feat: implement Trello card management

Add 12 card management tools:
- trello_create_card — create a card on a list
- trello_card_details — view card with members, checklists, comments
- trello_update_card — update title, description, due date
- trello_move_card — move card to a different list
- trello_archive_card — archive a card
- trello_assign_member / trello_remove_member — member management
- trello_add_comment / trello_delete_comment — comments
- trello_add_checklist_item / trello_toggle_checklist_item / trello_delete_checklist_item

Also adds _delete() helper on TrelloClient for DELETE verbs.

73 total tests — all passing.

Issue: #4

docs/backend/manage-boards-spec.md

@@ -3,7 +3,6 @@
 **Feature:** US: Manage Trello Boards
 **Issue:** #2
 **Branch:** `feature/manage-boards`
-**Doc:** 002
 
 ## Overview
 

docs/backend/manage-cards-spec.md

@@ -0,0 +1,162 @@
+# Trello Plugin — Manage Trello Cards
+
+**Feature:** US: Manage Trello Cards
+**Issue:** #4
+**Branch:** `feature/manage-cards`
+
+## Overview
+
+Extends the Trello plugin with full card management capabilities: create, view, update, move, archive, assign members, comments, and checklist management.
+
+## Tools
+
+### `trello_create_card`
+Create a new card on a selected list.
+
+**Parameters:**
+| Param | Type | Required | Description |
+|-------|------|----------|-------------|
+| `name` | string | Yes | Card title |
+| `list_id` | string | Yes | List ID |
+| `desc` | string | No | Card description |
+| `due` | string | No | Due date (ISO 8601) |
+
+**Returns:** Card ID, name, URL, and short URL.
+
+### `trello_card_details`
+View detailed information about a card.
+
+**Parameters:**
+| Param | Type | Required | Description |
+|-------|------|----------|-------------|
+| `card_id` | string | Yes | Card ID |
+
+**Returns:** Card details including title, description, due date, members, checklists, comments, URL.
+
+### `trello_update_card`
+Update a card's core attributes (title, description, due date).
+
+**Parameters:**
+| Param | Type | Required | Description |
+|-------|------|----------|-------------|
+| `card_id` | string | Yes | Card ID |
+| `name` | string | No | New title |
+| `desc` | string | No | New description |
+| `due` | string | No | New due date (ISO 8601) |
+
+**Returns:** Updated card details.
+
+### `trello_move_card`
+Move a card to a different list.
+
+**Parameters:**
+| Param | Type | Required | Description |
+|-------|------|----------|-------------|
+| `card_id` | string | Yes | Card ID |
+| `list_id` | string | Yes | Target list ID |
+
+**Returns:** Success message with new list location.
+
+### `trello_archive_card`
+Archive a card.
+
+**Parameters:**
+| Param | Type | Required | Description |
+|-------|------|----------|-------------|
+| `card_id` | string | Yes | Card ID |
+
+**Returns:** Success message.
+
+### `trello_assign_member`
+Add a member to a card.
+
+**Parameters:**
+| Param | Type | Required | Description |
+|-------|------|----------|-------------|
+| `card_id` | string | Yes | Card ID |
+| `member_id` | string | Yes | Trello member ID |
+
+**Returns:** Success message.
+
+### `trello_remove_member`
+Remove a member from a card.
+
+**Parameters:**
+| Param | Type | Required | Description |
+|-------|------|----------|-------------|
+| `card_id` | string | Yes | Card ID |
+| `member_id` | string | Yes | Trello member ID |
+
+**Returns:** Success message.
+
+### `trello_add_comment`
+Add a comment to a card.
+
+**Parameters:**
+| Param | Type | Required | Description |
+|-------|------|----------|-------------|
+| `card_id` | string | Yes | Card ID |
+| `text` | string | Yes | Comment text |
+
+**Returns:** Comment ID and success.
+
+### `trello_delete_comment`
+Delete a comment from a card.
+
+**Parameters:**
+| Param | Type | Required | Description |
+|-------|------|----------|-------------|
+| `card_id` | string | Yes | Card ID |
+| `comment_id` | string | Yes | Comment/action ID |
+
+**Returns:** Success message.
+
+### `trello_add_checklist_item`
+Add a checklist item to a card.
+
+**Parameters:**
+| Param | Type | Required | Description |
+|-------|------|----------|-------------|
+| `card_id` | string | Yes | Card ID |
+| `name` | string | Yes | Checklist item text |
+| `checklist_id` | string | No | Specific checklist ID (if card has multiple) |
+
+**Returns:** Checklist item details.
+
+### `trello_toggle_checklist_item`
+Mark a checklist item as complete or incomplete.
+
+**Parameters:**
+| Param | Type | Required | Description |
+|-------|------|----------|-------------|
+| `card_id` | string | Yes | Card ID |
+| `item_id` | string | Yes | Checklist item ID |
+| `checked` | bool | Yes | True = complete, False = incomplete |
+
+**Returns:** Updated item state.
+
+### `trello_delete_checklist_item`
+Remove a checklist item.
+
+**Parameters:**
+| Param | Type | Required | Description |
+|-------|------|----------|-------------|
+| `card_id` | string | Yes | Card ID |
+| `item_id` | string | Yes | Checklist item ID |
+
+**Returns:** Success message.
+
+## Trello API Endpoints
+
+| Purpose | Method | Endpoint |
+|---------|--------|----------|
+| Create card | POST | `/1/cards` |
+| Get card | GET | `/1/cards/{id}` |
+| Update card | PUT | `/1/cards/{id}` |
+| Add member | POST | `/1/cards/{id}/idMembers` |
+| Remove member | DELETE | `/1/cards/{id}/idMembers/{memberId}` |
+| Add comment | POST | `/1/cards/{id}/actions/comments` |
+| Delete comment | DELETE | `/1/cards/{id}/actions/{commentId}/comments` |
+| Add checklist item | POST | `/1/cards/{id}/checklistItems` |
+| Update checklist item | PUT | `/1/cards/{id}/checklistItem/{itemId}/state` |
+| Delete checklist item | DELETE | `/1/cards/{id}/checklistItems/{itemId}`

