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Hydrate vs OpenBrain / OB1
agent memory infraOne Postgres+pgvector brain that 9 AI clients share via MCP (~$0.10-0.30/mo). The closest cross-TOOL claim to Hydrate's cross-VENDOR pitch — but personal not team, static MCP notes not live decision capture.
What OpenBrain / OB1 is
| Stack / runtime | Postgres + pgvector (Supabase/free-tier cloud) + MCP server + chat interface |
| Licence | Open source |
| Storage | One shared Postgres 'thoughts' table with vector search |
| Hooks | None (MCP read/write; chat-channel input) |
| Injection | On-demand MCP query |
| Scope | Personal cross-tool brain; 9 clients (Copilot, Claude Code/Desktop, Cursor, Windsurf, ChatGPT, Gemini, Grok, any MCP) |
| Maturity | Open source; active |
| Price | ~$0.10-0.30/month on free-tier cloud |
| Version referenced | OB1 (Nate B. Jones) |
| Source | github.com/NateBJones-Projects/OB1 |
Where OpenBrain / OB1 leads
- Breadth: 9 named clients sharing one store via MCP today
- Cheap, self-hosted, open, you own the Postgres DB
- Dead-simple model (one table, one protocol, any client)
Where Hydrate leads
- Team (cross-machine, attribution) not just personal
- Live automatic decision capture + pre-prompt injection, not manual MCP notes
- Orchestration on the same substrate
- No hosted Postgres required; offline-capable single binary
Verification notes
STRONGEST cross-tool competitor to Hydrate's cross-vendor line — draw personal-vs-team and static-vs-live distinctions sharply. NAME COLLISION: NateBJones-Projects/OB1 vs srnichols/OpenBrain vs futurethang/open-brain — this entry tracks OB1; confirm which the doc means.
Sources
- Primary repo (OB1) https://github.com/NateBJones-Projects/OB1