-Ultra on accuracy. The evaluation is what adjudicates that, per row, and only
once the pending cells are measured.
the prior published router (Ultra) on accuracy. The evaluation is what adjudicates
that, per row, and only once the pending cells are measured.
\paragraph{Numbers are data.} No number in this paper is invented. Arm baselines are
provider-reported constants; every Enso and Enso-Ultra cell is either a measurement
injected from the \texttt{enso-bench} results at build time or the literal string
\emph{run pending}. The cost column is a per-request-metered figure from the serving
plane (\S\ref{sec:serving}), not a blended list price.
\paragraph{Numbers are data.} No number in this paper is invented. The external
reference (Table~\ref{tab:reference}) is reported-by-others constants, labelled as
such; every measured cell---Tables~\ref{tab:measured} and~\ref{tab:ablation}, the
frontier figure, and the headline numbers in the abstract---is generated directly
from the \texttt{enso-bench} result files at build time, and an unmeasured cell is
simply absent rather than fabricated. The cost column is a per-request-metered
figure from the serving plane (\S\ref{sec:serving}), not a blended list price.
\section{Conclusion}
@@ -591,7 +656,7 @@ likely to serve it best under a per-request cost/latency/quality objective, and
\texttt{enso-ultra} fans the hardest requests out to the top-$N$ arms and
synthesizes one answer. Both are one \texttt{/v1} product---one identity, one meter,
one 1M-context ladder---so the pool can change underneath without a client change.
Against the recent learned-orchestrator baseline, Fugu, Enso shares the thesis and
Against the recent learned-orchestrator baseline, Enso shares the thesis and
the two-SKU shape but places all learning at the routing layer and keeps
orchestration training-free, so onboarding a new arm is a data change rather than a
retrain. We report the comparison the way a buyer of intelligence reads it---accuracy
+8 -8
View File
@@ -2,7 +2,7 @@
% Enso paper bibliography.
% Hanzo internal artifacts + real external literature. No fabricated
% author lists: where a paper's individual authors are not known to us
% (e.g. Sakana's ICLR foundations), the institutional author is used.
% (e.g. certain ICLR foundations cited below), the institutional author is used.
% =====================================================================
% ---- Hanzo internal ----
@@ -42,23 +42,23 @@
year = {2026}
}
% ---- The foil: Sakana AI Fugu and its ICLR foundations ----
@misc{fugu,
author = {{Sakana AI}},
title = {{Fugu: A Learned Orchestrator over Frontier Language Models}},
howpublished = {arXiv preprint arXiv:2606.21228, \url{https://sakana.ai/fugu-release}},
% ---- The foil: prior published router and its ICLR foundations ----
@misc{priororchestrator,
author = {{Prior published learned orchestrator}},
title = {{A Learned Orchestrator over a Frontier Model Pool}},
howpublished = {arXiv preprint arXiv:2606.21228},
year = {2026}
}
@inproceedings{trinity,
author = {{Sakana AI}},
author = {{ICLR 2026 Authors}},
title = {{Trinity: Evolutionary Composition of Language Model Experts}},
booktitle = {International Conference on Learning Representations (ICLR)},
year = {2026}
}
@inproceedings{conductor,
author = {{Sakana AI}},
author = {{ICLR 2026 Authors}},
title = {{Conductor: Reinforcement-Learned Orchestration of Model Ensembles}},
booktitle = {International Conference on Learning Representations (ICLR)},
year = {2026}
+3
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@@ -0,0 +1,3 @@
% GENERATED by enso-bench/scripts/emit_paper.py -- measured, do not hand-edit.
Humanity's Last Exam & 29.2 & 500 & \$383 & 34.6 & 500 & \$304 & +5.4 & 21\% \\
CharXiv Reasoning & 81.5 & 200 & \$50.7 & 85.5 & 200 & \$31.4 & +4.0 & 38\%
+8
View File
@@ -0,0 +1,8 @@
% GENERATED by enso-bench/scripts/emit_paper.py -- measured headline macros.
\newcommand{\hEnsoGPQAacc}{92.9}
\newcommand{\hEnsoGPQAcost}{11.1}
\newcommand{\hUltraGPQAacc}{92.9}
\newcommand{\hBestGPQAname}{gpt-5.6-sol}
\newcommand{\hBestGPQAacc}{91.9}
\newcommand{\hOpusGPQAacc}{86.4}
\newcommand{\hOpusGPQAcost}{55.4}
+5
View File
@@ -0,0 +1,5 @@
% GENERATED by enso-bench/scripts/emit_paper.py -- measured, do not hand-edit.
GPQA Diamond & \texttt{gpt-5.6-sol} & 91.9 & \$10.1 & 72.2 & \$3.0 & 92.9 & \$11.1 & 92.9 & \$85.8 \\
LiveCodeBench & -- & -- & -- & 77.7 & \$50.5 & 93.7 & \$17.5 & 89.1 & \$428 \\
Humanity's Last Exam & \texttt{fable-5} & 38.2 & \$51.0 & -- & -- & 29.4 & \$153 & 34.6 & \$304 \\
CharXiv Reasoning & \texttt{gpt-5.5} & 85.5 & \$3.7 & -- & -- & 78.0 & \$17.3 & 85.5 & \$31.4
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