1074 lines
47 KiB
Markdown
1074 lines
47 KiB
Markdown
# AgentCore.jl - AgentLoop Component Deep Dive
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## AgentLoop Architecture
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```
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┌─────────────────────────────────────────────────────────────────────────────┐
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│ AgentLoop Layer │
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└─────────────────────────────────────────────────────────────────────────────┘
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┌─────────────────────────────────────────────────────────────────────────────┐
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│ Public API │
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└─────────────────────────────────────────────────────────────────────────────┘
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agentLoop()
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├─ prompts: Vector{AgentMessage}
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├─ context: AgentContext
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├─ config: AgentLoopConfig
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├─ signal: Union{Nothing, AbortSignal}
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└─ stream_fn: StreamFn
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└─ Returns: EventStream
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agentLoopContinue()
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├─ context: AgentContext
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├─ config: AgentLoopConfig
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├─ signal: Union{Nothing, AbortSignal}
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└─ stream_fn: StreamFn
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└─ Returns: EventStream
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┌─────────────────────────────────────────────────────────────────────────────┐
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│ Data Flow with Type Transformations │
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└─────────────────────────────────────────────────────────────────────────────┘
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┌─────────────────────────────────────────────────────────────────────────────┐
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│ 1. runAgentLoop() ── Entry point for new conversation │
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│ Input: prompts::Vector{AgentMessage} │
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│ context::AgentContext (system_prompt, messages, tools) │
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│ config::AgentLoopConfig │
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│ Output: new_messages::Vector{AgentMessage} (appended prompts + turns) │
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│ │
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│ - Creates copy of prompts │
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│ - Appends prompts to context.messages │
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│ - Emits AgentStartEvent │
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│ - Emits TurnStartEvent │
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│ - Emits MessageStart/End for each prompt │
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│ - Calls runLoop() │
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└─────────────────────────────────────────────────────────────────────────────┘
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│
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▼
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┌─────────────────────────────────────────────────────────────────────────────┐
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│ 2. runLoop() ── Main event loop │
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│ Input: current_context::AgentContext │
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│ new_messages::Vector{AgentMessage} │
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│ Output: N/A (writes to new_messages and context.messages) │
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│ │
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│ ┌────────────────────────────────────────────────────────────────────┐ │
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│ │ while true (outer loop: follow-up messages) │ │
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│ │ has_more_tool_calls = true │ │
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│ │ while has_more_tool_calls || !isempty(pending_messages) │ │
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│ │ 1. Emit TurnStartEvent (on subsequent turns) │ │
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│ │ 2. If pending_messages: emit MessageStart/End, drain queue │ │
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│ │ 3. streamAssistantResponse() │ │
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│ │ 4. If error/aborted: emit TurnEnd, AgentEnd, return │ │
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│ │ 5. Execute tool calls (sequential or parallel) │ │
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│ │ 6. has_more_tool_calls = !batch.terminate │ │
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│ │ 7. Emit TurnEndEvent │ │
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│ │ 8. prepare_next_turn (optional config update) │ │
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│ │ 9. should_stop_after_turn? (early return) │ │
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│ │ 10. pending_messages = get_steering_messages() │ │
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│ │ if !isempty(get_follow_up_messages()) → continue outer loop │ │
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│ │ break │ │
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│ │ emit AgentEndEvent │ │
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│ └────────────────────────────────────────────────────────────────────┘ │
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└─────────────────────────────────────────────────────────────────────────────┘
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│
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▼
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┌─────────────────────────────────────────────────────────────────────────────┐
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│ 3. streamAssistantResponse() ── LLM interaction │
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│ Input: context::AgentContext │
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│ config::AgentLoopConfig │
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│ Output: message::AssistantMessage │
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│ │
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│ Data Transformations: │
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│ ┌────────────────────────────────────────────────────────────────────┐ │
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│ │ Step 1: transform_context (optional) │ │
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│ │ Input: context.messages::Vector{AgentMessage} │ │
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│ │ Output: messages::Vector{AgentMessage} (transformed) │ │
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│ │ │ │
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│ │ Step 2: convert_to_llm │ │
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│ │ Input: messages::Vector{AgentMessage} │ │
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│ │ Output: llm_messages::Vector{Message} │ │
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│ │ - UserMessage → UserMessage │ │
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│ │ - AssistantMessage → AssistantMessage │ │
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│ │ - ToolResultMessage → ToolResultMessage │ │
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│ │ - BashExecutionMessage → UserMessage │ │
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│ │ - CompactionSummaryMessage → UserMessage │ │
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│ │ - BranchSummaryMessage → UserMessage │ │
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│ │ │ │
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│ │ Step 3: Call stream_fn │ │
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│ │ Input: model, llm_context::Context, config │ │
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│ │ Output: response::Stream (events) │ │
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│ │ │ │
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│ │ Step 4: Stream events │ │
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│ │ Events: start, text_start/delta/end, toolcall_start/delta/end │ │
