openclaw - 💡(How to fix) Fix pi-agent-core: assistantMessage.content.filter() crash when content is not an array [3 comments, 4 participants]

TypeError: toolMsg.content.filter is not a function

Fix Plan

To fix the issue, we need to ensure that .filter() is only called on message.content and assistantMessage.content if they are arrays.

Here are the steps:

• Identify the two call sites in dist/agent-loop.js where .filter() is called directly on message.content and assistantMessage.content.
• Modify these lines to check if the content is an array before calling .filter().

Example code for the fix:

// Site 1 — Line 112
const toolCalls = (Array.isArray(message.content) ? message.content : []).filter((c) => c.type === "toolCall");

// Site 2 — Line 233
const toolCalls = (Array.isArray(assistantMessage.content) ? assistantMessage.content : []).filter((c) => c.type === "toolCall");

Verification

To verify that the fix worked:

• Spawn a sub-agent via sessions_spawn with runtime: "subagent" and have it return a message where content is a string (not an array).
• Check that the parent agent loop no longer crashes when processing the result.
• Test with different types of content (e.g., array, string, object) to ensure the fix is robust.

Extra Tips

• This fix uses the Array.isArray() method to check if the content is an array, and if not, defaults to an empty array [] to avoid errors.
• This pattern is already used elsewhere in the same file, so it's consistent with existing code.