afv-library/skills/developing-agentforce/references/agent-topic-map-diagrams.md

Agent Topic Map Diagrams Reference

Table of Contents

• Purpose and Context
• Fundamental Structure Rules
• Node Types and Agent Script Elements
• Topic Map Patterns
• Complete Example: Local_Info_Agent
• Validation Checklist
• Anti-patterns

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Purpose and Context

A Topic Map diagram is a Mermaid flowchart that visualizes an agent's topic graph structure. It shows the architecture of an agent before implementation, displaying:

• The start_agent topic_selector entry point
• All topics in the agent
• Topic transitions and routing logic
• Action calls within topics (with backing type: Apex, Prompt Template, Flow)
• Gating conditions (available_when expressions)
• Variable state changes
• Escalation and off-topic handling
• Conditional instructions based on variable values

Topic Map diagrams are the primary visual deliverable in an Agent Spec (design document) and serve both specification and comprehension purposes.

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Fundamental Structure Rules

Graph Orientation

• ALWAYS use graph TD (Top-Down orientation)
• Start with start_agent topic_selector at the top
• Topics flow downward from the selector
• Never use other orientations

Node Identification

• Use sequential capital letters (A, B, C, ...) for node IDs
• Start with A for start_agent
• Increment sequentially through topics and decisions
• Use descriptive labels within brackets

Flow Direction

• Primary flow moves top-to-bottom
• Use --> for standard transitions
• Label decision branches with |Label| syntax
• Separate paths for different topics

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Node Types and Agent Script Elements

Start Agent Topic Selector Node

Format: [start_agent<br/>topic_selector]

Represents the entry point where user input is evaluated and routed to appropriate topics.

%%{init: {'theme':'neutral'}}%%
graph TD
    A[start_agent<br/>topic_selector]

Topic Nodes

Format: [topic_name<br/>Topic]

Represents a topic within the agent.

%%{init: {'theme':'neutral'}}%%
graph TD
    A[start_agent<br/>topic_selector]
    B[order_status<br/>Topic]
    C[billing<br/>Topic]

Action Call Nodes

Format: [Call action_name<br/>backing: Type]

Backing types: Apex, Prompt Template, Flow

Example: [Call check_weather<br/>backing: Apex]

%%{init: {'theme':'neutral'}}%%
graph TD
    A[local_weather<br/>Topic] --> B[Call check_weather<br/>backing: Apex]

Decision/Gating Nodes

Use curly braces {} for conditions. Common formats:

• Variable availability gates: {Check: variable_name != empty?}
• Conditional instructions: {variable_name == value?}
• Topic transition logic: {user_intent matches?}

%%{init: {'theme':'neutral'}}%%
graph TD
    A[topic<br/>Topic] --> B{Check: guest_interests<br/>!= empty?}
    B -->|Yes| C[Call collect_events<br/>backing: Prompt Template]
    B -->|No| D[Ask for clarification]

Variable State Change Nodes

Format: [Set variable_name = value]

Shows state modifications that affect downstream behavior.

%%{init: {'theme':'neutral'}}%%
graph TD
    A[Call action] --> B[Set reservation_required<br/>= true]

Utility Call Nodes

Format: [Call @utils.name]

For escalation and system utilities.

%%{init: {'theme':'neutral'}}%%
graph TD
    A[escalation<br/>Topic] --> B[Call @utils.escalate]

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Topic Map Patterns

Basic Topic with Single Action

%%{init: {'theme':'neutral'}}%%
graph TD
    A[start_agent<br/>topic_selector]
    A -->|route to topic| B[simple_topic<br/>Topic]
    B --> C[Call do_action<br/>backing: Apex]
    C --> D[Continue]

Topic with Gating Condition

Available_when expressions prevent action execution until conditions are met.

%%{init: {'theme':'neutral'}}%%
graph TD
    A[topic_with_gate<br/>Topic]
    A --> B{Check: required_var<br/>!= empty?}
    B -->|No| C[Instruction: collect info first]
    B -->|Yes| D[Call action<br/>backing: Prompt Template]
    C --> E[Wait for input]
    E --> A

Topic with Conditional Instructions

Variable values control which instructions apply to a topic.

%%{init: {'theme':'neutral'}}%%
graph TD
    A[Call process_request<br/>backing: Flow]
    A --> B[Set status_flag = complete]
    B --> C{Check: status_flag<br/>== complete?}
    C -->|Yes| D[Apply conditional<br/>instructions]
    D --> E[Continue]

Topic Transitions

When logic determines a new topic should be active.

