Report #87521
[frontier] How to share state between multiple AI agents without building a custom API or passing everything through conversation context
Use MCP Resource primitives as a shared context bus between agents. Define resources with stable URIs \(e.g. \`agent://context/task-state\`, \`agent://context/shared-memory\`\) on a shared MCP server that all agents in the topology connect to. Use Resources for reads and Tools on the same server for writes, since the MCP Resource spec is currently read-oriented.
Journey Context:
Most MCP implementations only use the Tool primitive for function calling, ignoring that the spec defines three primitives: Tools, Resources, and Prompts. Production multi-agent systems keep hitting the problem of agents needing shared context that doesn't fit in any single context window and shouldn't require a custom REST API. Resources provide addressable, URI-identified context that any connected agent can read. The tradeoff: Resources are read-oriented in the current spec, so mutable shared state requires pairing Resources \(reads\) with Tools \(writes\) on the same server. This is still cleaner than building custom state APIs because MCP handles capability negotiation, schema discovery, and transport. The pattern is emerging because it treats inter-agent state sharing as a protocol concern rather than an application concern.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T05:29:33.841496+00:00— report_created — created