docs/backend/manage-lists-spec.md

@@ -3,7 +3,6 @@
 **Feature:** US: Manage Trello Lists
 **Issue:** #3
 **Branch:** `feature/manage-lists`
-**Doc:** 003
 
 ## Overview
 

docs/backend/trello-auth-spec.md

@@ -3,7 +3,6 @@
 **Feature:** US: Authenticate and Connect to Trello Account
 **Issue:** #1
 **Branch:** `feature/trello-auth`
-**Doc:** 001
 
 ## Overview
 

src/trello_plugin/__init__.py

@@ -8,17 +8,29 @@ from trello_plugin.tools import (
     PLUGIN_TOOLS,
     PLUGIN_VERSION,
     check_requirements,
+    trello_add_checklist_item,
+    trello_add_comment,
     trello_archive_board,
+    trello_archive_card,
     trello_archive_list,
+    trello_assign_member,
     trello_board_details,
+    trello_card_details,
     trello_create_board,
+    trello_create_card,
     trello_create_list,
+    trello_delete_checklist_item,
+    trello_delete_comment,
     trello_disconnect,
     trello_list_boards,
+    trello_move_card,
     trello_move_list,
     trello_open_board,
+    trello_remove_member,
     trello_rename_board,
     trello_rename_list,
+    trello_toggle_checklist_item,
+    trello_update_card,
     trello_verify_credentials,
 )
 
@@ -40,4 +52,16 @@ __all__ = [
     "trello_rename_list",
     "trello_archive_list",
     "trello_move_list",
+    "trello_create_card",
+    "trello_card_details",
+    "trello_update_card",
+    "trello_move_card",
+    "trello_archive_card",
+    "trello_assign_member",
+    "trello_remove_member",
+    "trello_add_comment",
+    "trello_delete_comment",
+    "trello_add_checklist_item",
+    "trello_toggle_checklist_item",
+    "trello_delete_checklist_item",
 ]

src/trello_plugin/client.py

@@ -163,6 +163,10 @@ class TrelloClient:
         """Make an authenticated PUT request."""
         return self._request("PUT", path, json_body=json_body)
 
+    def _delete(self, path: str) -> ApiResponse:
+        """Make an authenticated DELETE request."""
+        return self._request("DELETE", path)
+
     # ------------------------------------------------------------------
     # Public API — Auth & Connection
     # ------------------------------------------------------------------
@@ -571,6 +575,398 @@ class TrelloClient:
             "message": result.get("message", "Failed to move list."),
         }
 
