Route Anything: A Study of Model and Policy Routing for General-Purpose AI Systems
Authors: Pengfei Zhou, Yixing Ma, Hexin Wang, Weidong Tang, Zhenglin Wan, Wangbo Zhao, Yang You
Organizations: National University of Singapore, HPC-AI Lab · InfRec, Cardinal AI Lab · University of California, Berkeley · Hong Kong University of Science and Technology
Artificial general intelligence (AGI) requires a method that can understand, generate, reason, and act across diverse domains and modalities. Rather than relying on a single model to master every capability, a promising path toward AGI now is to orchestrate a heterogeneous ecosystem of specialized models, tools, and policies (candidates) into a unified AI system. At the heart of this vision lies a fundamental question: how can an AI system dynamically select and coordinate the most capable candidate for each task while balancing performance and computational cost? In this work, we present Route Anything, a unified framework for studying model and policy routing across general-purpose AI systems. We develop a unified theoretical foundation that characterizes optimal routing under quality--cost trade-offs and establishes how the information available to a router determines its attainable performance. To systematically investigate routing across diverse capabilities, we first construct an omni-modal trajectory matrix spanning 25 benchmarks across language understanding, image, video, and speech generation, coding and workplace agents, and robotic manipulation, comprising 374,401 scored runs from 452 candidate configurations. Building on this framework, we train and test different routers to investigate the potential of omni-modal model routing, the capabilities of learned routers, and the conditions under which routing improves efficiency. Our results reveal substantial opportunities for capability orchestration: per-input oracle routing outperforms the best fixed candidate by 5.4 points, and learned routers outperform it by 0.3 points across 16 benchmarks, by 2.1 points on video generation, and by 1.1 points on robot manipulation while using 24% less policy time. More importantly, routing raises efficiency by 8.82x on average compared with the reference model.
Figures & tables
Figure 1
Group
Benchmarks
Candidates
Inputs
Fixed
Best fixed in hindsight
Oracle
Gap
Text QA
7
3–4
9,482
83.27
83.27
87.56
4.28
Image-text QA
3
3
5,708
85.32
85.32
88.02
2.70
Image generation
5
4–6
1,515
82.93
82.99
87.92
4.99
Video generation
1
3
158
62.43
62.43
81.36
18.93
Speech generation
2
3
608
98.62
98.63
99.30
0.68
Code and workplace agents
5
4
343
69.17
69.78
77.29
8.11
Table 1: Per-input potential gain on the test split. Inputs on which every candidate of the pool is scored; values are benchmark metrics on a 0–100 scale, pooled over inputs. Fixed plays the best candidate per benchmark on training inputs, best fixed in hindsight the best candidate per benchmark on these test inputs, and the oracle the best candidate per input.
Figure 3
Study
Policies compared
Benchmarks
Inputs
Seeds
Fixed
Oracle
Potential gain (§ 3 )
fixed candidate, hindsight lookups
24
19,814
–
82.60
87.98
Rule-based tree (§ 3 , § 4.1 )
rule-based type router
18
5,034
–
77.03
87.44
One router (§ 4.1 )
capability-tree and untrained routers
16
3,444
1
79.68
84.80
Robots (§ 4.2 , § 4.3 )
outcome and winner-label routers
1
2,000
1
70.45
88.85
Targets (§ 4.3 , § 4.4 )
outcome and type routers
11
1,302
4
68.30
75.84
Winner labels (§ 4.3 )
12 winner-label recipes
16
3,211
1
79.44
85.77
Table 2: Evaluation panels. Each study uses the test inputs on which all its compared policies are scored; fixed-candidate and oracle scores (0–100) are comparable only within a row. The image-routing suite of Section 4.1 uses 158 GenEval2 and 193 Qwen-Image-Bench prompts, and the image price routes of Section 5.1 use the 1,515 image-generation inputs of Table 1 .
Group (benchmarks)
Inputs
Fixed
Router
Oracle
Router − fixed
Share
Text QA (3)
588
65.14
64.97
71.43
−0.17
−3%
Code and workplace agents (5)
519
69.24
70.01
74.78
+0.77
14%
Image generation (5)
1,559
82.96
83.21
87.92
+0.25
5%
Video generation (1)
161
62.17
64.28
80.22
+2.12
12%
Speech generation (2)
617
98.63
98.63
99.30
0.00
0%
All 16 benchmarks
3,444
79.68
79.98
84.80
+0.30
6%
Table 3: Learned routers against the fixed candidate and the oracle. Test inputs; one training seed. Share is the router’s gain over the fixed candidate divided by the oracle’s. The first block is the capability-tree router; the robot row is the outcome router of Section 4.2 .