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│ │ Final: AssistantMessage (with ToolCall[] in content) │ │
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│ └────────────────────────────────────────────────────────────────────┘ │
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└─────────────────────────────────────────────────────────────────────────────┘
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│
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▼
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┌─────────────────────────────────────────────────────────────────────────────┐
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│ 4. executeToolCalls() ── Tool execution │
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│ Input: assistant_message::AssistantMessage (contains ToolCall[]) │
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│ current_context::AgentContext │
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│ Output: ExecutedToolCallBatch (messages::ToolResultMessage[], terminate) │
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│ │
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│ For each ToolCall: │
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│ ┌────────────────────────────────────────────────────────────────────┐ │
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│ │ prepareToolCall() │ │
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│ │ Input: tool_call::ToolCall │ │
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│ │ Output: PreparedToolCall or ImmediateToolCallOutcome │ │
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│ │ - validates arguments │ │
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│ │ - runs before_tool_call hook (optional) │ │
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│ │ - runs prepare_arguments hook (optional) │ │
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│ │ │ │
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│ │ executePreparedToolCall() (if prepared) │ │
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│ │ Input: PreparedToolCall │ │
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│ │ Output: ExecutedToolCallOutcome │ │
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│ │ - calls tool.execute() │ │
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│ │ - returns AgentToolResultMutable │ │
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│ │ │ │
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│ │ finalizeExecutedToolCall() │ │
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│ │ Input: ExecutedToolCallOutcome │ │
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│ │ Output: FinalizedToolCallOutcome │ │
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│ │ - runs after_tool_call hook (optional) │ │
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│ │ - returns ToolCall + AgentToolResultMutable + is_error │ │
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│ │ │ │
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│ │ createToolResultMessage() │ │
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│ │ Input: FinalizedToolCallOutcome │ │
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│ │ Output: ToolResultMessage │ │
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│ │ - role: "toolResult" │ │
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│ │ - tool_call_id, tool_name, content, details │ │
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│ │ - usage, added_tool_names, is_error, timestamp │ │
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│ └────────────────────────────────────────────────────────────────────┘ │
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│ │
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│ ┌────────────────────────────────────────────────────────────────────┐ │
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│ │ Sequential: executeToolCallsSequential() │ │
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│ │ - Executes tools one at a time, waits for each │ │
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│ │ - Returns batch of ToolResultMessage[] │ │
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│ │ │ │
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│ │ Parallel: executeToolCallsParallel() │ │
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│ │ - Creates closures for async execution │ │
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│ │ - Executes all closures, collects results │ │
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│ │ - Returns batch of ToolResultMessage[] │ │
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│ └────────────────────────────────────────────────────────────────────┘ │
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└─────────────────────────────────────────────────────────────────────────────┘
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│
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▼
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┌─────────────────────────────────────────────────────────────────────────────┐
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│ 5. AgentEndEvent ── Final event with all messages │
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│ Output: messages::Vector{AgentMessage} │
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│ Contains: [UserMessage, AssistantMessage, ToolResultMessage, ...] │
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└─────────────────────────────────────────────────────────────────────────────┘
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```
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## AgentLoopConfig
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```julia
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struct AgentLoopConfig
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model::Model
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reasoning::Union{ThinkingLevel, Nothing}
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session_id::Union{String, Nothing}
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on_payload::Union{Function, Nothing}
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on_response::Union{Function, Nothing}
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transport::String
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thinking_budgets::Union{Dict{String, Int64}, Nothing}
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max_retry_delay_ms::Union{Int64, Nothing}
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tool_execution::ToolExecutionMode
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before_tool_call::Union{Function, Nothing}
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after_tool_call::Union{Function, Nothing}
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prepare_next_turn::Union{Function, Nothing}
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convert_to_llm::Function
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transform_context::Union{Function, Nothing}
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get_api_key::Union{Function, Nothing}
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get_steering_messages::Union{Function, Nothing}
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get_follow_up_messages::Union{Function, Nothing}
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should_stop_after_turn::Union{Function, Nothing}
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max_tokens::Union{Int64, Nothing}
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temperature::Union{Float64, Nothing}
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cache_retention::Union{String, Nothing}
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headers::Union{Dict{String, String}, Nothing}
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metadata::Union{Dict{String, Any}, Nothing}
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signal::Union{Any, Nothing}
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api_key::Union{String, Nothing}
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end
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```
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**Notes:**
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- `should_stop_after_turn(context::PrepareNextTurnContext)::Bool` — Default returns `false`. Use to implement custom termination logic (e.g., max turns, tool-specific termination).
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- `max_tokens`, `temperature`, `cache_retention` — Passed through to the LLM API provider.
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- `signal`, `api_key` — Per-request overrides for abort handling and authentication.
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- `headers`, `metadata` — Passed through to the LLM API provider.
