update_memory_block

Modify the content and metadata of a memory block in the Letta system by specifying its ID, enabling updates to stored information for agent operations.

Instructions

Update the contents and metadata of a memory block. Use list_memory_blocks to find block IDs, or read_memory_block to see current content before updating.

Input Schema

TableJSON Schema

Name	Required	Description
`block_id`	Yes	ID of the memory block to update
`value`	No	New value for the memory block (optional)
`metadata`	No	New metadata for the memory block (optional)
`agent_id`	No	Optional agent ID for authorization

Implementation Reference

src/tools/memory/update-memory-block.js:4-49 (handler)

The handler function that implements the core logic for the 'update_memory_block' tool: validates inputs, prepares update data, makes a PATCH request to the Letta API to update the memory block, and returns the response.

export async function handleUpdateMemoryBlock(server, args) {
    try {
        // Validate arguments
        if (!args?.block_id) {
            throw new Error('Missing required argument: block_id');
        }

        if (!args?.value && !args?.metadata) {
            throw new Error('Either value or metadata must be provided');
        }

        // Headers for API requests
        const headers = server.getApiHeaders();

        // If agent_id is provided, set the user_id header
        if (args.agent_id) {
            headers['user_id'] = args.agent_id;
        }

        // Prepare update data
        const updateData = {};
        if (args.value !== undefined) {
            updateData.value = args.value;
        }
        if (args.metadata !== undefined) {
            updateData.metadata = args.metadata;
        }

        // Update the memory block
        const response = await server.api.patch(`/blocks/${args.block_id}`, updateData, {
            headers,
        });

        // Format the response
        return {
            content: [
                {
                    type: 'text',
                    text: JSON.stringify(response.data),
                },
            ],
        };
    } catch (error) {
        server.createErrorResponse(error);
    }
}

src/tools/memory/update-memory-block.js:54-80 (schema)

The tool definition including name, description, and input schema for 'update_memory_block'.

export const updateMemoryBlockToolDefinition = {
    name: 'update_memory_block',
    description:
        'Update the contents and metadata of a memory block. Use list_memory_blocks to find block IDs, or read_memory_block to see current content before updating.',
    inputSchema: {
        type: 'object',
        properties: {
            block_id: {
                type: 'string',
                description: 'ID of the memory block to update',
            },
            value: {
                type: 'string',
                description: 'New value for the memory block (optional)',
            },
            metadata: {
                type: 'object',
                description: 'New metadata for the memory block (optional)',
            },
            agent_id: {
                type: 'string',
                description: 'Optional agent ID for authorization',
            },
        },
        required: ['block_id'],
    },
};

src/tools/index.js:167-168 (registration)
Registration of the 'update_memory_block' handler in the central tool dispatch switch statement within registerToolHandlers.
```
case 'update_memory_block':
    return handleUpdateMemoryBlock(server, request.params.arguments);
```

src/tools/index.js:25-27 (registration)

Import of the handler and tool definition for 'update_memory_block'.

    handleUpdateMemoryBlock,
    updateMemoryBlockToolDefinition,
} from './memory/update-memory-block.js';

src/tools/index.js:111-111 (registration)
Inclusion of updateMemoryBlockToolDefinition in the allTools array used for registration.
```
updateMemoryBlockToolDefinition,
```

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