earendil-works/pi · error · Error

Agent run ended with unexpected stop reason: ${assistant.sto

Error message

Agent run ended with unexpected stop reason: ${assistant.stopReason}.

What it means

Error "Agent run ended with unexpected stop reason: ${assistant.stopReason}." thrown in earendil-works/pi.

Source

Thrown at packages/evals/src/pi-harness.ts:100

				content: message.content.every((part) => part.type === "text") ? text : toJsonValue(message.content),
				...(message.isError ? { error: { message: text || "Tool failed" } } : {}),
			});
		}
	}
	return events;
}

async function promptAgent(session: AgentSession, input: string, signal: AbortSignal | undefined): Promise<string> {
	signal?.throwIfAborted();
	const previousMessageCount = session.messages.length;
	await session.prompt(input);
	const assistant = session.messages
		.slice(previousMessageCount)
		.reverse()
		.find((message) => message.role === "assistant");
	if (!assistant) throw new Error("Agent run completed without an assistant message.");
	if (assistant.stopReason !== "stop") {
		throw new Error(
			assistant.errorMessage ?? `Agent run ended with unexpected stop reason: ${assistant.stopReason}.`,
		);
	}
	const output = session.getLastAssistantText();
	if (!output) throw new Error("Agent run produced no assistant text.");
	return output;
}

async function runPiCodingAgent<TOutput extends JsonValue>(
	input: PiCodingAgentInput,
	signal: AbortSignal | undefined,
	setArtifact: HarnessContext["setArtifact"],
	options: PiCodingAgentHarnessOptions | PiCodingAgentHarnessWithOutput<TOutput>,
): Promise<SimpleHarnessResult<string | TOutput>> {
	const startedAt = performance.now();
	signal?.throwIfAborted();
	const selection = resolveModelSelection(options.model);
	const modelRuntime = await ModelRuntime.create();

View on GitHub (pinned to 4af9d21d3b)

When it happens

Trigger: Thrown at packages/evals/src/pi-harness.ts:100 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of earendil-works/pi@4af9d21d3b (2026-08-24). Data as JSON: /api/errors/d3c44518ed07ad93. Report an issue: GitHub.