mirror of
https://github.com/langchain-ai/langgraph.git
synced 2026-10-14 12:15:25 +02:00
Baihao WangandGitHub
5965d72ff7
**Problem.** `interrupt(response_schema=...)` checks a human's answer when the graph resumes. If the answer doesn't match the schema, the resume fails, nothing is saved, and the human can answer again (#8886). That works when the interrupt runs in a graph node, but not when it runs inside a tool: either the tool calls `interrupt()` itself, or it starts a graph that does, such as a subagent called as a tool. There, the resume returns normally and the interrupt disappears. **Why.** `interrupt()` raises a `pydantic.ValidationError` for an invalid answer. When one comes out of a tool, `ToolNode` assumes the model passed bad arguments, so it hands the error to the model ("Error invoking tool … Please fix the error and try again") and the run carries on. The human never sees the error, the model is blamed for it, and the interrupt is no longer pending. **Fix.** `interrupt()` still raises the same `ValidationError`, but marks it so a new helper, `langgraph.errors.is_invalid_resume(error)`, can recognize it. `ToolNode` re-raises these errors instead of handing them to the model, whatever `handle_tool_errors` is set to, so a bad answer fails the resume the same way inside a tool as outside one: nothing is saved and the interrupt can be answered again. Every other `ValidationError` from a tool is handled as before. **Also fixed, in the same error handling.** With `wrap_tool_call` set and a `handle_tool_errors` other than the default (for example `True`), `ToolNode` turned any exception from the wrapper into an error `ToolMessage`, including `GraphInterrupt`. So an interrupt in that setup never paused: the model got `Error: GraphInterrupt(...)` instead. Interrupts now propagate there too, as they already do without a wrapper. `create_agent` uses the default handler, so it was not affected. **Compatibility.** Not a breaking change: the error type is unchanged. Worth a careful look: a wrapped `ToolNode` with a non-default `handle_tool_errors` now pauses on interrupts instead of returning them to the model as errors. With an older `langgraph` that doesn't have `is_invalid_resume`, `ToolNode` keeps today's behavior.