molecule-core/docs/architecture/memory.md
Hongming Wang 24fec62d7f initial commit — Molecule AI platform
Forked clean from public hackathon repo (Starfire-AgentTeam, BSL 1.1)
with full rebrand to Molecule AI under github.com/Molecule-AI/molecule-monorepo.

Brand: Starfire → Molecule AI.
Slug: starfire / agent-molecule → molecule.
Env vars: STARFIRE_* → MOLECULE_*.
Go module: github.com/agent-molecule/platform → github.com/Molecule-AI/molecule-monorepo/platform.
Python packages: starfire_plugin → molecule_plugin, starfire_agent → molecule_agent.
DB: agentmolecule → molecule.

History truncated; see public repo for prior commits and contributor
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(workspace-template 1129 + sdk 132), vitest (canvas 352), build (mcp).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-13 11:55:37 -07:00

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Markdown

# Memory Architecture (HMA)
Molecule AI's memory model is built around one principle:
> memory boundaries should follow organizational boundaries.
That is the purpose of **HMA: Hierarchical Memory Architecture**.
## The Three Scopes
| Scope | Meaning | Intended use |
|---|---|---|
| `LOCAL` | visible only to the current workspace | private scratch facts and local recall |
| `TEAM` | visible to the local team boundary | handoffs between a parent and its direct children, or siblings under the same parent |
| `GLOBAL` | readable across the tree; writable only from the root side | org-wide guidance, standards, shared institutional knowledge |
These are the scopes exposed through the runtime memory tools:
- `commit_memory(content, scope)`
- `search_memory(query, scope)`
## What Exists In The Current Implementation
There are **multiple memory surfaces**, and the distinction matters.
### 1. Scoped agent memory (`agent_memories`)
This is the HMA-facing storage used by:
- `POST /workspaces/:id/memories`
- `GET /workspaces/:id/memories`
- runtime tools `commit_memory` / `search_memory`
It stores durable facts with a `LOCAL`, `TEAM`, or `GLOBAL` scope.
### 2. Workspace key/value memory (`workspace_memory`)
This is the simpler key/value surface used by the canvas `Memory` tab:
- `GET /workspaces/:id/memory`
- `POST /workspaces/:id/memory`
- `DELETE /workspaces/:id/memory/:key`
It is useful for structured per-workspace state and optional TTL entries. It is not the same thing as scoped HMA memories.
### 3. Activity recall (`session-search`)
`GET /workspaces/:id/session-search` provides a thin recall surface over recent activity rows and memory rows. It is for “what just happened in this workspace?” rather than long-term semantic storage.
### 4. Awareness-backed persistence
When the runtime receives:
```bash
AWARENESS_URL=...
AWARENESS_NAMESPACE=workspace:<id>
```
the same memory tools keep the same interface, but durable memory writes/reads are routed through the workspace's awareness namespace.
This is the current production direction of the memory boundary: stable tool surface, stronger backend isolation.
## Access Model
Molecule AI's memory rules follow the same hierarchy logic as communication rules:
- `LOCAL` belongs to one workspace
- `TEAM` follows the immediate team boundary
- `GLOBAL` is readable widely but writable only from the root side
The platform-side memory handlers still apply reachability checks for shared/team reads instead of trusting callers blindly.
## Current Schema Reality
The current `agent_memories` migration is intentionally simple:
```sql
CREATE TABLE IF NOT EXISTS agent_memories (
id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
workspace_id UUID REFERENCES workspaces(id),
content TEXT NOT NULL,
scope VARCHAR(10) NOT NULL CHECK (scope IN ('LOCAL', 'TEAM', 'GLOBAL')),
created_at TIMESTAMPTZ DEFAULT now(),
updated_at TIMESTAMPTZ DEFAULT now()
);
```
`pgvector` is **not enabled by default in the shipped migration**. The repo keeps vector support as an optional future extension, not as a current hard dependency. The docs should reflect that explicitly.
## Why This Architecture Matters
| Flat shared memory model | Molecule AI HMA |
|---|---|
| easy to over-share | scopes align to hierarchy |
| unclear ownership | each memory belongs to a workspace and a scope |
| recall and procedure blur together | memory stores facts, skills store repeatable procedure |
| hard to govern | org structure and memory rules reinforce each other |
## Memory To Skill Promotion
Molecule AI intentionally separates:
- **durable fact storage**
- **repeatable operational procedure**
The documented promotion path is:
1. a durable workflow is captured in memory
2. repeated success becomes a signal
3. the workflow is promoted into a skill package
4. the runtime hot-reloads that skill
This is why memory and skills are presented as adjacent systems, not one merged blob.
## Practical Summary
If you need:
- **private agent recall**: use `LOCAL`
- **shared team handoff knowledge**: use `TEAM`
- **org-wide guidance**: use `GLOBAL`
- **simple UI-visible structured state**: use `workspace_memory`
- **recent decision/task recall**: use `session-search`
- **stronger durable isolation**: enable awareness namespaces
## Related Docs
- [Workspace Runtime](../agent-runtime/workspace-runtime.md)
- [Skills](../agent-runtime/skills.md)
- [Communication Rules](../api-protocol/communication-rules.md)
- [Platform API](../api-protocol/platform-api.md)