+    # ------------------------------------------------------------------
+    # Public API — Card Management
+    # ------------------------------------------------------------------
+
+    def create_card(
+        self,
+        name: str,
+        list_id: str,
+        desc: str = "",
+        due: str | None = None,
+    ) -> dict[str, Any]:
+        """Create a new card on a Trello list.
+
+        Args:
+            name: Card title.
+            list_id: Trello list ID.
+            desc: Card description.
+            due: Due date in ISO 8601 format.
+
+        Returns:
+            dict with card details on success.
+        """
+        body: dict[str, Any] = {"name": name, "idList": list_id}
+        if desc:
+            body["desc"] = desc
+        if due:
+            body["due"] = due
+
+        result = self._post("/cards", json_body=body)
+        if _is_success(result):
+            card = result["data"]
+            return {
+                "success": True,
+                "card": {
+                    "id": card.get("id"),
+                    "name": card.get("name"),
+                    "url": card.get("url"),
+                    "short_url": card.get("shortUrl"),
+                    "id_list": card.get("idList"),
+                },
+            }
+        return {
+            "success": False,
+            "message": result.get("message", "Failed to create card."),
+        }
+
+    def card_details(self, card_id: str) -> dict[str, Any]:
+        """Fetch detailed information about a card.
+
+        Returns card attributes, members, checklists, and comments.
+
+        Args:
+            card_id: Trello card ID.
+
+        Returns:
+            dict with full card details.
+        """
+        result = self._get(
+            f"/cards/{card_id}",
+            params={
+                "fields": "id,name,desc,due,dueComplete,url,shortUrl,idList,closed",
+                "members": "true",
+                "member_fields": "id,username,fullName",
+                "checklists": "all",
+                "actions": "commentCard",
+                "actions_limit": "50",
+                "list": "true",
+            },
+        )
+        if not _is_success(result):
+            return {
+                "success": False,
+                "message": result.get("message", "Failed to fetch card details."),
+            }
+
+        card = result["data"]
+        return {
+            "success": True,
+            "card": {
+                "id": card.get("id"),
+                "name": card.get("name"),
+                "desc": card.get("desc", ""),
+                "due": card.get("due"),
+                "due_complete": card.get("dueComplete", False),
+                "url": card.get("url"),
+                "short_url": card.get("shortUrl"),
+                "closed": card.get("closed", False),
+                "list": {"id": card.get("idList"), "name": (card.get("list") or {}).get("name", "")},
+                "members": [
+                    {"id": m.get("id"), "username": m.get("username"), "full_name": m.get("fullName")}
+                    for m in card.get("members", [])
+                ],
+                "checklists": [
+                    {
+                        "id": cl.get("id"),
+                        "name": cl.get("name"),
+                        "items": [
+                            {
+                                "id": item.get("id"),
+                                "name": item.get("name"),
+                                "state": item.get("state"),
+                            }
+                            for item in cl.get("checkItems", [])
+                        ],
+                    }
+                    for cl in card.get("checklists", [])
+                ],
+                "comments": [
+                    {
+                        "id": a.get("id"),
+                        "text": a.get("data", {}).get("text", ""),
+                        "member": a.get("memberCreator", {}).get("username", "unknown"),
+                        "date": a.get("date"),
+                    }
+                    for a in card.get("actions", [])
+                    if a.get("type") == "commentCard"
+                ],
+            },
+        }
+
+    def update_card(
+        self,
+        card_id: str,
+        name: str | None = None,
+        desc: str | None = None,
+        due: str | None = None,
+    ) -> dict[str, Any]:
+        """Update a card's core attributes.
+
+        Args:
+            card_id: Trello card ID.
+            name: New title (omit to keep current).
+            desc: New description (omit to keep current).
+            due: New due date ISO 8601, or empty string to clear.
+
+        Returns:
+            dict with updated card details.
+        """
+        body: dict[str, Any] = {}
+        if name is not None:
+            body["name"] = name
+        if desc is not None:
+            body["desc"] = desc
+        if due is not None:
+            body["due"] = due
+
+        if not body:
+            return {
+                "success": True,
+                "message": "No changes specified.",
+            }
+
+        result = self._put(f"/cards/{card_id}", json_body=body)
+        if _is_success(result):
+            card = result["data"]
+            return {
+                "success": True,
+                "card": {
+                    "id": card.get("id"),
+                    "name": card.get("name"),
+                    "desc": card.get("desc", ""),
+                    "due": card.get("due"),
+                },
+            }
+        return {
+            "success": False,
+            "message": result.get("message", "Failed to update card."),
+        }
+
+    def move_card(self, card_id: str, list_id: str) -> dict[str, Any]:
+        """Move a card to a different list.
+
+        Args:
+            card_id: Trello card ID.
+            list_id: Target list ID.
+
+        Returns:
+            dict with success message.
+        """
+        result = self._put(f"/cards/{card_id}", json_body={"idList": list_id})
+        if _is_success(result):
+            card = result["data"]
+            return {
+                "success": True,
+                "message": f"Card '{card.get('name', card_id)}' moved to list '{card.get('idList', list_id)}'.",
+            }
+        return {
+            "success": False,
+            "message": result.get("message", "Failed to move card."),
+        }
+
+    def archive_card(self, card_id: str) -> dict[str, Any]:
+        """Archive a card.
+
+        Args:
+            card_id: Trello card ID.
+
+        Returns:
+            dict with success message.
+        """
+        result = self._put(f"/cards/{card_id}", json_body={"closed": True})