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## Main Functions
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### agentLoop()
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```julia
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function agentLoop(
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prompts::Vector{AgentMessage},
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context::AgentContext,
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config::AgentLoopConfig,
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signal::Union{Nothing, AbortSignal},
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stream_fn::StreamFn,
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)::EventStream
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```
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**Purpose**: Start a new conversation with initial prompts
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**Flow**:
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1. Create event stream
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2. Spawn thread to run agent loop
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3. Return stream for event consumption
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```julia
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stream = agentLoop(
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[UserMessage("user", [TextContent("Hello")], timestamp)],
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AgentContext(system_prompt, messages, tools),
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config,
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nothing,
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stream_fn,
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)
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# Consume events
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for event in stream
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if event isa MessageEndEvent
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println("Received: $(event.message)")
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end
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end
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```
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### runAgentLoop()
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```julia
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function runAgentLoop(
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prompts::Vector{AgentMessage},
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context::AgentContext,
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config::AgentLoopConfig,
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emit::AgentEventSink,
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signal::Union{Nothing, AbortSignal},
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stream_fn::StreamFn,
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)::Vector{AgentMessage}
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```
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**Purpose**: Execute agent loop with initial prompts
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**Flow**:
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1. Copy prompts to `new_messages`
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2. Create `current_context` with prompts appended to `context.messages`
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3. Emit `AgentStartEvent`
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4. Emit `TurnStartEvent`
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5. For each prompt: emit `MessageStartEvent`, `MessageEndEvent`
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6. Call `runLoop()` — handles the main loop, tool execution, and termination
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7. Return `new_messages`
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### runLoop() - The Heart of AgentLoop
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```julia
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function runLoop(
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initial_context::AgentContext,
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new_messages::Vector{AgentMessage},
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initial_config::AgentLoopConfig,
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signal::Union{Nothing, AbortSignal},
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emit::AgentEventSink,
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stream_function::StreamFn,
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)::Nothing
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```
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**Main Loop** (simplified — shows structure; actual code has type annotations):
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```julia
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current_context = initial_context
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config = initial_config
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first_turn = true
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pending_messages = get_steering_messages(config)
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while true
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has_more_tool_calls = true
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# Inner loop: process pending messages AND/OR tool results
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while has_more_tool_calls || !isempty(pending_messages)
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if !first_turn
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emit(TurnStartEvent())
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else
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first_turn = false
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end
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# Emit pending messages (steering / follow-up)
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if !isempty(pending_messages)
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for message in pending_messages
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emit(MessageStartEvent(message))
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emit(MessageEndEvent(message))
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push!(current_context.messages, message)
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push!(new_messages, message)
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end
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pending_messages = AgentMessage[]
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end
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# Stream assistant response
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message = streamAssistantResponse(
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current_context, config, signal, emit, stream_function
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)
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push!(new_messages, message)
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# Early exit on error/abort
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if message.stop_reason in ("error", "aborted")
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emit(TurnEndEvent(message, ToolResultMessage[]))
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emit(AgentEndEvent(new_messages))
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return
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end
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# Execute tool calls (if any)