Figure 6Figure 7
Study
Policy
Inputs
Score
− matched fixed [95% CI]
11 benchmarks, 4 seeds
Matched fixed candidate
1,302
68.30
–
Outcome router
1,302
67.90
−0.40[−1.19,+0.33]
68-type classifier + table
1,302
66.98
−1.32[−3.05,+0.34]
Oracle
1,302
75.84
+7.55
16 benchmarks
Fixed candidate (best training mean)
3,211
79.44
–
Winner-label router (generative)
3,211
78.87
−0.58
Table 4: Training targets and the fixed baseline. Paired 95% intervals over source groups (scenes for robots). The first block averages four training seeds on 1,302 test inputs of 11 text, agent, and image benchmarks; the fixed candidate is matched (Section 4.4 ).
Figure 9
Testbed (resource)
Reference
Route
ΔV [95% CI]
η/ηB
Code, CodeRouterBench ($)
Always Opus 4.6
Fitted, ϵ=0
−0.44[−1.75,+0.97]
25.5×
Certified, ϵ=0
≥0 in 200 of 200
19.4×
Text QA, RouterBench ($)
Always GPT-4
Fitted, ϵ=0
−0.40[−0.84,+0.08]
7.1×
Certified, ϵ=0
≥0 in 200 of 200
6.7×
Image generation ($)
Fixed generator
Fitted, ϵ=0.5
−0.47[−0.87,−0.06]
1.35×
Fitted, ϵ=2
−1.56[−2.39,−0.73]
2.03×
Table 5: Price routes across testbeds. Test-set quality change ΔV=E[V−YB] in points (0–100) with paired 95% intervals, and efficiency η/ηB against the reference. Fitted routes meet the floor on fitting data; certified routes are medians over 200 random halvings of the fitting data (Proposition 5 ).
Figure 11
Appendix figures & tables8 assets
Supplementary material from the paper’s appendix.
Appendix
Benchmark
Inputs
Fixed candidate
Fixed
Best fixed in hindsight
Oracle
Gap
Text QA
MMLU-Pro
2,403
Opus 5.5
92.55
92.55
95.21
2.66
MMLU-Redux
1,080
Opus 5.5
96.67
96.67
98.06
1.39
SuperGPQA
5,300
Opus 5.5
78.26
78.26
83.66
5.40
GPQA (extended)
106
Opus 5.5
90.57
90.57
92.45
1.89
AA-LCR
42
Opus 5.5
97.62
97.62
100.00
2.38
Appendix
Table 6: Per-benchmark potential gain on the test split (Table 1 ). The best fixed candidate in hindsight is named when it differs from the fixed candidate chosen on training inputs.
Benchmark
Inputs
Fixed candidate
Fixed
Router
Oracle
AA-LCR
42
Opus 5.5
97.62
95.24
100.00
AA-Omniscience
120
Opus 5.5
77.50
77.50
85.83
HLE (text)
426
Opus 5.5
58.45
58.45
64.55
SciCode
187
Opus 5.5
70.05
70.05
70.59
Terminal-Bench
36
Opus 5.5
69.44
77.78
86.11
AutomationBench
160
Opus 5.5
92.75
92.75
96.53
Appendix
Table 7: Per-benchmark results of the capability-tree router (first block of Table 3 ); one training seed. SciCode steps are aligned across models; 175 of its 187 inputs have one scored candidate.
Benchmark
Inputs
Fixed candidate
Fixed
Outcome router
Type router
Oracle
AA-LCR
42
Opus 5.5
97.62
95.24
97.62
100.00
AA-Omniscience
120
Opus 5.5
77.50
77.29
71.88
85.83
HLE (text)
431
Opus 5.5
58.24
57.95
56.61
64.27
AA-Briefcase
1
GPT-6.1 Sol
75.00
62.50
50.00
75.00
AutomationBench
160
Opus 5.5
92.75
92.70
92.54
96.53
GDP.pdf
100
GPT-6.1 Sol
21.00
20.50
20.00
36.00
Appendix
Table 8: Per-benchmark results of the 11-benchmark study (first block of Table 4 ), averaged over four training seeds; the fixed candidate is matched.