+        if _is_success(result):
+            card = result["data"]
+            return {"success": True, "message": f"Card '{card.get('name', card_id)}' archived."}
+        return {
+            "success": False,
+            "message": result.get("message", "Failed to archive card."),
+        }
+
+    def assign_member(self, card_id: str, member_id: str) -> dict[str, Any]:
+        """Add a member to a card.
+
+        Args:
+            card_id: Trello card ID.
+            member_id: Trello member ID.
+
+        Returns:
+            dict with success message.
+        """
+        result = self._post(f"/cards/{card_id}/idMembers", json_body={"value": member_id})
+        if _is_success(result):
+            return {"success": True, "message": f"Member {member_id} assigned to card."}
+        return {
+            "success": False,
+            "message": result.get("message", "Failed to assign member."),
+        }
+
+    def remove_member(self, card_id: str, member_id: str) -> dict[str, Any]:
+        """Remove a member from a card.
+
+        Args:
+            card_id: Trello card ID.
+            member_id: Trello member ID.
+
+        Returns:
+            dict with success message.
+        """
+        result = self._delete(f"/cards/{card_id}/idMembers/{member_id}")
+        if _is_success(result):
+            return {"success": True, "message": f"Member {member_id} removed from card."}
+        return {
+            "success": False,
+            "message": result.get("message", "Failed to remove member."),
+        }
+
+    def add_comment(self, card_id: str, text: str) -> dict[str, Any]:
+        """Add a comment to a card.
+
+        Args:
+            card_id: Trello card ID.
+            text: Comment text.
+
+        Returns:
+            dict with comment details.
+        """
+        result = self._post(
+            f"/cards/{card_id}/actions/comments",
+            json_body={"text": text},
+        )
+        if _is_success(result):
+            action = result["data"]
+            return {
+                "success": True,
+                "comment": {
+                    "id": action.get("id"),
+                    "text": action.get("data", {}).get("text", text),
+                },
+            }
+        return {
+            "success": False,
+            "message": result.get("message", "Failed to add comment."),
+        }
+
+    def delete_comment(self, card_id: str, comment_id: str) -> dict[str, Any]:
+        """Delete a comment from a card.
+
+        Args:
+            card_id: Trello card ID.
+            comment_id: Action/comment ID.
+
+        Returns:
+            dict with success message.
+        """
+        result = self._delete(f"/cards/{card_id}/actions/{comment_id}/comments")
+        if _is_success(result):
+            return {"success": True, "message": "Comment deleted."}
+        return {
+            "success": False,
+            "message": result.get("message", "Failed to delete comment."),
+        }
+
+    def add_checklist_item(self, card_id: str, name: str, checklist_id: str | None = None) -> dict[str, Any]:
+        """Add a checklist item to a card.
+
+        Args:
+            card_id: Trello card ID.
+            name: Checklist item text.
+            checklist_id: Specific checklist (fetches first if omitted).
+
+        Returns:
+            dict with item details.
+        """
+        resolved_checklist_id = checklist_id
+        if not resolved_checklist_id:
+            # Fetch checklists to find the first one
+            details = self.card_details(card_id)
+            if not details.get("success"):
+                return {
+                    "success": False,
+                    "message": "Card has no checklists. Add one via Trello web first.",
+                }
+            checklists = details["card"].get("checklists", [])
+            if not checklists:
+                return {
+                    "success": False,
+                    "message": "Card has no checklists. Add one via Trello web first.",
+                }
+            resolved_checklist_id = checklists[0]["id"]
+
+        result = self._post(
+            f"/cards/{card_id}/checklistItems",
+            json_body={
+                "idChecklist": resolved_checklist_id,
+                "name": name,
+                "checked": False,
+            },
+        )
+        if _is_success(result):
+            item = result["data"]
+            return {
+                "success": True,
+                "item": {
+                    "id": item.get("id"),
+                    "name": item.get("name"),
+                    "state": item.get("state", "incomplete"),
+                    "id_checklist": item.get("idChecklist"),
+                },
+            }
+        return {
+            "success": False,
+            "message": result.get("message", "Failed to add checklist item."),
+        }
+
+    def toggle_checklist_item(self, card_id: str, item_id: str, checked: bool) -> dict[str, Any]:  # noqa: FBT001
+        """Mark a checklist item as complete or incomplete.
+
+        Args:
+            card_id: Trello card ID.
+            item_id: Checklist item ID.
+            checked: True for complete, False for incomplete.
+
+        Returns:
+            dict with updated item state.
+        """
+        state = "complete" if checked else "incomplete"
+        result = self._put(
+            f"/cards/{card_id}/checklistItem/{item_id}",
+            json_body={"state": state},
+        )
+        if _is_success(result):
+            item = result["data"]
+            return {
+                "success": True,
+                "item": {
+                    "id": item.get("id"),
+                    "name": item.get("name"),
+                    "state": item.get("state"),
+                },
+            }
+        return {
+            "success": False,
+            "message": result.get("message", "Failed to update checklist item."),
+        }
+
+    def delete_checklist_item(self, card_id: str, item_id: str) -> dict[str, Any]:
+        """Remove a checklist item.
+
+        Args:
+            card_id: Trello card ID.
+            item_id: Checklist item ID.
+
+        Returns:
+            dict with success message.
+        """
+        result = self._delete(f"/cards/{card_id}/checklistItems/{item_id}")
+        if _is_success(result):
+            return {"success": True, "message": "Checklist item deleted."}
+        return {
+            "success": False,
+            "message": result.get("message", "Failed to delete checklist item."),
+        }
+
     @staticmethod
     def check_requirements() -> bool:
         """Check if the required environment variables are set."""