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tool_calls = filter(c -> c isa ToolCall, message.content)
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tool_results = ToolResultMessage[]
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has_more_tool_calls = false
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if !isempty(tool_calls)
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executed_batch = if message.stop_reason == "length"
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failToolCallsFromTruncatedMessage(tool_calls, emit)
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else
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executeToolCalls(
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current_context, message, config, signal, emit
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)
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end
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append!(tool_results, executed_batch.messages)
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has_more_tool_calls = !executed_batch.terminate
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for result in tool_results
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push!(current_context.messages, result)
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push!(new_messages, result)
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end
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end
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emit(TurnEndEvent(message, tool_results))
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# Optional: prepare next turn (model/thinking/context changes)
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next_turn_context = PrepareNextTurnContext(
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message, tool_results, current_context, new_messages
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)
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next_turn_snapshot = prepare_next_turn(config, next_turn_context)
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if !isnothing(next_turn_snapshot)
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current_context = next_turn_snapshot.context
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# Rebuild config with updated model/thinking + preserved fields
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config = AgentLoopConfig(
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model = next_turn_snapshot.model,
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reasoning = next_turn_snapshot.thinking_level,
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convert_to_llm = config.convert_to_llm,
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transform_context = config.transform_context,
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get_api_key = config.get_api_key,
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should_stop_after_turn = config.should_stop_after_turn,
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prepare_next_turn = config.prepare_next_turn,
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get_steering_messages = config.get_steering_messages,
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get_follow_up_messages = config.get_follow_up_messages,
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tool_execution = config.tool_execution,
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before_tool_call = config.before_tool_call,
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after_tool_call = config.after_tool_call,
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max_tokens = config.max_tokens,
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temperature = config.temperature,
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reasoning = config.reasoning,
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cache_retention = config.cache_retention,
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session_id = config.session_id,
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headers = config.headers,
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metadata = config.metadata,
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transport = config.transport,
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signal = signal,
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api_key = config.api_key,
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on_payload = config.on_payload,
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on_response = config.on_response,
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max_retry_delay_ms = config.max_retry_delay_ms,
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)
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end
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# Check termination
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if should_stop_after_turn(config, next_turn_context)
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emit(AgentEndEvent(new_messages))
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return
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end
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# Get next steering messages
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pending_messages = get_steering_messages(config)
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end
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# Check follow-up messages (processed only after all tool calls complete)
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follow_up_messages = get_follow_up_messages(config)
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if !isempty(follow_up_messages)
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pending_messages = follow_up_messages
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continue
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end
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break
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end
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emit(AgentEndEvent(new_messages))
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```
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### streamAssistantResponse()
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```julia
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function streamAssistantResponse(
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context::AgentContext,
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config::AgentLoopConfig,
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signal::Union{Nothing, AbortSignal},
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emit::AgentEventSink,
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stream_function::StreamFn,
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)::AssistantMessage
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```
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**Data Flow**:
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```
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Input: context.messages::Vector{AgentMessage}
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↓
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[transform_context] (optional hook)
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↓
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messages::Vector{AgentMessage}
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↓
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[convert_to_llm] - Type transformation pipeline
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↓
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llm_messages::Vector{Message}