%%{init: {'theme':'neutral'}}%%
graph TD
    A[current_topic<br/>Topic]
    A --> B{Transition<br/>condition?}
    B -->|Yes| C[Transition to<br/>next_topic]
    C --> D[next_topic<br/>Topic]
    B -->|No| E[Continue in<br/>current_topic]

Off-Topic and Escalation Routing

How the agent handles out-of-scope requests.

%%{init: {'theme':'neutral'}}%%
graph TD
    A[start_agent<br/>topic_selector]
    A -->|out of scope| B[off_topic<br/>Topic]
    A -->|needs help| C[escalation<br/>Topic]
    B --> D[Instruction: redirect user]
    C --> E[Call @utils.escalate]

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Complete Example: Local_Info_Agent

This example demonstrates a complete Topic Map for a guest information agent with multiple topics, gating conditions, variable state, and escalation handling.

%%{init: {'theme':'neutral'}}%%
graph TD
    A[start_agent<br/>topic_selector]

    A -->|weather query| B[local_weather<br/>Topic]
    A -->|events query| C[local_events<br/>Topic]
    A -->|hours query| D[resort_hours<br/>Topic]
    A -->|unclear intent| E[ambiguous_question<br/>Topic]
    A -->|out of scope| F[off_topic<br/>Topic]
    A -->|needs escalation| G[escalation<br/>Topic]

    B --> B1[Call check_weather<br/>backing: Apex]
    B1 --> B2[Continue]

    C --> C1{Check: guest_interests<br/>!= empty?}
    C1 -->|No| C2[Instruction: collect guest interests]
    C1 -->|Yes| C3[Call check_events<br/>backing: Prompt Template]
    C2 --> C4[Pause for input]
    C4 --> C
    C3 --> C5[Continue]

    D --> D1[Call get_resort_hours<br/>backing: Flow]
    D1 --> D2[Set reservation_required<br/>= true]
    D2 --> D3{Check: reservation_required<br/>== true?}
    D3 -->|Yes| D4[Apply booking instructions]
    D3 -->|No| D5[Apply standard instructions]
    D4 --> D6[Continue]
    D5 --> D6

    E --> E1[Instruction: ask for clarification]
    E1 --> E2[Await user input]
    E2 --> A

    F --> F1[Instruction: explain available topics]
    F1 --> F2[Continue]

    G --> G1[Call @utils.escalate]
    G1 --> G2[Continue]

Topic Descriptions

local_weather: Provides weather information via Apex-backed action. No preconditions.

local_events: Requires guest_interests variable to be populated (gating: available_when guest_interests != ""). Calls Prompt Template-backed action only when gate is satisfied.

resort_hours: Calls Flow-backed action that sets reservation_required variable. Conditional instructions applied based on variable state: booking-specific guidance when true, standard guidance when false.

ambiguous_question: No actions. Requests clarification and routes back to start_agent.

off_topic: No actions. Explains available topics and continues conversation.

escalation: Calls @utils.escalate utility to route to human agent.

start_agent topic_selector: Routes incoming user input to appropriate topics based on intent.

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Validation Checklist

Before finalizing a Topic Map diagram:

• Uses graph TD syntax
• Starts with %%{init: {'theme':'neutral'}}%%
• start_agent topic_selector is node A at top
• Nodes use sequential capital letter IDs
• All topics labeled with [topic_name<br/>Topic] format
• Action calls include backing type (Apex, Prompt Template, Flow)
• Gating conditions shown as decision nodes with {Check: ...?} format
• Variable state changes explicitly labeled with [Set variable = value]
• Escalation uses [Call @utils.escalate] format
• All transition branches are labeled
• Diagram fits in 20-30 nodes
• Topic routing from start_agent is clear
• Off-topic and escalation paths are visible
• Conditional instruction logic is shown

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Anti-patterns

Don't

• Use graph LR or other orientations instead of graph TD
• Place start_agent anywhere except top (node A)
• Label actions without backing type information
• Use ambiguous decision node labels (avoid {Process?})
• Hide gating conditions in node descriptions instead of showing as decisions
• Omit variable state changes that affect downstream behavior
• Create topic routing without labels on the decision logic
• Mix topic nodes with action nodes at same level without clear containment
• Use custom color styling (breaks in dark mode)
• Leave off-topic and escalation paths out of diagram

Do

• Keep start_agent topic_selector at the top
• Show all topics reachable from start_agent
• Include backing type for every action call
• Make gating conditions explicit as decision nodes
• Show variable updates as separate nodes when they affect logic flow
• Label all transition branches
• Include off-topic and escalation topics
• Show conditional instructions with decision nodes
• Use %%{init: {'theme':'neutral'}}%% for light/dark mode compatibility
• Focus diagram on topic structure, not detailed action logic