src/trello_plugin/tools.py

@@ -260,6 +260,259 @@ def trello_move_list(list_id: str, pos: str = "bottom") -> str:
     return _respond(result)
 
 
+# ---------------------------------------------------------------------------
+# Tools — Card Management
+# ---------------------------------------------------------------------------
+
+
+def trello_create_card(name: str, list_id: str, desc: str = "", due: str | None = None) -> str:
+    """Create a new card on a Trello list.
+
+    Parameters
+    ----------
+    name : str
+        Card title.
+    list_id : str
+        List ID.
+    desc : str, optional
+        Card description.
+    due : str, optional
+        Due date in ISO 8601 format.
+
+    Returns
+    -------
+    str
+        JSON with card details.
+    """
+    client = _get_client()
+    result = client.create_card(name=name, list_id=list_id, desc=desc, due=due)
+    return _respond(result)
+
+
+def trello_card_details(card_id: str) -> str:
+    """View detailed information about a Trello card.
+
+    Parameters
+    ----------
+    card_id : str
+        Card ID.
+
+    Returns
+    -------
+    str
+        JSON with full card details including members, checklists, and comments.
+    """
+    client = _get_client()
+    result = client.card_details(card_id=card_id)
+    return _respond(result)
+
+
+def trello_update_card(card_id: str, name: str | None = None, desc: str | None = None, due: str | None = None) -> str:
+    """Update a card's core attributes (title, description, due date).
+
+    Parameters
+    ----------
+    card_id : str
+        Card ID.
+    name : str, optional
+        New title.
+    desc : str, optional
+        New description.
+    due : str, optional
+        New due date ISO 8601.
+
+    Returns
+    -------
+    str
+        JSON with updated card details.
+    """
+    client = _get_client()
+    result = client.update_card(card_id=card_id, name=name, desc=desc, due=due)
+    return _respond(result)
+
+
+def trello_move_card(card_id: str, list_id: str) -> str:
+    """Move a card to a different list.
+
+    Parameters
+    ----------
+    card_id : str
+        Card ID.
+    list_id : str
+        Target list ID.
+
+    Returns
+    -------
+    str
+        JSON with success message.
+    """
+    client = _get_client()
+    result = client.move_card(card_id=card_id, list_id=list_id)
+    return _respond(result)
+
+
+def trello_archive_card(card_id: str) -> str:
+    """Archive a Trello card.
+
+    Parameters
+    ----------
+    card_id : str
+        Card ID.
+
+    Returns
+    -------
+    str
+        JSON with success message.
+    """
+    client = _get_client()
+    result = client.archive_card(card_id=card_id)
+    return _respond(result)
+
+
+def trello_assign_member(card_id: str, member_id: str) -> str:
+    """Add a member to a Trello card.
+
+    Parameters
+    ----------
+    card_id : str
+        Card ID.
+    member_id : str
+        Trello member ID.
+
+    Returns
+    -------
+    str
+        JSON with success message.
+    """
+    client = _get_client()
+    result = client.assign_member(card_id=card_id, member_id=member_id)
+    return _respond(result)
+
+
+def trello_remove_member(card_id: str, member_id: str) -> str:
+    """Remove a member from a Trello card.
+
+    Parameters
+    ----------
+    card_id : str
+        Card ID.
+    member_id : str
+        Trello member ID.
+
+    Returns
+    -------
+    str
+        JSON with success message.
+    """
+    client = _get_client()
+    result = client.remove_member(card_id=card_id, member_id=member_id)
+    return _respond(result)
+
+
+def trello_add_comment(card_id: str, text: str) -> str:
+    """Add a comment to a Trello card.
+
+    Parameters
+    ----------
+    card_id : str
+        Card ID.
+    text : str
+        Comment text.
+
+    Returns
+    -------
+    str
+        JSON with comment ID.
+    """
+    client = _get_client()
+    result = client.add_comment(card_id=card_id, text=text)
+    return _respond(result)
+
+
+def trello_delete_comment(card_id: str, comment_id: str) -> str:
+    """Delete a comment from a Trello card.
+
+    Parameters
+    ----------
+    card_id : str
+        Card ID.
+    comment_id : str
+        Comment/action ID.
+
+    Returns
+    -------
+    str
+        JSON with success message.
+    """
+    client = _get_client()
+    result = client.delete_comment(card_id=card_id, comment_id=comment_id)
+    return _respond(result)
+
+
+def trello_add_checklist_item(card_id: str, name: str, checklist_id: str | None = None) -> str:
+    """Add a checklist item to a Trello card.
+
+    Parameters
+    ----------
+    card_id : str
+        Card ID.
+    name : str
+        Checklist item text.
+    checklist_id : str, optional
+        Specific checklist ID (auto-discovers the first if omitted).
+
+    Returns
+    -------
+    str
+        JSON with item details.
+    """
+    client = _get_client()
+    result = client.add_checklist_item(card_id=card_id, name=name, checklist_id=checklist_id)
+    return _respond(result)
+
+
+def trello_toggle_checklist_item(card_id: str, item_id: str, checked: bool) -> str:  # noqa: FBT001
+    """Mark a checklist item as complete or incomplete.
+
+    Parameters
+    ----------
+    card_id : str
+        Card ID.
+    item_id : str
+        Checklist item ID.
+    checked : bool
+        True = complete, False = incomplete.
+
+    Returns
+    -------
+    str
+        JSON with updated item state.
+    """
+    client = _get_client()
+    result = client.toggle_checklist_item(card_id=card_id, item_id=item_id, checked=checked)
+    return _respond(result)
+
+
+def trello_delete_checklist_item(card_id: str, item_id: str) -> str:
+    """Remove a checklist item from a Trello card.
+
+    Parameters
+    ----------
+    card_id : str
+        Card ID.
+    item_id : str
+        Checklist item ID.
+
+    Returns
+    -------
+    str
+        JSON with success message.
+    """
+    client = _get_client()
+    result = client.delete_checklist_item(card_id=card_id, item_id=item_id)
+    return _respond(result)
+
+
 # ---------------------------------------------------------------------------
 # Plugin metadata (used by Hermes plugin loader)
 # ---------------------------------------------------------------------------
@@ -280,6 +533,18 @@ PLUGIN_TOOLS = [
     trello_rename_list,
     trello_archive_list,
     trello_move_list,
+    trello_create_card,
+    trello_card_details,
+    trello_update_card,
+    trello_move_card,
+    trello_archive_card,
+    trello_assign_member,
+    trello_remove_member,
+    trello_add_comment,
+    trello_delete_comment,
+    trello_add_checklist_item,
+    trello_toggle_checklist_item,
+    trello_delete_checklist_item,
 ]
 PLUGIN_REQUIRES_ENV = ["TRELLO_API_KEY", "TRELLO_TOKEN"]
 

