welt-io 0.1.0

Agent-side adapters for Welt's wire contract

welt-io

Agent-side adapters for Welt's wire contract.

The wire between Welt and your agent is JSON, and plain Strands values do not fit it in either direction:

• Inbound, JSON cannot carry raw bytes, so Welt base64-encodes the bytes slot of the Converse image/document/video blocks it builds from Slack uploads. decode_file_blocks restores them before Strands (Bedrock Converse) sees the messages; without uploads it is a no-op.
• Outbound, raw stream_async events carry values that are not JSON-serializable (the Agent itself, UUIDs, traces), which the AgentCore Runtime SDK would degrade to a plain string on the SSE wire. renderable_events reduces the stream to the events Welt renders: text chunks (data), tool-use starts (current_tool_use), and tool completions (tool_result, slimmed to the toolUseId and status so tool output stays off the wire).

Install

uv add welt-io

Usage

from collections.abc import AsyncIterator

from bedrock_agentcore.runtime import BedrockAgentCoreApp
from strands import Agent
from welt_io import decode_file_blocks, renderable_events

app = BedrockAgentCoreApp()


@app.entrypoint
async def invoke(payload: dict) -> AsyncIterator[dict]:
    messages = payload["messages"]
    decode_file_blocks(messages)  # base64 file bytes -> raw bytes, in place
    agent = Agent()
    # Reduce the stream to the JSON-serializable events Welt renders
    async for event in renderable_events(agent.stream_async(messages)):
        yield event


if __name__ == "__main__":
    app.run()

License

MIT