Fixed generator
Half-point route
Benchmark
Test prompts
Candidate
Quality
m$
Candidate
Quality
m$
GenEval2
160
GPT Image 2.5
82.48
208.8
GPT Image 2.5
82.48
208.8
Qwen-Image-Bench
193
GPT Image 2.5
64.09
211.1
Grok Imagine 2.0
61.16
60.0
LongT2I
543
MAI-Image 2.6
86.14
39.4
MAI-Image 2.6
86.14
39.4
OneIG
427
FLUX 3
83.35
48.0
Qwen-Image 3
83.02
40.0
WISE
192
Qwen-Image 3
92.19
40.0
Qwen-Image 3
92.19
40.0
Appendix
Table 9: Image price routes: test quality (0–100) and price (m$ per image) of the fixed generator and of the half-point route of Table 5 , fitted on training prompts.
Policy
η/ηB [CI]
Cost
ΔV [CI]
21 cells, unconstrained
28.187 [26.840, 29.659]
0.395
−0.0201 [ −0.0343 , −0.0056 ]
21 cells, ϵ=0
25.516 [24.278, 26.903]
0.452
−0.0044 [ −0.0175 , +0.0097 ]
21 cells, ϵ=0.01
27.612 [26.311, 29.072]
0.409
−0.0140 [ −0.0272 , −0.0004 ]
9 dimensions, unconstrained
28.024 [26.713, 29.452]
0.398
−0.0192 [ −0.0332 , −0.0047 ]
9 dimensions, ϵ=0
22.733 [21.584, 23.954]
0.502
−0.0090 [ −0.0227 , +0.0060 ]
Fixed Qwen3-Max dispatch
20.097 [18.965, 21.297]
0.525
−0.0416 [ −0.0549 , −0.0275 ]
Appendix
Table 10: CodeRouterBench policies on the 2,919 test tasks. Dollar efficiency η/ηB , cost in mpertask,and\Delta V=\mathbb{E}[V-Y_{B}],withpaired95\epsilon\geq 0.02theyareslackandgivetheunconstrainedpolicy.Fixeddispatchplaysthebestprobingmodel,whichisalsothecheapest(Qwen3−Max);theper−taskoracle,anin−sampleceiling,giveseachtaskthecandidatemaximizingV-\eta^{\star}C$ on its realized outcomes.
Dataset, threshold
Splits
Count
Paired
Residual
Indep.
Saving
Marginal
CodeRouterBench, θ=1
1
139
97.1%
86.3%
86.3%
95.7%
46.8%
CodeRouterBench, θ=0.5
1
194
96.4%
94.3%
91.8%
93.3%
40.7%
RouterBench, θ=0.5
10
5,539
63.9%
61.9%
35.9%
63.5%
14.6%
RouterBench, θ=1
10
212
64.6%
53.8%
36.3%
48.1%
0.0%
Appendix
Table 13: Best-candidate selection: the share of comparisons (one portfolio with several candidate additions) in which a rule’s fitted choice has the highest test efficiency. Counts sum over splits, which share tasks. Paired ranks Gm(S) of Eq. ( 8 ); residual ranks Nm(S) ; Indep. assumes independent failures; saving ranks rmb−dm .
Verifier
AUROC
r(θ=0.5) [95% CI]
r(θ=1) [95% CI]
Q(θ=0.5)
Compiler (static gate)
0.766
4.09 [3.23, 5.45]
4.09 [3.23, 5.45]
−0.024
Visible examples
0.537
1.98 [1.72, 2.35]
1.06 [1.03, 1.10]
−0.036
Hidden tests
0.994
2.87 [2.38, 3.53]
2.37 [2.03, 2.80]
+0.024
LLM judge
0.824
1.09 [1.00, 1.21]
0.64 [0.61, 0.66]
−0.012
Released-score oracle
1.000
2.46 [2.09, 2.93]
2.46 [2.09, 2.93]
+0.045
Appendix
Table 14: Verifier choice changes the cascade’s efficiency and quality. r=η/ηB ; Q is mean score change. Qwen3-Max primary; the judge is charged at the primary’s token price.
