What causes "missing `cards` for op=replace" in tinyhumansai/openhuman?

Include "cards" as a JSON array of card objects for op=replace

missing `cards` for op=replace

Error message

missing `cards` for op=replace

What it means

The `todo` tool dispatched op=replace but args has no `cards` key (todo.rs:156). replace swaps the entire board for the provided card list, so cards is mandatory for that op — clearing the board is a separate op=clear, not an empty replace.

Source

Thrown at src/openhuman/agent/tools/todo.rs:156

                let id = required_string(&args, "id")?;
                let mut patch = patch_from_args(&args)?;
                patch.content = optional_string(&args, "content");
                ops::edit(&location, &id, patch).await
            }
            "update_status" => {
                let id = required_string(&args, "id")?;
                let status = required_string(&args, "status")?;
                let status = ops::parse_status(&status).map_err(anyhow::Error::msg)?;
                ops::update_status(&location, &id, status).await
            }
            "remove" => {
                let id = required_string(&args, "id")?;
                ops::remove(&location, &id).await
            }
            "replace" => {
                let cards = args
                    .get("cards")
                    .ok_or_else(|| anyhow::anyhow!("missing `cards` for op=replace"))?;
                let cards: Vec<TaskBoardCard> = serde_json::from_value(cards.clone())
                    .map_err(|e| anyhow::anyhow!("invalid `cards`: {e}"))?;
                ops::replace(&location, cards).await
            }
            "clear" => ops::clear(&location).await,
            "list" => ops::list(&location).await,
            other => {
                return Ok(ToolResult::error(format!(
                "unknown op '{other}' (expected add|edit|update_status|remove|replace|clear|list)"
            )))
            }
        };

        match result {
            Ok(snap) => {
                let payload = json!({
                    "threadId": snap.thread_id,
                    "cards": snap.cards,

View on GitHub (pinned to a221052e0d)

Solutions

Include "cards" as a JSON array of card objects for op=replace
Use op=clear when the intent is an empty board
Validate that op=replace calls carry an array cards field before dispatch

Example fix

// before
{ "op": "replace" }

// after
{ "op": "replace", "cards": [{ "id": "t1", "content": "Ship the fix" }] }

Defensive patterns

Strategy: validation

Validate before calling

const a = args as Record<string, unknown>;
if (a?.op === "replace" && !Array.isArray(a.cards)) {
  throw new Error("todo replace: 'cards' array is required (use op=clear to empty the board)");
}

Type guard

function isReplaceArgs(a: unknown): a is { op: "replace"; cards: unknown[] } {
  const v = a as Record<string, unknown>;
  return v?.op === "replace" && Array.isArray(v.cards);
}

Try / catch

if e.to_string().contains("missing `cards` for op=replace") {
    return Ok(ToolResult::error("replace needs the full 'cards' array; use op=clear for an empty board"));
}

Prevention

Remember replace carries the complete board, clear empties it
Validate replace calls carry an array cards field in wrappers
When syncing board state, build the cards array before choosing replace

When it happens

Trigger: Model sends { "op": "replace" } with no cards; wrapper mapping a board update to replace without including the new card array; intending to clear but choosing the wrong op.

Common situations: Board-sync logic that falls back to replace without a payload; models conflating replace and clear.

Related errors

AI-assisted analysis of tinyhumansai/openhuman@a221052e0d (2026-08-16). Data as JSON: /api/errors/9ad79b00ba779ccc. Report an issue: GitHub.