Protocol contribution RFCs

This directory collects RFC-shaped documents that Burin Labs intends to contribute to upstream agent-protocol working groups. Each RFC describes a primitive that Harn already ships under a protocol's _meta extensibility slot, so the upstream proposal can reference a running reference implementation instead of starting from a design sketch.

Filing pattern

The Harn convention for cross-protocol primitives is:

Ship the reference implementation first under the protocol's designated extensibility slot (_meta for ACP / MCP, the JSON-RPC envelope's metadata for A2A). This proves the shape end-to-end without disturbing upstream consumers.
Author an RFC document in this directory. Each RFC is written as a neutral standards-grade proposal: problem statement, wire-format schema, compatibility story, reference-impl status, and open questions for maintainers. The wire-format snippet matches the upstream repo's preferred dialect (TypeScript for ACP, JSON Schema for MCP, A2A JSON-RPC envelope for A2A).
Open an upstream discussion when the RFC is ready. Use the RFC doc as the source of truth for the discussion body so reviewers work from a single shared text. Do not expand scope inside the filed thread — drift looks bad and complicates maintainer triage.
Track outcomes here. When a proposal lands upstream, update the RFC's "Status" header and migrate the Harn _meta envelope to the standardized field locations in a follow-up PR. When a proposal is declined, record the decision in the RFC and keep the _meta shape stable for downstream consumers.

Current RFCs

Ambient reminder injection (#1829)

RFC	Upstream	Status	Reference impl
ACP `session/inject_reminder`	agentclientprotocol/agent-client-protocol	Discussion open (ACP #1224)	`session/remind` JSON-RPC method + `_meta.harn.reminder`-decorated transcript events
A2A `Message.kind: "Reminder"`	a2aproject/A2A	Draft (not yet filed upstream)	`_meta.harn.reminder` on outbound A2A task messages
MCP `notifications/reminder`	modelcontextprotocol/specification	Draft (not yet filed upstream)	`_meta.harn.reminder` on MCP server-emitted notifications

Suspend / resume + paused state (#1848)

RFC	Upstream	Status	Reference impl
ACP `session/suspend`	agentclientprotocol/agent-client-protocol	Draft (not yet filed upstream)	`__host_worker_suspend` builtin + `_meta.harn.suspend`-decorated session updates; sibling to the already-shipped `session/resume` (ACP #1726)
A2A `TaskState.PAUSED`	a2aproject/A2A	Draft (not yet filed upstream)	`metadata.harn.pause`-decorated `tasks/statusUpdate` SSE events

Scope

Authoring RFC documents in this repository is in scope for these PRs. Filing upstream discussions, issues, or PRs is the maintainer's explicit action — not a step any Harn contributor should take without the project owner asking for it. See #1829 for the upstream work that remains open.

Harn ACP/MCP extensions v1 — the authoritative list of Harn-owned _meta fields that ride alongside upstream protocol payloads today.
System reminders — the language-level reminder primitive the reminder-injection RFCs are proposing to standardize.
Transcript architecture — the underlying transcript event model that produces and consumes reminders.
suspend_agent / resume_agent builtins — the language-level cooperative suspend primitive the suspend/resume RFCs are proposing to standardize.