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│
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│ AgentMessage → Message mapping:
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│ • UserMessage → UserMessage (pass-through)
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│ • AssistantMessage → AssistantMessage (pass-through)
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│ • ToolResultMessage → ToolResultMessage (pass-through)
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│ • BashExecutionMessage → UserMessage (text conversion)
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│ • CompactionSummaryMessage → UserMessage (text wrapped)
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│ • BranchSummaryMessage → UserMessage (text wrapped)
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│
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▼
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Context(system_prompt, llm_messages, tools)
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↓
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stream_fn(model, context, config) - LLM API call
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↓
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Stream of AssistantMessageEvent:
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• StartEvent (partial AssistantMessage)
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• TextStartEvent/TextDeltaEvent/TextEndEvent
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• ToolCallStartEvent/ToolCallDeltaEvent/ToolCallEndEvent
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• DoneEvent (final AssistantMessage with usage, stop_reason)
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↓
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Return: AssistantMessage
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- content::Vector{MessageContent}
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- usage::Usage
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- stop_reason::String
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- Contains ToolCall[] if tool calls requested
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```
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### executeToolCalls()
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```julia
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function executeToolCalls(
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current_context::AgentContext,
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assistant_message::AssistantMessage,
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config::AgentLoopConfig,
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signal::Union{Nothing, AbortSignal},
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emit::AgentEventSink,
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)::ExecutedToolCallBatch
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```
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**Data Flow**:
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```
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Input: assistant_message::AssistantMessage
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- content::Vector{MessageContent}
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└─ Contains ToolCall[] and/or TextContent[]
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↓
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filter(c -> c isa ToolCall, assistant_message.content)
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↓
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tool_calls::Vector{ToolCall}
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- type: "tool"
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- id::String
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- name::String
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- arguments::Dict{String, Any}
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- partial_json::Union{String, Nothing}
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↓
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Check execution mode:
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• config.tool_execution (sequential/parallel)
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• Any tool.execution_mode == EXECUTION_SEQUENTIAL?
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↓
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┌─────────────────────────────────────────────────────────────────┐
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│ Sequential Mode (or has_sequential_tool) │
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│ For each tool_call in tool_calls: │
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│ prepareToolCall() → PreparedToolCall │
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│ executePreparedToolCall() → ExecutedToolCallOutcome │
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│ finalizeExecutedToolCall() → FinalizedToolCallOutcome │
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│ createToolResultMessage() → ToolResultMessage │
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│ (wait for completion before next tool) │
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└─────────────────────────────────────────────────────────────────┘
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↓
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┌─────────────────────────────────────────────────────────────────┐
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│ Parallel Mode │
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│ For each tool_call in tool_calls: │
|
|
│ prepareToolCall() → (PreparedToolCall | ImmediateOutcome) │
|
|
│ If prepared: create closure │
|
|
│ If immediate: execute and add to finalized_calls │
|
|
│ │
|
|
│ For each entry in finalized_calls: │
|
|
│ If closure: execute closure │
|
|
│ If finalized: use as-is │
|
|
└─────────────────────────────────────────────────────────────────┘
|
|
↓
|
|
ExecutedToolCallBatch
|
|
- messages::Vector{ToolResultMessage}
|
|
- terminate::Bool (true if all tools have terminate=true)
|
|
```
|
|
|
|
### executeToolCallsSequential()
|
|
|
|
```julia
|
|
function executeToolCallsSequential(
|
|
current_context::AgentContext,
|
|
assistant_message::AssistantMessage,
|
|
tool_calls::Vector{ToolCall},
|
|
config::AgentLoopConfig,
|
|
signal::Union{Nothing, AbortSignal},
|
|
emit::AgentEventSink,
|
|
)::ExecutedToolCallBatch
|
|
```
|
|
|
|
**Flow** (for each tool call):
|
|
1. Emit ToolExecutionStartEvent
|
|
2. prepareToolCall() → PreparedToolCall or ImmediateToolCallOutcome
|
|
3. If prepared: executePreparedToolCall()
|
|
4. finalizeExecutedToolCall()
|
|
5. Emit ToolExecutionEndEvent
|
|
6. Emit ToolResultMessage
|
|
7. Check if signal.aborted → break
|
|
|
|
### executeToolCallsParallel()
|
|
|
|
```julia
|
|
function executeToolCallsParallel(
|
|
current_context::AgentContext,
|
|
assistant_message::AssistantMessage,
|
|
tool_calls::Vector{ToolCall},
|
|
config::AgentLoopConfig,
|
|
signal::Union{Nothing, AbortSignal},
|
|
emit::AgentEventSink,
|
|
)::ExecutedToolCallBatch
|
|
```
|
|
|
|
**Flow**:
|
|
1. For each tool call:
|
|
- If immediate: execute and add to finalized_calls
|
|
- If prepared: create closure, add to finalized_calls
|
|
2. For each entry in finalized_calls:
|
|
- If closure: execute closure
|
|
- If finalized: use as-is
|
|
3. Collect all tool results
|
|
4. Return batch
|
|
|
|
### prepareToolCall()
|
|
|
|
```julia
|
|
function prepareToolCall(
|
|
current_context::AgentContext,
|
|
assistant_message::AssistantMessage,
|
|
tool_call::ToolCall,
|
|
config::AgentLoopConfig,
|
|
signal::Union{Nothing, AbortSignal},
|
|
