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symfonic-core

protocol

symfonic-core on PyPI

`symfonic.core.callbacks.protocol`¶

protocol ¶

CallbackHandler protocol -- user-facing async callback contract.

Scope: agent/node lifecycle and LLM invocation events. Follows the exact pattern of observability/protocol.py (ObservabilityHook).

CallbackHandler ¶

Bases: Protocol

Async callback protocol for agent graph lifecycle events.

Implement this protocol to receive notifications about agent start/end, node start/end/error, LLM invocation events, and token composition breakdowns during graph execution.