Fabric is the canonical internal protocol for the iGentAI platform. It defines the shared method families, transport bindings, identity model, profile system, and adapter boundaries used by the services in the Concert stack.
Fabric is not a replacement name for ACP. ACP, MCP, A2A, and AG-UI are edge protocols that can be hosted beside Diminuendo when interoperability requires them. Fabric is the language the first-party services converge on.
What Fabric Owns
| Area | Fabric responsibility |
|---|---|
| Protocol shape | JSON-RPC method names, request/response envelopes, errors, IDs, and profile composition |
| Service boundaries | Which authority owns runtime, inference, resources, workspace sync, and presentation state |
| Transport bindings | HTTP JSON-RPC, HTTP + SSE, local JSONL stdio, internal binary frames, and partial WebSocket support |
| Authentication model | Bearer tokens at the gateway, scoped identity propagation between services, and per-profile permission expectations |
| SDK family | TypeScript, Rust, Go, Python, and Swift client/server helpers aligned around the same protocol concepts |
| Adapter rules | How external protocols project into Fabric without becoming the internal source of truth |
Authorities
| Authority | Primary service | Fabric profiles |
|---|---|---|
| Client/session gateway | Diminuendo | Core, conversation, presentation, stream, capability, selected resource/runtime brokering |
| Runtime | Podium | Runtime, stream, capability |
| Inference | Ensemble | Inference, model capability |
| Configuration/resources | Unison | Resource, sync, cluster, REST compatibility |
| Workspace | Chronicle | Workspace, sync, content-addressed storage |
The division is intentional. A client should not need to know every internal route to have a useful Fabric session, but operators and agents still benefit from clear service ownership.
First-Party Clients
The current first-party clients live under Diminuendo:
| Client | Purpose |
|---|---|
diminuendo/clients/web | Browser app served publicly at fabric.dev.aws.igent.ai |
diminuendo/clients/desktop | Tauri desktop shell |
diminuendo/clients/codex-tui | Terminal client |
ACP, MCP, A2A, and AG-UI implementations live under protocol sidecars. They are interoperability adapters, not additional first-party clients.
Mental Model
Fabric lets each component keep a tight job:
- Diminuendo makes the system feel like one coherent product surface.
- Podium turns runtime intent into supervised agent processes.
- Ensemble turns inference intent into provider requests and streamed results.
- Unison keeps configuration and resource state consistent.
- Chronicle makes workspace history and sync available when file authority is needed.
Everything else is a projection, adapter, deploy wrapper, or client surface around those authorities.