MessageLog

this.messages — append-only conversation history with seq ordering and adapters for LangChain, OpenAI, and Anthropic.

this.messages is the agent’s persistent conversation log. Messages are ordered by an assigned monotonic seq (insertion order, not wall-clock), and the log is append-only — there is no delete.

The log is the agent’s memory across turns. Append messages as they happen — user input, assistant replies, tool results — and rebuild the next LLM request from history: last(n) for a bounded window, or an adapter for a provider-shaped payload. Because the log persists with the instance, a crash, a restart, or a week of idleness doesn’t lose the thread. The Message History guide walks the full loop.

Accessing the log

The log hangs off one Agent property:

new MessageLog()

You rarely construct one — this.messages is built for you — but a standalone log over the actor’s storage is a plain constructor call:

AgentMessage

ToolCall

StoredMessage

add()

append()

appendMany()

all()

last()

count()

Adapters

Each adapter reads the full history and converts it. They differ in how they treat system and tool messages:

Adapter	Output	system	tool / toolCalls
toLangChain()	plain { role, content }	included	dropped — only user/assistant/system survive
toOpenAI()	Chat Completions messages	included	mapped to tool_calls / tool_call_id, args JSON-stringified
toAnthropic()	Messages-API turns	dropped — pass the system prompt as the top-level system param	assistant toolCalls become tool_use blocks; tool results become user turns with tool_result blocks

const history = await this.messages.toOpenAI();
// → ready for env.TELNYX.ai.openai.chat.createCompletion({ model, messages: history })
//   (the pre-authenticated binding) or any OpenAI-compatible client

If you record tool calls in history and hand it to LangChain, note the drop: persist what the framework needs via append() with plain roles, or rebuild framework state from toOpenAI() output instead.

toOpenAI()

toAnthropic()

toLangChain()