add_observations
Add new observations to existing entities in the knowledge graph
LABSCO SUMMARY
What the assistant learned last week is still there next week, and is still correctable.
Facts attach to entities and entities connect to each other, so a detail about a person or a project is stored once and found from either end rather than restated in every prompt. The delete tools are the part that matters over time: delete_observations removes one wrong statement without taking down the entity it was attached to, so the graph can be corrected rather than rebuilt.
What it is
A knowledge-graph memory backed by DuckDB: eight tools that create entities and relations, attach observations to entities, search and open nodes, and delete any of the three.
What you get
- Entities created several at a time
- Relations between entities, written in active voice
- Observations added in batches to entities that already exist
- Search across nodes by query, and opening named nodes directly
- Granular deletion: whole entities together with their relations, individual observations, or individual relations
Requirements
npx on your PATH. MEMORY_FILE_PATH is optional; set it to choose where the DuckDB database file is kept. No account, no key.
Setup effort
One command — npx -y @izumisy/mcp-duckdb-memory-server
USE CASES
01
Remembering a team's people and projects between sessions
Create the entities once, connect them with relations written in active voice, and attach what you learn as observations — so next week's session starts from the graph instead of from a re-explanation.
02
Recalling what is already known about a name
Search when you have a phrase and open when you have the exact names — the second is the cheaper path once the first has told you what the entity is called.
03
Correcting something the assistant learned wrong
A single wrong statement is removed on its own, leaving the entity and everything else attached to it in place; deleting the entity itself takes its relations with it.
8 tools
Counted once with only startup setup. Other versions, modes or optional credentials may expose a different list.
create_entities
Create multiple new entities in the knowledge graph
create_relations
Create multiple new relations between entities in the knowledge graph. Relations should be in active voice
delete_entities
Delete multiple entities and their associated relations from the knowledge graph
delete_observations
Delete specific observations from entities in the knowledge graph
delete_relations
Delete multiple relations from the knowledge graph
open_nodes
Open specific nodes in the knowledge graph by their names
search_nodes
Search for nodes in the knowledge graph based on a query
BEFORE YOU INSTALL
What to know first
Tools you get
8 tools when we connected.
Requires
npx on PATH
CONTEXT COST
Light Standing cost
Rated by the size of the 8 tool definitions that ride along on every turn, not by how many there are
INSTALLATION
Connect your client
Add the block to your client, or run the command directly.
Server setup
Configuration file
JSON
{
"mcpServers": {
"mcp-duckdb-memory-server": {
"command": "npx",
"args": [
"-y",
"@izumisy/mcp-duckdb-memory-server"
]
}
}
}MEMORY_FILE_PATH is optional and sets where the DuckDB database file is kept. In the client configuration, add "env": {"MEMORY_FILE_PATH": "/path/to/your/memory.data"} to the entry; when running the npx command directly, set MEMORY_FILE_PATH in that shell's environment instead.
npx
TERMINAL
npx -y @izumisy/mcp-duckdb-memory-server
