From 5fe3fec497496b568305c91ec408e6baabf50a77 Mon Sep 17 00:00:00 2001
From: Steffen Deusch <steffen@deusch.me>
Date: Tue, 17 Feb 2026 15:49:52 +0100
Subject: [PATCH 1/2] docs: add session/stop RFD

---
 docs/rfds/session-stop.mdx | 79 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 docs/rfds/session-stop.mdx

diff --git a/docs/rfds/session-stop.mdx b/docs/rfds/session-stop.mdx
new file mode 100644
index 00000000..47083abe
--- /dev/null
+++ b/docs/rfds/session-stop.mdx
@@ -0,0 +1,79 @@
+---
+title: "Stopping active sessions"
+---
+
+Author(s): [@SteffenDE](https://github.com/SteffenDE)
+
+## Elevator pitch
+
+> What are you proposing to change?
+
+We propose adding the ability to stop active sessions. This allows the agent to free up any memory
+and threads/subprocesses associated with that session.
+
+## Status quo
+
+> How do things work today and what problems does this cause? Why would we change things?
+
+Today, if you start a session, it will remain active until the ACP process is terminated.
+This means that if the agent implements sessions as separate processes, active users with
+many sessions can end up with a lot of processes unnecessarily using up system memory.
+Even if the agent does not spawn separate processes, memory used by large tool results or
+similar could still accumulate over time.
+
+The only way to free up that memory is to terminate the whole ACP process, which will stop
+all sessions and - if the agent does not support resuming sessions (load / resume / fork) -
+lead to a bad user experience.
+
+## What we propose to do about it
+
+> What are you proposing to improve the situation?
+
+Add a new `session/stop` method. If supported, the agent **must** cancel any ongoing work
+related to the session (treat it as if `session/cancel` was called) and then free up any resources
+associated with the session.
+
+## Shiny future
+
+> How will things will play out once this feature exists?
+
+Clients can track what sessions are actively used by a user and automatically stop old sessions.
+
+## Implementation details and plan
+
+> Tell me more about your implementation. What is your detailed implementation plan?
+
+We propose to add a new `"session/stop"` method. Agents must declare this option is
+available by returning `session: { stop : {} }` in their capabilities. The object is reserved
+to declare future capabilities.
+
+Then the client would be able to stop a specific session with:
+
+```json
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "method": "session/stop",
+  "params": {
+    "sessionId": "sess_789xyz"
+  }
+}
+```
+
+Agents might reply with an error if the session is not active or does not exist.
+
+## Frequently asked questions
+
+> What questions have arisen over the course of authoring this document or during subsequent discussions?
+
+None so far.
+
+### What alternative approaches did you consider, and why did you settle on this one?
+
+It could be an agent specific custom method, since we mainly ran into problems with Claude Code, but
+even for agents that don't spawn full subprocesses for sessions, cleaning up unneeded sessions still
+seems like a good idea.
+
+## Revision history
+
+<!-- If there have been major updates to this RFD, you can include the git revisions and a summary of the changes. -->

From b18f949e8c8709bc4f19cff1e84bff51c458dfa8 Mon Sep 17 00:00:00 2001
From: Ben Brandt <benjamin.j.brandt@gmail.com>
Date: Tue, 24 Feb 2026 15:43:55 +0100
Subject: [PATCH 2/2] Update website

---
 docs/docs.json             | 3 ++-
 docs/rfds/session-stop.mdx | 2 +-
 docs/updates.mdx           | 7 +++++++
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/docs/docs.json b/docs/docs.json
index d4013a28..74fb8fa5 100644
--- a/docs/docs.json
+++ b/docs/docs.json
@@ -122,7 +122,8 @@
               "rfds/message-id",
               "rfds/diff-delete",
               "rfds/boolean-config-option",
-              "rfds/elicitation"
+              "rfds/elicitation",
+              "rfds/session-stop"
             ]
           },
           {
diff --git a/docs/rfds/session-stop.mdx b/docs/rfds/session-stop.mdx
index 47083abe..88f432db 100644
--- a/docs/rfds/session-stop.mdx
+++ b/docs/rfds/session-stop.mdx
@@ -76,4 +76,4 @@ seems like a good idea.
 
 ## Revision history
 
-<!-- If there have been major updates to this RFD, you can include the git revisions and a summary of the changes. -->
+2026-02-24: Initial draft
diff --git a/docs/updates.mdx b/docs/updates.mdx
index d14d39b9..ef0bb209 100644
--- a/docs/updates.mdx
+++ b/docs/updates.mdx
@@ -4,6 +4,13 @@ description: Updates and announcements about the Agent Client Protocol
 rss: true
 ---
 
+<Update label="February 24, 2025" tags={["RFD"]}>
+## session/stop RFD moves to Draft stage
+
+The RFD for allowing agents to close or stop a given session has been moved to Draft stage. Please review the [RFD](./rfds/session-stop) for more information on the current proposal and provide feedback as work on the implementation begins.
+
+</Update>
+
 <Update label="February 24, 2025" tags={["RFD"]}>
 ## Elicitation RFD moves to Draft stage