tests/test_auth.py

@@ -325,5 +325,5 @@ class TestPluginMetadata:
         assert PLUGIN_NAME == "trello-plugin"
         assert isinstance(PLUGIN_DESCRIPTION, str)
         assert isinstance(PLUGIN_VERSION, str)
-        assert len(PLUGIN_TOOLS) == 12
+        assert len(PLUGIN_TOOLS) == 24
         assert all(callable(t) for t in PLUGIN_TOOLS)

tests/test_cards.py

@@ -0,0 +1,313 @@
+"""Tests for the Trello plugin — card management feature."""
+
+from __future__ import annotations
+
+import json
+import os
+from typing import Any
+
+import pytest
+
+pytestmark = pytest.mark.usefixtures("clear_env")
+
+
+@pytest.fixture(autouse=True)
+def clear_env(monkeypatch: pytest.MonkeyPatch) -> Any:
+    monkeypatch.delenv("TRELLO_API_KEY", raising=False)
+    monkeypatch.delenv("TRELLO_TOKEN", raising=False)
+
+
+# ---------------------------------------------------------------------------
+# TrelloClient — create_card
+# ---------------------------------------------------------------------------
+
+class TestCreateCard:
+    def test_success(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.post("https://api.trello.com/1/cards", json={"id": "c1", "name": "My Card", "url": "https://trello.com/c/c1", "shortUrl": "https://trello.com/c/abc", "idList": "l1"})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.create_card(name="My Card", list_id="l1")
+        assert result["success"]
+        assert result["card"]["name"] == "My Card"
+
+    def test_with_description_and_due(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.post("https://api.trello.com/1/cards", json={"id": "c1", "name": "Card", "url": "", "shortUrl": "", "idList": "l1"})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.create_card(name="Card", list_id="l1", desc="Desc", due="2026-06-01T00:00:00Z")
+        assert result["success"]
+
+    def test_missing_credentials(self) -> None:
+        from trello_plugin.client import TrelloClient
+        client = TrelloClient(api_key="", token="")
+        result = client.create_card(name="Card", list_id="l1")
+        assert not result["success"]
+        assert "TRELLO_API_KEY" in result["message"]
+
+
+# ---------------------------------------------------------------------------
+# TrelloClient — card_details
+# ---------------------------------------------------------------------------
+
+class TestCardDetails:
+    def test_success(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.get(
+            "https://api.trello.com/1/cards/c1",
+            json={
+                "id": "c1", "name": "My Card", "desc": "Description", "due": None,
+                "dueComplete": False, "url": "https://trello.com/c/c1", "shortUrl": "https://trello.com/c/abc",
+                "idList": "l1", "closed": False, "list": {"id": "l1", "name": "To Do"},
+                "members": [{"id": "m1", "username": "user1", "fullName": "User One"}],
+                "checklists": [{"id": "cl1", "name": "Checklist", "checkItems": [{"id": "ci1", "name": "Item", "state": "incomplete"}]}],
+                "actions": [{"id": "a1", "type": "commentCard", "data": {"text": "Nice card"}, "memberCreator": {"username": "user1"}, "date": "2026-05-01T00:00:00Z"}],
+            },
+        )
+        client = TrelloClient(api_key="k", token="t")
+        result = client.card_details(card_id="c1")
+        assert result["success"]
+        assert result["card"]["name"] == "My Card"
+        assert len(result["card"]["members"]) == 1
+        assert len(result["card"]["checklists"]) == 1
+        assert len(result["card"]["comments"]) == 1
+
+
+# ---------------------------------------------------------------------------
+# TrelloClient — update_card
+# ---------------------------------------------------------------------------
+
+class TestUpdateCard:
+    def test_update_name(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.put("https://api.trello.com/1/cards/c1", json={"id": "c1", "name": "Updated", "desc": "", "due": None})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.update_card(card_id="c1", name="Updated")
+        assert result["success"]
+        assert result["card"]["name"] == "Updated"
+
+    def test_no_changes(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        client = TrelloClient(api_key="k", token="t")
+        result = client.update_card(card_id="c1")
+        assert result["success"]
+        assert "No changes" in result["message"]
+
+
+# ---------------------------------------------------------------------------
+# TrelloClient — move_card, archive_card
+# ---------------------------------------------------------------------------
+
+class TestMoveCard:
+    def test_success(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.put("https://api.trello.com/1/cards/c1", json={"id": "c1", "name": "Card", "idList": "l2"})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.move_card(card_id="c1", list_id="l2")
+        assert result["success"]
+
+
+class TestArchiveCard:
+    def test_success(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.put("https://api.trello.com/1/cards/c1", json={"id": "c1", "name": "Card", "closed": True})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.archive_card(card_id="c1")
