# Change

> Inspect graph changes over time and ontology version diffs in Semantica. Uses ContextGraph.state_at for point-in-time graph state and change_management.VersionManager for ontology versioning.

- Skill: `semantica-agi/change` (Agent Skill)
- Install (CLI): `npx skillmds@latest add semantica-agi/change`
- Raw SKILL.md: https://api.skillmd.com/api/skills/semantica-agi/change/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: semantica-agi (https://skillmd.com/u/semantica-agi)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/semantica-agi/change

---


# /semantica:change

Track what changed. Usage: `/semantica:change <task> [args]`

> Two distinct mechanisms cover this, and they are **not** interchangeable:
>
> | Question | Tool |
> | --- | --- |
> | "What did the *graph* look like on date X?" | `ContextGraph.state_at()` |
> | "What changed between *ontology* versions?" | `change_management.VersionManager` |

---

## `graph-at <timestamp>` — point-in-time graph state

```python
import os
from semantica.context import ContextGraph

graph = ContextGraph()
graph.load_from_file(os.path.expanduser("~/.semantica/kg.json"))   # load_from_file does not expand ~

snapshot = graph.state_at("2026-06-01")      # str | int | float | datetime
```

Diff two moments by comparing node IDs — `state_at()["nodes"]` is a list of
dicts (unhashable), so compare the `id` fields, not the dicts themselves:

```python
before = graph.state_at("2026-06-01")
after  = graph.state_at("2026-09-01")
before_ids = {n["id"] for n in before["nodes"]}
after_ids  = {n["id"] for n in after["nodes"]}
added = after_ids - before_ids
```

For richer temporal work (scrubbing, evolution, temporal patterns) use
`/semantica:temporal`, which wraps the same layer.

---

## `node-history <node_id>` — who touched this node

Node-level history is provenance, not change management:

```python
import os
from semantica.provenance import ProvenanceManager

db_path = os.path.expanduser("~/.semantica/prov.db")   # storage_path is passed to
os.makedirs(os.path.dirname(db_path), exist_ok=True)   # sqlite3.connect() unexpanded
pm = ProvenanceManager(storage_path=db_path)
history = pm.revision_history(node_id)
log     = pm.audit_log(since="2026-01-01")
```

---

## `versions` / `diff <v1> <v2>` — ontology versioning

```python
from semantica.change_management import VersionManager

vm = VersionManager()
vm.create_version("1.1.0", ontology)
vm.list_versions()
vm.get_latest_version()

delta = vm.compare_versions("1.0.0", "1.1.0")
delta = vm.diff_ontologies(base_ontology, target_ontology)
migrated = vm.migrate_ontology("1.0.0", "1.1.0", ontology)
```

`TemporalVersionManager` and `OntologyVersionManager` are also exported for
time-scoped and ontology-specific variants.