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Terminology

Canonical vocabulary for AI Notes. Prefer these terms in prose and code.

Core

TermMeaning
Model / LM / LLMNext-token (or multimodal) predictor used as a component
CompletionSingle model call → continuation
ChainFixed sequence of model/tool steps
WorkflowCode-owned control flow; model fills steps
AgentStateful decision system: loop over actions under a policy with state & environment
Autonomous systemAgent (or fleet) with broad action rights; not the default goal of this book
EnvironmentExternal world + tools + humans that produce observations
Observation (o)Data returned after an action (tool result, user message, timer)
Action (a)Element of a closed or constrained action space (tool call, answer, escalate, …)
State (s)Structured system state (not only chat text)
Policy (\pi)Mapping from state (and context) to action distribution or choice; may be hybrid
Control loopobserve → decide → act → update state → (repeat / terminate)
Episode / caseOne bounded unit of work (e.g. ShopOps case O-1001)
Hybrid controlModel proposes; deterministic code constrains/permits/executes

Context & serving

TermMeaning
Context / working contextTokens presented to the model this call
Context assemblerComponent that builds context under budget + precedence
Token budgetHard/soft limit on assembled context
Context poisoningUntrusted or conflicting content steering behaviour
KV cacheCached key/value tensors for prior tokens during decoding
Prompt / prefix cacheReuse of billed/computed prefix across requests when prefix bytes stable
Lost-in-the-MiddleEmpirical drop in use of mid-context evidence

Tools & reliability

TermMeaning
ToolTyped side-effecting or read API exposed to the agent
Tool registryName → schema → handler catalog
ExecutorRuns tools after policy checks
Idempotency keyClient key making retries safe
Dry runExecute validation/path without committing side effects

State & memory

TermMeaning
FSMExplicit finite-state control
CheckpointDurable snapshot enabling resume
Working memoryShort-horizon task state
Semantic memoryLong-lived facts/embeddings
Episodic memoryRecords of past episodes
Procedural memoryHow-to skills / playbooks
RetrievalFetch external/knowledge docs (≠ memory write)
Memory controllerPolicy for what is written/forgotten/superseded
ProvenanceWhere a fact came from

Multi-agent & audit

TermMeaning
OrchestratorAssigns tasks, budgets, approvals — not “the smart one”
LedgerAppend-only ordered log of shared events/beliefs
ConflictContradictory assertions recorded as data
TraceStructured record of a run’s decisions and I/O
Audit / evidence packExportable justification for a consequential action

Governance

TermMeaning
Policy-as-codeDeterministic permit/deny rules versioned in code
HITLHuman-in-the-loop approval/escalation as architecture
InjectionUntrusted content influencing instructions/actions
AuthzAuthorization independent of the model

Product (running example)

TermMeaning
ShopOpsThe book’s e-commerce post-purchase operations system
CaseOne customer order exception / order-exception workflow instance
Intake / Resolution / Policy / Outreach agentsSpecialised ShopOps components (may be modules or processes)

Discouraged synonyms

AvoidPrefer
BrainModel / policy
Memory (unqualified)Name the type
Autonomous (default)Agent with explicit permissions
Agent for every functionModule / workflow step