One brain. Every runtime keeps its own model bill.
The same memory across Claude Code, OpenAI Codex (CLI and app) and Mistral Vibe today, with Hermes in alpha. Each runtime authenticates and pays for its own model; Hydrate is the local-first layer they share. Pin a fact in one and a fresh session in another recalls it, unprompted, without sending the conversation to any cloud Hydrate operates.
The wedge: every competitor is a single-runtime silo.
No other tool in the audited 2026-Q2 landscape demonstrates capture in one runtime and recall in another on a single machine without funnelling the conversation through a third-party hosted memory service. Because Hydrate is a layer rather than a runtime, an Author in one model family and a Critic in another can work over the same shared state, which is exactly what makes cross-model orchestration possible.
Runtimes today
Claude Code
stableNative hooks. Zero configuration, works on day one with your existing Claude subscription.
Codex CLI + app
stableOpenAI's Codex CLI and macOS app share the same local store. Authenticates via your ChatGPT subscription, not Hydrate.
Mistral Vibe
stableWired via hydrate vibe install. Receives shared project memory on the first tool call and contributes facts back.
Hermes
alphaNous Research's Hermes via an exclusive memory-provider plugin slot (early access). Reads shared identity into the system prompt; reads and writes project recall against the local daemon.
Alpha caveats: profile write-back is inert (v0.2), identity facts only prime other runtimes when pinned, and gateway binding needs broader live testing.
VS Code + Copilot
alphaExtension with an @hydrate chat participant plus Language Model Tools Copilot auto-invokes.
MCP clients
stableEvery MCP-aware client: Claude Desktop, Cursor, Cline, Zed, Gemini CLI, your own agent. One endpoint, the same memory.