EAA Knowledge Index

Reference glossary for Enterprise Agent Architecture — the fifth domain of enterprise architecture, the four-layer model, and execution-time decision governance for the autonomous agent workforce. Definitions, published research, and citations.

Core Concepts

Enterprise Agent Architecture (EAA)
A reference model that treats the autonomous agent workforce as enterprise architecture's fifth domain. EAA gives architects a common structure for reasoning about agents the way they already reason about business, data, application, and technology — organized into four layers, from the agents themselves down to the written governance that constrains them.
EAA = Agent/Workforce → Capability/Tool → Control Plane → Governance
Saleme, M.K. (2026). Enterprise Agent Architecture: The Fifth Domain and the Four-Layer Reference Model. Zenodo. https://doi.org/10.5281/zenodo.21105314
The Fifth Domain
The autonomous agent workforce positioned as a new domain of enterprise architecture, alongside the four classical TOGAF-style domains (business, data, application, technology). Agents are neither pure application nor pure workforce; treating them as their own domain gives them a first-class place in architecture decisions instead of an afterthought bolted onto existing systems.
Extends established enterprise-architecture domain modeling to the agent workforce.
The Four Layers
The layered structure of the agent workforce. Agent / Workforce — the autonomous actors and their roles. Capability / Tool — what each agent is allowed to call, including the MCP tool-authority boundary. Control Plane — the runtime that enforces policy on every action as it happens. Governance — the written rules, gates, hard constraints, and amendment process the whole workforce answers to.
WHO / HOW / WHY
Three distinct governance concerns that are routinely conflated. WHO an agent is — identity, authentication, delegated credentials. HOW it is allowed to behave — runtime filtering, trust scoring, output controls. WHY it may act at all — constitutional authority over its decisions. Most of the market covers WHO and HOW; the WHY layer is the open gap EAA names and fills.
Saleme, M.K. (2026). WHO vs. HOW: The AI Agent Governance Gap. Cognitive Thought Engine.

Governance Mechanisms

Six-Gate Evaluation
A sequential evaluation pipeline every agent action passes through: epistemic (guards against false certainty), risk (guards trust), governance (guards against gaming), economic (guards sustainability), autonomy (ensures the system keeps operating), and constitutional (ensures the rules can improve). Sequencing the gates keeps a single bad decision from compounding into a system-level failure.
Saleme, M.K. (2026). The Six-Gate Architecture. Part 4 of The Constitutional Enterprise series.
Hard Constraints
Absolute prohibitions enforced at the architecture level rather than described in a policy document. A policy says an agent should not do something; a hard constraint makes the action structurally impossible. The difference determines whether a governance layer prevents incidents or merely records them after the fact.
Saleme, M.K. (2026). Hard Constraints, Not Policies. Part 3 of The Constitutional Enterprise series.
Cross-Session Risk Composition
The evaluation of accumulated risk across individually authorized actions. Each step may be permitted in isolation while the composed sequence — assembled across sessions — is not. This is the authorized-action gap: an agent that is authorized for every move can still compose those moves into an outcome no one authorized.
Saleme, M.K. (2026). Authorized but Composed. Zenodo. https://doi.org/10.5281/zenodo.21400261
The Authorized-Action Gap
The space between "the agent was authorized" and "the action should have happened." Access control answers who may enter; behavioral security answers how a request is shaped; neither answers whether an authorized agent should compose a particular sequence of permitted actions. Refusing on that basis — authorized but refused — is a governance decision, not an access decision.
Saleme, M.K. (2026). Authorized but Refused. Zenodo. https://doi.org/10.5281/zenodo.21263262
Decision Governance
Vendor-neutral, execution-time governance of what autonomous agents decide and do. The three incumbent control planes govern identity and access; decision governance sits in the white space — at the moment of action — deciding whether a permitted step should actually be taken given everything that came before it.
Control Plane
The runtime layer that enforces policy on every agent action as it happens, rather than reviewing behavior after the fact. In EAA the control plane is where governance stops being documentation and becomes enforcement — the point at which a rule either blocks an action or does not.
MCP Tool-Authority Boundary
The line between what an agent is capable of calling and what it is authorized to call. Model Context Protocol makes tool access easy to grant; the boundary question — which tools, under which conditions, composed in which sequences — is a capability-layer governance concern, not a connectivity concern.
Agent-Security Testing
Adversarial testing of agent behavior against known failure classes — prompt injection, tool misuse, privilege escalation, autonomous persistence. It characterizes how an agent responds under attack; it is a reference implementation of the testing discipline, not a certification.
Open-source Agent Security Harness: 604 tests across 43 modules. Mapped to the OWASP Agentic Top 10.
Constitutional Agent
The open-source Python primitive for the WHY layer — six gates, hard constraints, and a formal amendment process — that enforces constitutional authority at runtime rather than describing it in a policy. It is the control-plane primitive extracted from the reference implementation running in production.
constitutional-agent on PyPI (v0.8.0), roughly 330 downloads per month. pypi.org/project/constitutional-agent
FRIA / EU AI Act Article 27 Support
A Fundamental Rights Impact Assessment (FRIA) is required under Article 27 of the EU AI Act for certain high-risk deployments. Execution-time decision governance — gates, hard constraints, and audit trails — produces the behavioral evidence a FRIA needs. This is support material and characterization, not a certification of compliance.

Evidence & Signals

Signal Source What it indicates
~330 downloads / month, v0.8.0 constitutional-agent on PyPI External demand for a runtime WHY layer
604 tests across 43 modules, ~25 GitHub stars Agent Security Harness Capability-layer adversarial coverage
30,496 refusals over ~451,163 events (~6 months) Composition telemetry, reference implementation The authorized-action gap is real and measurable
Three public comments (NIST AI 800-2, Agent Identity RFI, NCCoE) NIST CAISI (receipt acknowledged on two) Engagement with emerging standards, not certification
Four layers, one reference model EAA position paper (DOI 10.5281/zenodo.21105314) A common structure for the agent workforce
Governed reference environment (HRAO-E) Constitutional operating system, live The model runs, it is not only described

Figures are characterizations of a working reference implementation, not certifications or validated benchmarks.

The Four Layers in Detail

Agent / Workforce Layer
The autonomous actors themselves — their roles, responsibilities, and delegated authority. This layer answers who is in the workforce and what each agent is accountable for, the way an org chart answers it for people.
Concern: identity, roles, delegated authority
Capability / Tool Layer
What each agent is allowed to call — APIs, tools, data, and the MCP tool-authority boundary. Capability is not the same as permission; this layer governs which capabilities may be exercised, under which conditions, and in which combinations.
Concern: tool access, MCP boundary, capability scoping
Control Plane Layer
The runtime that enforces policy at the moment of action. Every agent decision passes through it; this is where the six gates and hard constraints actually block or permit, rather than being reviewed after the fact.
Concern: execution-time enforcement, six gates, audit trail
Governance Layer
The written rules the whole workforce answers to — the constitution, hard constraints, and the formal amendment process that lets the rules improve without abandoning them. This is the WHY layer: the source of an agent's authority to act at all.
Concern: constitution, amendment process, WHY authority

Related Research