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Documentation Index

Fetch the complete documentation index at: https://docs.asteragents.com/llms.txt

Use this file to discover all available pages before exploring further.

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What it does

The Call Agent tool allows your agents to communicate with and delegate tasks to other agents on the Aster platform. Perfect for creating agent workflows, specialized task delegation, and building complex multi-agent systems.

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Key features

  • Call any agent on your Aster platform
  • Continue conversations across multiple interactions
  • Maintain conversation threads for context
  • Access to called agent’s capabilities and knowledge
  • Seamless agent-to-agent communication

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Parameters

ParameterTypeRequiredDescription
messagestringYesThe message to send to the target agent
agentNamestringYesThe name of the agent to call (matched case-insensitively)
respondToThreadIdstringNoID of an existing thread to continue (creates new thread if not provided)

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Common use cases

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Specialized task delegation

message: "Analyze this sales data and create a summary report with key insights"
agentId: "data-analyst-agent-123"
Delegate data analysis to a specialized analytics agent.

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Multi-step workflows

message: "Generate a marketing email for our new product launch"
agentId: "marketing-agent-456"
respondToThreadId: "thread-789"
Continue a conversation thread for complex workflows.

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Expert consultation

message: "Review this code for security vulnerabilities and best practices"
agentId: "security-expert-agent-789"
Get expert review from specialized agents.

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Content creation pipeline

message: "Create a blog post outline about AI trends in 2024"
agentId: "content-writer-agent-101"
Start a content creation workflow with writing specialists.

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Quality assurance

message: "Review and fact-check this research report before publication"
agentId: "qa-agent-202"
respondToThreadId: "research-thread-303"
Add quality control steps to your workflows.

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Customer support escalation

message: "This customer has a complex technical issue that needs expert attention"
agentId: "technical-support-agent-404"
Escalate complex issues to specialized support agents.

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Agent collaboration patterns

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Sequential workflow

  1. Agent A calls Agent B for initial analysis
  2. Agent B returns results to Agent A
  3. Agent A calls Agent C for final processing
  4. Agent C delivers final output

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Parallel processing

  • Call multiple specialized agents simultaneously
  • Combine their outputs for comprehensive results
  • Useful for multi-perspective analysis

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Iterative refinement

  • Use respondToThreadId to continue conversations
  • Refine outputs through multiple interactions
  • Build complex solutions step by step

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Configuring callable agents

When you enable call_agent on an agent, you choose which agents it’s allowed to call: Allow all agents in organization (default) — The agent can call any non-deleted agent in the org. This is ideal when paired with Manage Agents, which lets the agent dynamically discover available agents at runtime. Select specific agents — Restrict the agent to a curated allowlist. Use the agent selector modal to pick exactly which agents are callable. This is better when you want tight control over which agents can be reached. Both modes are configured in Control Hub → Edit Agent → Call Agent tool section.

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Finding agents to call

Agents are called by name (not ID). The agent can discover names by:
  • Using Manage Agents with action: "list" to see all agents in the org
  • Having agent names included in its system prompt
  • Being told by the user which agent to call

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What you get back

  • Agent Response: The called agent’s complete response
  • Thread ID: Unique identifier for the conversation thread
  • Agent Info: Details about the called agent
  • Conversation Context: Full context of the interaction

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Best practices

  • Use clear, specific messages when calling agents
  • Include relevant context and background information
  • Use thread IDs to maintain conversation continuity
  • Choose the right agent for each specific task
  • Monitor agent interactions for workflow optimization
  • Set up proper agent permissions and access controls

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Troubleshooting

“Agent not found”
  • The agent name must match exactly (case-insensitive). Check spelling
  • If using a specific allowlist, verify the target agent is in the list
  • The target agent may have been deleted
“No callable agents configured”
  • The agent has call_agent enabled but is set to “Select specific agents” with none selected
  • Either toggle “Allow all agents” on, or select specific agents in the modal