)::Union{PreparedToolCall, ImmediateToolCallOutcome}
|
|
```
|
|
|
|
**Data Flow**:
|
|
|
|
```
|
|
Input: tool_call::ToolCall
|
|
- id::String
|
|
- name::String
|
|
- arguments::Dict{String, Any}
|
|
↓
|
|
findfirst(t -> t.name == tool_call.name, current_context.tools)
|
|
↓
|
|
If tool is nothing:
|
|
→ ImmediateToolCallOutcome("immediate", error_result, is_error=true)
|
|
↓
|
|
If tool exists:
|
|
[before_tool_call hook] (optional)
|
|
Input: BeforeToolCallContext(assistant_message, tool_call, args, context)
|
|
Output: BeforeToolCallResult (block, reason) or nothing
|
|
If block=true → ImmediateToolCallOutcome(error)
|
|
↓
|
|
prepareToolCallArguments(tool, tool_call)
|
|
Input: tool_call.arguments::Dict{String, Any}
|
|
Output: prepared_arguments::Any
|
|
(Optional: transform arguments before validation)
|
|
↓
|
|
validateToolArguments(tool, prepared_tool_call)
|
|
Input: prepared_tool_call.arguments
|
|
Output: validated_args::Any
|
|
(Optional: JSON schema validation)
|
|
↓
|
|
Return: PreparedToolCall("prepared", tool_call, tool, validated_args)
|
|
- kind: "prepared"
|
|
- tool_call: ToolCall (original)
|
|
- tool: AgentTool
|
|
- args: validated arguments
|
|
```
|
|
|
|
### executePreparedToolCall()
|
|
|
|
```julia
|
|
function executePreparedToolCall(
|
|
prepared::PreparedToolCall,
|
|
signal::Union{Nothing, AbortSignal},
|
|
emit::AgentEventSink,
|
|
)::ExecutedToolCallOutcome
|
|
```
|
|
|
|
**Data Flow**:
|
|
|
|
```
|
|
Input: prepared::PreparedToolCall
|
|
- tool_call::ToolCall
|
|
- tool::AgentTool
|
|
- args::Any (validated)
|
|
↓
|
|
tool.execute(tool_call.id, args, signal, on_update)
|
|
Input: tool_call_id::String
|
|
args::Any
|
|
signal::Union{Any, Nothing}
|
|
on_update::Function (partial_result → void)
|
|
Output: AgentToolResultMutable (defined in agent_loop.jl)
|
|
- content::Vector{MessageContent}
|
|
- details::Any
|
|
- usage::Union{Usage, Nothing}
|
|
- added_tool_names::Union{Vector{String}, Nothing}
|
|
- terminate::Union{Bool, Nothing}
|
|
↓
|
|
Note: tool.execute signature is
|
|
(tool_call_id, args, signal, on_update, context)
|
|
where context is the tool's captured context closure parameter
|
|
↓
|
|
Collect update events from on_update callbacks
|
|
↓
|
|
Return: ExecutedToolCallOutcome(result, is_error=false)
|
|
- result::AgentToolResultMutable
|
|
```
|
|
|
|
### finalizeExecutedToolCall()
|
|
|
|
```julia
|
|
function finalizeExecutedToolCall(
|
|
current_context::AgentContext,
|
|
assistant_message::AssistantMessage,
|
|
prepared::PreparedToolCall,
|
|
executed::ExecutedToolCallOutcome,
|
|
config::AgentLoopConfig,
|
|
signal::Union{Nothing, AbortSignal},
|
|
)::FinalizedToolCallOutcome
|
|
```
|
|
|
|
**Data Flow**:
|
|
|
|
```
|
|
Input: executed::ExecutedToolCallOutcome
|
|
- result::AgentToolResultMutable
|
|
- is_error::Bool
|
|
↓
|
|
[after_tool_call hook] (optional)
|
|
Input: AfterToolCallContext(
|
|
assistant_message,
|
|
tool_call,
|
|
args,
|
|
result,
|
|
is_error,
|
|
context
|
|
)
|
|
Output: AfterToolCallResult (optional patches)
|
|
- content::Union{Vector{MessageContent}, Nothing}
|
|
- details::Union{Any, Nothing}
|
|
- is_error::Union{Bool, Nothing}
|
|
- usage::Union{Usage, Nothing}
|
|
- terminate::Union{Bool, Nothing}
|
|
↓
|
|
Apply patches to result (if patches not nothing, replace non-nothing fields)
|
|
result = AgentToolResultMutable(
|
|
patches.content != nothing ? patches.content : result.content,
|
|
patches.details != nothing ? patches.details : result.details,
|
|
patches.usage != nothing ? patches.usage : result.usage,
|
|
result.added_tool_names, # not patched
|
|
patches.terminate != nothing ? patches.terminate : result.terminate,
|
|
)
|
|
is_error = patches.is_error != nothing ? patches.is_error : is_error
|
|
↓
|
|
Return: FinalizedToolCallOutcome
|
|
- tool_call::ToolCall (original)
|
|
- result::AgentToolResultMutable (final)
|
|
- is_error::Bool
|
|
```
|
|
|
|
### createToolResultMessage()
|
|
|
|
```julia
|
|
function createToolResultMessage(
|
|
finalized::FinalizedToolCallOutcome,
|
|
)::ToolResultMessage
|
|
```
|
|
|
|
**Data Flow**:
|
|
|
|
```
|
|
Input: finalized::FinalizedToolCallOutcome
|
|
- tool_call::ToolCall
|
|
- result::AgentToolResultMutable
|
|
- content::Vector{MessageContent}
|
|
- details::Any
|
|
- usage::Union{Usage, Nothing}
|
|
- added_tool_names::Union{Vector{String}, Nothing}
|
|
- is_error::Bool
|
|
↓
|
|
Build ToolResultMessage:
|
|
• role: "toolResult"
|
|
• tool_call_id: tool_call.id
|
|
• tool_name: tool_call.name
|
|
• content: result.content
|
|
• details: result.details
|
|
• usage: result.usage
|
|
• added_tool_names: result.added_tool_names
|
|
• is_error: is_error
|
|
• timestamp: Int64(Dates.now(Dates.UTC).datetime)
|
|
↓
|
|
Output: ToolResultMessage
|
|
- role::String ("toolResult")
|
|
- tool_call_id::String
|
|
- tool_name::String
|
|
- content::Vector{MessageContent}
|
|
- details::Any
|
|
- usage::Union{Usage, Nothing}
|
|
- added_tool_names::Union{Vector{String}, Nothing}
|
|
- is_error::Bool
|
|
- timestamp::Timestamp (Int64)
|
|
```
|
|
|
|
## Execution Modes
|
|
|
|
### Sequential Execution
|
|
|
|
```
|
|
┌─────────────────────────────────────────────────────────────────────────┐
|
|
│ Sequential Execution Flow (Strict Order) │
|
|
└─────────────────────────────────────────────────────────────────────────┘
|
|
|
|
TC1 TC2 TC3
|
|
│ │ │
|
|
▼ ▼ ▼
|
|
┌──────────────────┐ ┌──────────────────┐ ┌──────────────────┐
|
|
│ prepareToolCall()│───▶│ prepareToolCall()│───▶│ prepareToolCall()│
|
|
└──────────────────┘ └──────────────────┘ └──────────────────┘
|
|
│ │ │
|
|
▼ ▼ ▼
|
|
┌──────────────────┐ ┌──────────────────┐ ┌──────────────────┐
|
|
│ execute() │ │ execute() │ │ execute() │
|
|
│ (blocking) │ │ (blocking) │ │ (blocking) │
|
|
└──────────────────┘ └──────────────────┘ └──────────────────┘
|
|
│ │ │
|
|
▼ ▼ ▼
|
|
┌──────────────────┐ ┌──────────────────┐ ┌──────────────────┐
|
|
│ finalize() │ │ finalize() │ │ finalize() │
|
|
│ + emit events │ │ + emit events │ │ + emit events │
|
|
└──────────────────┘ └──────────────────┘ └──────────────────┘
|
|
│ │ │
|
|
▼ ▼ ▼
|
|
Result1 Result2 Result3
|
|
│ │ │
|
|
└───────────────────────┴───────────────────────┘
|
|
│
|
|
▼
|
|
┌────────────────────────┐
|
|
│ ExecutedToolCallBatch │
|
|
│ (Result1, Result2, │
|
|
│ Result3, terminate) │
|
|
└────────────────────────┘
|
|
```
|
|
|
|
### Parallel Execution
|
|
|
|
```
|
|
┌─────────────────────────────────────────────────────────────────────────┐
|
|
│ Parallel Execution Flow │
|
|
└─────────────────────────────────────────────────────────────────────────┘
|
|
|
|
┌──────┐
|
|
│ TC1 │ ──► prepareToolCall() ──► create closure ──► ┐
|
|
└──────┘ │
|
|
│
|
|
┌──────┐ │
|
|
│ TC2 │ ──► prepareToolCall() ──► create closure ──► ├─► All closures queued
|
|
└──────┘ │
|
|
│
|
|
┌──────┐ │
|
|
│ TC3 │ ──► prepareToolCall() ──► create closure ──► ┘
|
|
└──────┘
|
|
|
|
│
|
|
▼
|
|
┌───────────────────────┐
|
|
│ for closure in closures│
|
|
│ execute_closure() │
|
|
└───────────────────────┘
|
|
│
|
|
▼
|
|
┌───────────────────────┐
|
|
│ Collect all results │
|
|
└───────────────────────┘
|
|
│
|
|
▼
|
|
┌───────────────────────┐
|
|
│ createToolResult() │
|
|
└───────────────────────┘
|
|
```
|
|
|
|
## Helper Types
|
|
|
|
### ExecutedToolCallBatch
|
|
|
|
```julia
|
|
struct ExecutedToolCallBatch
|
|
messages::Vector{ToolResultMessage}
|
|
terminate::Bool
|
|
end
|
|
```
|
|
|
|
- `messages`: All tool result messages
|
|
- `terminate`: If true, stop agent after this batch
|
|
|
|
### PrepareNextTurnContext
|
|
|
|
```julia
|
|
struct PrepareNextTurnContext
|
|
message::AssistantMessage
|
|
tool_results::Vector{ToolResultMessage}
|
|
context::AgentContext
|
|
new_messages::Vector{AgentMessage}
|
|
end
|
|
```
|
|
|
|
Used by prepare_next_turn hook to decide next steps.
