Tool reference · Knowledge graph & temporal facts
kg_add_fact
Records a dated fact as subject, predicate, object, and by default closes any earlier fact with the same subject and predicate.
local stdio server writes
When to use
- An architectural choice changed, for example the queue moved from Redis to RabbitMQ.
- You want to be able to ask later what was true on a given date.
- You want a clear history of a setting or dependency instead of overwriting notes.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
subjectrequired | string | — | — |
predicaterequired | string | — | — |
objectrequired | string | — | — |
confidence | number | 1 | — |
context | string | — | — |
project | string | "general" | — |
invalidate_previous | boolean | true | — |
valid_from | string | — | ISO 8601 time the fact became true; default now. Back-dated facts close and are closed by their neighbours. |
Example
Arguments
{
"subject": "my-api",
"predicate": "uses_queue",
"object": "rabbitmq",
"context": "Switched from Redis streams for delivery guarantees",
"project": "my-api"
}Result shape
{
"assertion_id": "5e0b7d2c9a1f4e3b8c6d0a2f4b6e8c1d"
}Adding the exact same fact again returns the id of the existing open assertion instead of creating a duplicate.
Values are illustrative; the keys follow the server's handler. MCP clients receive the result as JSON text content.
Server description
The description the server sends to your agent in tools/list, captured from the v14.7.0 source:
Record a temporal fact assertion (subject, predicate, object). Supersedes any prior assertion with same (s,p) and different object — full history is preserved. Use for evolving architectural decisions.