+        assert result["success"]
+
+
+# ---------------------------------------------------------------------------
+# TrelloClient — member operations
+# ---------------------------------------------------------------------------
+
+class TestMemberOps:
+    def test_assign_member(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.post("https://api.trello.com/1/cards/c1/idMembers", json={"id": "c1"}, status_code=200)
+        client = TrelloClient(api_key="k", token="t")
+        result = client.assign_member(card_id="c1", member_id="m1")
+        assert result["success"]
+
+    def test_remove_member(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.delete("https://api.trello.com/1/cards/c1/idMembers/m1", status_code=200, json={})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.remove_member(card_id="c1", member_id="m1")
+        assert result["success"]
+
+
+# ---------------------------------------------------------------------------
+# TrelloClient — comments
+# ---------------------------------------------------------------------------
+
+class TestComments:
+    def test_add_comment(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.post("https://api.trello.com/1/cards/c1/actions/comments", json={"id": "a1", "data": {"text": "Great!"}})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.add_comment(card_id="c1", text="Great!")
+        assert result["success"]
+        assert result["comment"]["id"] == "a1"
+
+    def test_delete_comment(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.delete("https://api.trello.com/1/cards/c1/actions/a1/comments", status_code=200, json={})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.delete_comment(card_id="c1", comment_id="a1")
+        assert result["success"]
+
+
+# ---------------------------------------------------------------------------
+# TrelloClient — checklists
+# ---------------------------------------------------------------------------
+
+class TestChecklistItems:
+    def test_add_item_with_checklist_id(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.post("https://api.trello.com/1/cards/c1/checklistItems", json={"id": "ci1", "name": "Task", "state": "incomplete", "idChecklist": "cl1"})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.add_checklist_item(card_id="c1", name="Task", checklist_id="cl1")
+        assert result["success"]
+        assert result["item"]["name"] == "Task"
+
+    def test_add_item_auto_discover(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        # card_details call for auto-discover
+        requests_mock.get(
+            "https://api.trello.com/1/cards/c1",
+            json={
+                "id": "c1", "name": "Card", "desc": "", "due": None,
+                "dueComplete": False, "url": "", "shortUrl": "", "idList": "l1", "closed": False,
+                "list": {"id": "l1", "name": "List"},
+                "members": [], "checklists": [{"id": "cl1", "name": "Checklist", "checkItems": []}],
+                "actions": [],
+            },
+        )
+        requests_mock.post("https://api.trello.com/1/cards/c1/checklistItems", json={"id": "ci1", "name": "Auto", "state": "incomplete", "idChecklist": "cl1"})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.add_checklist_item(card_id="c1", name="Auto")
+        assert result["success"]
+
+    def test_toggle_complete(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.put("https://api.trello.com/1/cards/c1/checklistItem/ci1", json={"id": "ci1", "name": "Task", "state": "complete"})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.toggle_checklist_item(card_id="c1", item_id="ci1", checked=True)
+        assert result["success"]
+        assert result["item"]["state"] == "complete"
+
+    def test_toggle_incomplete(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.put("https://api.trello.com/1/cards/c1/checklistItem/ci1", json={"id": "ci1", "name": "Task", "state": "incomplete"})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.toggle_checklist_item(card_id="c1", item_id="ci1", checked=False)
+        assert result["success"]
+        assert result["item"]["state"] == "incomplete"
+
+    def test_delete_item(self, requests_mock: Any) -> None:
+        from trello_plugin.client import TrelloClient
+        requests_mock.delete("https://api.trello.com/1/cards/c1/checklistItems/ci1", status_code=200, json={})
+        client = TrelloClient(api_key="k", token="t")
+        result = client.delete_checklist_item(card_id="c1", item_id="ci1")
+        assert result["success"]
+
+
+# ---------------------------------------------------------------------------
+# Tool functions
+# ---------------------------------------------------------------------------
+
+class TestCardToolFunctions:
+    def test_trello_create_card_tool(self, requests_mock: Any) -> None:
+        from trello_plugin.tools import trello_create_card
+        os.environ["TRELLO_API_KEY"] = "k"
+        os.environ["TRELLO_TOKEN"] = "t"
+        requests_mock.post("https://api.trello.com/1/cards", json={"id": "c1", "name": "Card", "url": "", "shortUrl": "", "idList": "l1"})
+        result = json.loads(trello_create_card(name="Card", list_id="l1"))
+        assert result["success"]
+