|
|
|
|
### Before/After Tool Call Contexts
|
|
|
|
```julia
|
|
struct BeforeToolCallContext
|
|
assistant_message::AssistantMessage
|
|
tool_call::ToolCall
|
|
args::Any
|
|
context::AgentContext
|
|
end
|
|
|
|
struct BeforeToolCallResult
|
|
block::Union{Bool, Nothing}
|
|
reason::Union{String, Nothing}
|
|
end
|
|
|
|
struct AfterToolCallContext
|
|
assistant_message::AssistantMessage
|
|
tool_call::ToolCall
|
|
args::Any
|
|
result::AgentToolResult
|
|
is_error::Bool
|
|
context::AgentContext
|
|
end
|
|
|
|
struct AfterToolCallResult
|
|
content::Union{Vector{MessageContent}, Nothing}
|
|
details::Union{Any, Nothing}
|
|
is_error::Union{Bool, Nothing}
|
|
usage::Union{Usage, Nothing}
|
|
terminate::Union{Bool, Nothing}
|
|
end
|
|
```
|
|
|
|
## Event Emission Timeline
|
|
|
|
```
|
|
AgentStartEvent
|
|
│
|
|
├─ TurnStartEvent (turn 1)
|
|
│ │
|
|
│ ├─ MessageStartEvent (user prompt)
|
|
│ ├─ MessageEndEvent (user prompt)
|
|
│ │
|
|
│ ├─ MessageStartEvent (assistant)
|
|
│ ├─ MessageUpdateEvent (text delta)
|
|
│ ├─ MessageUpdateEvent (tool call delta)
|
|
│ ├─ MessageEndEvent (assistant)
|
|
│ │
|
|
│ ├─ ToolExecutionStartEvent (tc1)
|
|
│ ├─ ToolExecutionEndEvent (tc1)
|
|
│ │
|
|
│ ├─ ToolExecutionStartEvent (tc2)
|
|
│ ├─ ToolExecutionEndEvent (tc2)
|
|
│ │
|
|
│ └─ TurnEndEvent (assistant, tool_results)
|
|
│
|
|
├─ TurnStartEvent (turn 2 - if needed)
|
|
│ │
|
|
│ ├─ MessageStartEvent (steering/follow-up)
|
|
│ ├─ MessageEndEvent (steering/follow-up)
|
|
│ │
|
|
│ ├─ MessageStartEvent (assistant)
|
|
│ ├─ MessageUpdateEvent (text)
|
|
│ ├─ MessageEndEvent (assistant)
|
|
│ │
|
|
│ └─ TurnEndEvent (assistant, [])
|
|
│
|
|
└─ AgentEndEvent (final messages)
|
|
```
|
|
|
|
## Key Concepts
|
|
|
|
### 1. Message Transformation Pipeline
|
|
|
|
```
|
|
Vector{AgentMessage} (internal conversation history)
|
|
│
|
|
├─ transform_context() (optional hook)
|
|
│ Input: Vector{AgentMessage}
|
|
│ Output: Vector{AgentMessage} (transformed)
|
|
│
|
|
└─ convert_to_llm()
|
|
│
|
|
│ Type mapping (single dispatch):
|
|
│ • UserMessage → UserMessage (pass-through)
|
|
│ • AssistantMessage → AssistantMessage (pass-through)
|
|
│ • ToolResultMessage → ToolResultMessage (pass-through)
|
|
│ • BashExecutionMessage → UserMessage (text conversion)
|
|
│ • CompactionSummaryMessage → UserMessage (text wrapped)
|
|
│ • BranchSummaryMessage → UserMessage (text wrapped)
|
|
│
|
|
▼
|
|
Vector{Message} (for LLM API)
|
|
```
|
|
|
|
### 2. Tool Call Lifecycle (with Data Transformations)
|
|
|
|
```
|
|
ToolCall (in AssistantMessage.content)
|
|
│
|
|
├─ before_tool_call hook (optional)
|
|
│ Input: BeforeToolCallContext(
|
|
│ assistant_message::AssistantMessage,
|
|
│ tool_call::ToolCall,
|
|
│ args::Dict{String, Any},
|
|
│ context::AgentContext
|
|
│ )
|
|
│ Output: BeforeToolCallResult (block, reason) or nothing
|
|
│
|
|
├─ prepareToolCall()
|
|
│ Input: tool_call::ToolCall
|
|
│ Output: Union{PreparedToolCall, ImmediateToolCallOutcome}
|
|
│ • PreparedToolCall (kind, tool_call, tool, args)
|
|
│ • ImmediateToolCallOutcome (immediate, result, is_error)
|
|
│
|
|
├─ executePreparedToolCall() (if prepared)
|
|
│ Input: PreparedToolCall
|
|
│ Output: ExecutedToolCallOutcome
|
|
│ tool.execute() returns AgentToolResultMutable
|
|
│ • content::Vector{MessageContent}
|
|
│ • details::Any
|
|
│ • usage::Union{Usage, Nothing}
|
|