Signal source
Native [95% CI]
Threshold [95% CI]
Within dimension
Fine-tuned Qwen 27B
0.555 [0.490, 0.614]
0.555 [0.490, 0.614]
0.062
Fine-tuned Qwen 9B
0.546 [0.475, 0.608]
0.546 [0.475, 0.608]
0.078
Fine-tuned Qwen 2B
0.466 [0.397, 0.531]
0.417 [0.355, 0.479]
−0.006
Fine-tuned Qwen 0.8B
0.422 [0.348, 0.491]
0.082 [0.066, 0.098]
−0.008
Logistic regression
−1.218 [ −1.590 , −0.869 ]
0
−0.002
TF-IDF MLP
−1.736 [ −2.178 , −1.342 ]
0
−0.012
Appendix
Table 15: Cross-fitted capture of the nine released CodeRouterBench routers as signals Z (chose Qwen3-Max) for Qwen3-Max at θ=1 , with no signal charge. Native use attempts on Z=1 , threshold use when sZ>a/b ; the last column applies the threshold rule given the benchmark dimension and divides the aggregated saving by the aggregated bound.
Adaptive model routing selects models or specialized experts per input to balance prediction quality, computational cost, latency, and resource constraints.
Compound AI systems promise capabilities beyond those of individual models, yet their success depends critically on effective orchestration. Existing routing approaches face two limitations: (1) input-level routers make coarse query-level decisions that ignore evolving task requirements; (2) RL-trained orchestrators are expensive to adapt and often suffer from routing collapse, repeatedly invoking one strong but costly option in multi-turn scenarios. We introduce SkillOrchestra, a framework for skill-aware orchestration. Instead of directly learning a routing policy end-to-end, SkillOrchestra learns fine-grained skills from execution experience and models agent-specific competence and cost under those skills. At deployment, the orchestrator infers the skill demands of the current interaction and selects agents that best satisfy them under an explicit performance-cost trade-off. Extensive experiments across ten benchmarks demonstrate that SkillOrchestra outperforms SoTA RL-based orchestrators by up to 22.5% with 700x and 300x learning cost reduction compared to Router-R1 and ToolOrchestra, respectively. These results show that explicit skill modeling enables scalable, interpretable, and sample-efficient orchestration, offering a principled alternative to data-intensive RL-based approaches. The code is available at: https://github.com/jiayuww/SkillOrchestra.
Jiayu Wang, Yifei Ming, Zixuan Ke +3
University of Wisconsin-Madison · Salesforce AI Research
Agent performance depends on both the underlying model and the harness that manages its tool use and execution. Selecting a suitable pair requires accounting for their compatibility, yet training samples may cover only a subset of the growing combination space. We introduce HM-Router, a routing method that jointly selects a model and harness for each query. It learns separate model and harness representations shared across routes, with an interaction term inspired by canonical polyadic (CP) tensor decomposition to capture how their compatibility varies with the query. This sharing allows training samples from observed pairs to inform predictions for unobserved combinations. We curate a benchmark from 12 public agent benchmarks, covering 293 routes, 73 models, and 25 harnesses. HM-Router exceeds the strongest evaluated learned baseline by 7.3 percentage points in mean routing accuracy and leads at all seven evaluated cost budgets on the six-benchmark subset. When 90% of routes have their training outcomes withheld, allowing unobserved combinations improves normalized accuracy by 15.8 points over restricting the same router to observed routes. HM-Router has also demonstrated training sample efficiency for new routes and components and generalization to unseen benchmarks. Our code and data are open-sourced at https://github.com/hmarkc/HM-Router.
Hao Mark Chen, Royson Lee, Yasuyuki Okoshi +3
Imperial College London · Samsung · Institute of Science Tokyo
Is monolithic scaling the only path to AGI? This paper challenges the dogma that purely scaling a single model is sufficient to achieve Artificial General Intelligence. Instead, we identify Agentic AI as a necessary paradigm for mastering the complex, heterogeneous distribution of real-world tasks. Through rigorous theoretical derivations, we contrast the optimization constraints of monolithic learners against the efficiency of Agentic systems, progressing from simple routing mechanisms to general Directed Acyclic Graph (DAG) topologies. We demonstrate that Agentic AI achieves exponentially superior generalization and sample efficiency. Finally, we discuss the connection to Mixture-of-Experts, reinterpret the instability of current multi-agent frameworks, and call for greater research focus on Agentic AI.
Junwei Liao, Shuai Li, Muning Wen +2
1Shanghai Jiao Tong University 2Shanghai Innovation Institute · 1Shanghai Jiao Tong University · University College London.