+    def test_trello_card_details_tool(self, requests_mock: Any) -> None:
+        from trello_plugin.tools import trello_card_details
+        os.environ["TRELLO_API_KEY"] = "k"
+        os.environ["TRELLO_TOKEN"] = "t"
+        requests_mock.get("https://api.trello.com/1/cards/c1", json={"id": "c1", "name": "Card", "desc": "", "due": None, "dueComplete": False, "url": "", "shortUrl": "", "idList": "l1", "closed": False, "list": {"id": "l1", "name": "List"}, "members": [], "checklists": [], "actions": []})
+        result = json.loads(trello_card_details(card_id="c1"))
+        assert result["success"]
+
+    def test_trello_update_card_tool(self, requests_mock: Any) -> None:
+        from trello_plugin.tools import trello_update_card
+        os.environ["TRELLO_API_KEY"] = "k"
+        os.environ["TRELLO_TOKEN"] = "t"
+        requests_mock.put("https://api.trello.com/1/cards/c1", json={"id": "c1", "name": "New", "desc": "", "due": None})
+        result = json.loads(trello_update_card(card_id="c1", name="New"))
+        assert result["success"]
+
+    def test_trello_move_card_tool(self, requests_mock: Any) -> None:
+        from trello_plugin.tools import trello_move_card
+        os.environ["TRELLO_API_KEY"] = "k"
+        os.environ["TRELLO_TOKEN"] = "t"
+        requests_mock.put("https://api.trello.com/1/cards/c1", json={"id": "c1", "name": "Card", "idList": "l2"})
+        result = json.loads(trello_move_card(card_id="c1", list_id="l2"))
+        assert result["success"]
+
+    def test_trello_archive_card_tool(self, requests_mock: Any) -> None:
+        from trello_plugin.tools import trello_archive_card
+        os.environ["TRELLO_API_KEY"] = "k"
+        os.environ["TRELLO_TOKEN"] = "t"
+        requests_mock.put("https://api.trello.com/1/cards/c1", json={"id": "c1", "name": "Card", "closed": True})
+        result = json.loads(trello_archive_card(card_id="c1"))
+        assert result["success"]
+
+    def test_trello_assign_member_tool(self, requests_mock: Any) -> None:
+        from trello_plugin.tools import trello_assign_member
+        os.environ["TRELLO_API_KEY"] = "k"
+        os.environ["TRELLO_TOKEN"] = "t"
+        requests_mock.post("https://api.trello.com/1/cards/c1/idMembers", json={}, status_code=200)
+        result = json.loads(trello_assign_member(card_id="c1", member_id="m1"))
+        assert result["success"]
+
+    def test_trello_remove_member_tool(self, requests_mock: Any) -> None:
+        from trello_plugin.tools import trello_remove_member
+        os.environ["TRELLO_API_KEY"] = "k"
+        os.environ["TRELLO_TOKEN"] = "t"
+        requests_mock.delete("https://api.trello.com/1/cards/c1/idMembers/m1", status_code=200, json={})
+        result = json.loads(trello_remove_member(card_id="c1", member_id="m1"))
+        assert result["success"]
+
+    def test_trello_add_comment_tool(self, requests_mock: Any) -> None:
+        from trello_plugin.tools import trello_add_comment
+        os.environ["TRELLO_API_KEY"] = "k"
+        os.environ["TRELLO_TOKEN"] = "t"
+        requests_mock.post("https://api.trello.com/1/cards/c1/actions/comments", json={"id": "a1", "data": {"text": "Nice"}})
+        result = json.loads(trello_add_comment(card_id="c1", text="Nice"))
+        assert result["success"]
+
+    def test_trello_delete_comment_tool(self, requests_mock: Any) -> None:
+        from trello_plugin.tools import trello_delete_comment
+        os.environ["TRELLO_API_KEY"] = "k"
+        os.environ["TRELLO_TOKEN"] = "t"
+        requests_mock.delete("https://api.trello.com/1/cards/c1/actions/a1/comments", status_code=200, json={})
+        result = json.loads(trello_delete_comment(card_id="c1", comment_id="a1"))
+        assert result["success"]
+
+    def test_trello_add_checklist_item_tool(self, requests_mock: Any) -> None:
+        from trello_plugin.tools import trello_add_checklist_item
+        os.environ["TRELLO_API_KEY"] = "k"
+        os.environ["TRELLO_TOKEN"] = "t"
+        requests_mock.post("https://api.trello.com/1/cards/c1/checklistItems", json={"id": "ci1", "name": "Task", "state": "incomplete", "idChecklist": "cl1"})
+        result = json.loads(trello_add_checklist_item(card_id="c1", name="Task", checklist_id="cl1"))
+        assert result["success"]
+
+    def test_trello_toggle_checklist_item_tool(self, requests_mock: Any) -> None:
+        from trello_plugin.tools import trello_toggle_checklist_item
+        os.environ["TRELLO_API_KEY"] = "k"
+        os.environ["TRELLO_TOKEN"] = "t"
+        requests_mock.put("https://api.trello.com/1/cards/c1/checklistItem/ci1", json={"id": "ci1", "name": "Task", "state": "complete"})
+        result = json.loads(trello_toggle_checklist_item(card_id="c1", item_id="ci1", checked=True))
+        assert result["success"]
+
+    def test_trello_delete_checklist_item_tool(self, requests_mock: Any) -> None:
+        from trello_plugin.tools import trello_delete_checklist_item
+        os.environ["TRELLO_API_KEY"] = "k"
+        os.environ["TRELLO_TOKEN"] = "t"
+        requests_mock.delete("https://api.trello.com/1/cards/c1/checklistItems/ci1", status_code=200, json={})
+        result = json.loads(trello_delete_checklist_item(card_id="c1", item_id="ci1"))
+        assert result["success"]