│ • terminate::Union{Bool, Nothing}
|
|
│
|
|
├─ finalizeExecutedToolCall()
|
|
│ Input: ExecutedToolCallOutcome
|
|
│ Output: FinalizedToolCallOutcome
|
|
│ • tool_call::ToolCall
|
|
│ • result::AgentToolResultMutable
|
|
│ • is_error::Bool
|
|
│
|
|
└─ createToolResultMessage()
|
|
Input: FinalizedToolCallOutcome
|
|
Output: ToolResultMessage
|
|
• role: "toolResult"
|
|
• tool_call_id, tool_name
|
|
• content::Vector{MessageContent}
|
|
• details, usage, added_tool_names
|
|
• is_error, timestamp
|
|
```
|
|
|
|
### 3. Turn Termination
|
|
|
|
```julia
|
|
# The outer while-true loop exits when:
|
|
# 1. No pending messages AND no tool results to reprocess (inner loop ends)
|
|
# 2. No follow-up messages to queue
|
|
# 3. should_stop_after_turn() returns true (checked after each tool-call batch)
|
|
|
|
# Termination conditions:
|
|
# - message.stop_reason in ("error", "aborted") → immediate return
|
|
# - should_stop_after_turn() hook returns true → return AgentEndEvent
|
|
# - tool result batch has terminate=true → has_more_tool_calls = false, exit inner loop
|
|
# - No pending messages, no follow-up messages → break outer loop
|
|
```
|
|
|
|
## Best Practices
|
|
|
|
1. **Use sequential execution** for tools that modify shared state
|
|
2. **Use parallel execution** for independent tool calls (better performance)
|
|
3. **Implement prepare_next_turn** for dynamic model/thinking level changes
|
|
4. **Use before_tool_call** for logging or blocking sensitive operations
|
|
5. **Use after_tool_call** for modifying results or collecting metrics
|
|
|
|
## Complete Example
|
|
|
|
```julia
|
|
using AgentCore
|
|
|
|
# Create config
|
|
config = AgentLoopConfig(
|
|
model = my_model,
|
|
reasoning = THINKING_MEDIUM,
|
|
session_id = nothing,
|
|
on_payload = nothing,
|
|
on_response = nothing,
|
|
transport = "auto",
|
|
thinking_budgets = nothing,
|
|
max_retry_delay_ms = nothing,
|
|
tool_execution = EXECUTION_PARALLEL,
|
|
before_tool_call = myBeforeToolCallHook,
|
|
after_tool_call = myAfterToolCallHook,
|
|
prepare_next_turn = myPrepareNextTurnHook,
|
|
convert_to_llm = myConvertToLlm,
|
|
transform_context = myTransformContext,
|
|
get_api_key = myGetApiKey,
|
|
get_steering_messages = myGetSteeringMessages,
|
|
get_follow_up_messages = myGetFollowUpMessages,
|
|
should_stop_after_turn = myShouldStopHook, # Default: always return false
|
|
max_tokens = nothing,
|
|
temperature = nothing,
|
|
cache_retention = nothing,
|
|
headers = nothing,
|
|
metadata = nothing,
|
|
signal = nothing,
|
|
api_key = nothing,
|
|
)
|
|
|
|
# Start agent loop
|
|
stream = agentLoop(
|
|
[UserMessage("user", [TextContent("Hello")], timestamp)],
|
|
AgentContext(system_prompt, messages, tools),
|
|
config,
|
|
nothing,
|
|
stream_fn,
|
|
)
|
|
|
|
# Consume events
|
|
final_messages = []
|
|
for event in stream
|
|
if event isa MessageEndEvent
|
|
push!(final_messages, event.message)
|
|
end
|
|
end
|
|
|
|
# Or use event sink
|
|
messages = []
|
|
emit(event) = push!(messages, event)
|
|
|
|
messages = runAgentLoop(
|
|
[UserMessage(...)],
|
|
context,
|
|
config,
|
|
emit,
|
|
nothing,
|
|
stream_fn,
|
|
)
|
|
```
|
|
|
|
This documentation provides a comprehensive understanding of the AgentLoop component, including its architecture, main functions, execution modes, and best practices for building AI agents with AgentCore.jl.
|