Agent Primitives: Reusable Latent Building Blocks for Multi-Agent Systems

ICML 2026

Authors

Haibo Jin, Peng Kuang, Ye Yu, Xiaopeng Yuan, and Haohan Wang.

School of Information Sciences and Siebel School of Computing and Data Science, University of Illinois Urbana-Champaign.

Venue

Proceedings of the 43rd International Conference on Machine Learning (ICML 2026).

Agent Primitives poster preview

Poster preview for Agent Primitives.

Abstract

While existing multi-agent systems (MAS) can handle complex problems by enabling collaboration among multiple agents, they are often highly task-specific, relying on manually crafted agent roles and interaction prompts. This increases architectural complexity and limits reusability across tasks.

We propose Agent Primitives, a set of reusable latent building blocks for LLM-based MAS. Inspired by neural network design, where complex models are built from reusable components, we observe that many existing MAS architectures can be decomposed into a small number of recurring internal computation patterns. We instantiate three primitives: Review, Voting and Selection, and Planning and Execution. Each primitive communicates via key-value (KV) cache to mitigate information degradation across multi-stage interactions.

Motivation

LLM-based multi-agent systems have emerged as a promising approach for tackling complex real-world problems. However, many systems are designed as task-specific architectures, with specialized roles and interaction prompts built from scratch. As the task becomes more complex, the system design also becomes more complex.

Agent Primitives aim to make multi-agent computation reusable. Rather than designing every agent system as a new workflow, we extract recurring computation patterns and use them as modular latent building blocks.

Primitive types

  • Review Primitive — a Solver generates an initial answer, a Critic reviews it, and the Solver refines the answer.
  • Voting and Selection Primitive — multiple candidate agents produce alternatives, and a selection stage chooses or synthesizes the final answer.
  • Planning and Execution Primitive — a Planner decomposes a task, and an Executor carries out the planned steps.

Framework overview

The Organizer agent automatically selects and composes primitives for each query, guided by a lightweight knowledge pool of previously successful configurations. This forms a primitive-based MAS whose internal agents communicate through latent KV-cache states rather than only decoded text.

Overview of Agent Primitives framework

Overview of Agent Primitives and the Organizer-based composition process.

Results at a glance

+12.0–16.5% average accuracy improvement over single-agent baselines
~3× lower token usage and latency compared with text-based MAS
1.3×–2.6× overhead relative to single-agent inference

Experiments evaluate math problem solving, code generation, and question answering across Qwen3-8B, DeepSeek-R1-Distill-Qwen-32B, and DeepSeek-R1-Distill-Llama-70B. Primitive-based MAS improve average accuracy while reducing the cost of multi-agent communication compared with text-based MAS.

Models Methods AIME25 AIME24 MATH GSM8K HumanEval+ MBPP+ MedQA GPQA Avg.
Qwen3-8BSingle46.7%50.0%60.8%81.1%74.4%64.8%53.0%39.9%58.8%
TextMAS53.3%53.3%61.4%92.3%80.5%69.5%75.0%43.4%66.1% (+7.3 pp)
LatentMAS53.3%56.7%62.6%93.8%80.5%74.6%75.3%45.5%67.8% (+8.9 pp)
Review60.0%63.3%61.0%93.2%78.6%70.6%64.2%48.9%67.5% (+8.6 pp)
Voting66.7%70.0%61.4%91.8%81.0%74.3%70.3%55.0%71.3% (+12.5 pp)
Planning66.7%63.3%60.8%93.2%78.6%75.9%67.0%51.0%69.6% (+10.7 pp)
Primitives-based MAS73.3%76.7%63.7%94.2%82.3%75.9%76.7%59.6%75.3% (+16.5 pp)
DeepSeek-R1-Distill-Qwen-32BSingle53.3%73.3%63.4%93.8%80.5%73.8%68.0%62.1%71.0%
TextMAS53.3%73.3%68.0%93.8%82.3%74.6%79.6%62.6%73.4% (+2.4 pp)
LatentMAS56.7%73.3%78.2%95.2%83.5%75.7%81.2%63.6%75.9% (+4.9 pp)
Review53.3%70.0%71.3%94.6%81.1%73.8%73.0%62.1%72.4% (+1.4 pp)
Voting56.7%70.0%74.7%95.0%86.6%74.6%79.3%63.1%75.0% (+4.0 pp)
Planning53.3%66.7%74.6%93.8%85.3%74.3%75.0%62.6%73.2% (+2.2 pp)
Primitives-based MAS63.3%73.3%79.8%95.0%86.6%75.7%82.7%64.6%77.6% (+6.6 pp)
DeepSeek-R1-Distill-Llama-70BSingle50.0%70.0%69.6%92.4%82.3%66.4%64.5%65.2%70.1%
TextMAS53.3%70.0%72.8%93.2%82.3%68.8%77.8%65.7%73.0% (+2.9 pp)
LatentMAS40.0%43.3%78.6%78.6%73.2%55.6%68.6%41.9%60.0% (-10.1 pp)
Review50.0%70.0%75.9%91.8%82.3%67.2%72.9%65.2%71.9% (+1.9 pp)
Voting56.7%73.3%77.2%93.8%82.9%68.8%77.8%65.7%74.5% (+4.5 pp)
Planning50.0%63.3%75.6%92.4%82.3%66.7%74.0%65.2%71.2% (+1.1 pp)
Primitives-based MAS56.7%76.7%79.3%93.8%85.3%70.6%81.9%66.7%76.4% (+6.3 pp)

Accuracy (%) comparison on math problem solving, code generation, and Q&A tasks. Avg. reports average accuracy and improvement over the single-agent baseline in percentage points.

Paper

Agent Primitives: Reusable Latent Building Blocks for Multi-Agent SystemsPDF.

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BibTeX citation

@inproceedings{jin2026agentprimitives,
  title={Agent Primitives: Reusable Latent Building Blocks for Multi-Agent Systems},
  author={Jin, Haibo and Kuang, Peng and Yu, Ye and Yuan, Xiaopeng and Wang, Haohan},
  booktitle={Proceedings of the 43rd International Conference on Machine Learning},
  year={2026}
}