meter: the call leaves no transcript (finding meter-transcripts-need-no-keeping)

--no-session-persistence on the meter's call only: it keeps no handle and
resumes nothing, and every other call is resumed by its session.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/claude-connector/src/backend.rs

@@ -177,7 +177,7 @@ impl ClaudeCodeBackend {
         request.input = vec![InputItem::UserText {
             text: "ok?".to_string(),
         }];
-        match self.run(&request, METER_CALLER).1 {
+        match self.run(&request, METER_CALLER, true).1 {
             TransportOutcome::Completed { usage, .. } => Ok(usage),
             TransportOutcome::Failed { kind, .. } => Err(format!("{kind:?}")),
         }
@@ -189,10 +189,13 @@ impl ClaudeCodeBackend {
         binary_matches_pin(&self.config)
     }
 
+    /// `ephemeral` leaves no transcript behind: the meter keeps no handle and
+    /// resumes nothing, every other call is resumed by its session.
     fn run(
         &self,
         request: &ProviderRequest,
         caller: &str,
+        ephemeral: bool,
     ) -> (Vec<TransportEvent>, TransportOutcome) {
         let Some(secret) = usable_secret(self.handle_secret.as_ref()) else {
             return failed(
@@ -236,7 +239,7 @@ impl ClaudeCodeBackend {
                 "claude-code: the system prompt could not be staged",
             ));
         };
-        let argv = argv(&self.config, request, &plan, prompt.path());
+        let argv = argv(&self.config, request, &plan, prompt.path(), ephemeral);
         let env = child_env(&self.config, request);
         let deadline = Instant::now() + self.config.limits.deadline;
 
@@ -350,7 +353,7 @@ impl ProviderBackend for ClaudeCodeBackend {
     }
 
     fn execute(&self, call: &ProviderCall) -> TransportResult {
-        let (events, outcome) = self.run(call.request(), call.caller_runtime_id());
+        let (events, outcome) = self.run(call.request(), call.caller_runtime_id(), false);
         call.transported(events, outcome)
     }
 

crates/claude-connector/src/backend/tests.rs

@@ -2773,6 +2773,10 @@ fn the_meter_call_reads_the_week_from_a_real_captured_event() {
     let after = |flag: &str| argv[argv.iter().position(|a| a == flag).unwrap() + 1].clone();
     assert_eq!(after("--model"), METER_MODEL);
     assert_eq!(after("--tools"), "", "the call can use no tool");
+    assert!(
+        argv.iter().any(|a| a == "--no-session-persistence"),
+        "the meter's transcript is nobody's to keep: {argv:?}"
+    );
     assert_eq!(rig.spawns(), 1, "one child, never run again");
 }
 

crates/claude-connector/src/launch.rs

@@ -107,13 +107,15 @@ fn effort(effort: ReasoningEffort) -> &'static str {
 /// rather than an argument because one argument is capped near 128 KiB
 /// (E2BIG) and instructions are not, the child has
 /// no tools, no MCP servers, no settings, no slash commands and nobody to ask
-/// for permission, and a resume always forks. A request's output schema goes
-/// to the CLI as `--json-schema`; without one the flag is absent.
+/// for permission, and a resume always forks. An ephemeral call (the
+/// meter's) keeps no session on disk. A request's output schema goes to the
+/// CLI as `--json-schema`; without one the flag is absent.
 pub(crate) fn argv(
     config: &ClaudeCodeConfig,
     request: &ProviderRequest,
     plan: &Plan,
     system_prompt_file: &Path,
+    ephemeral: bool,
 ) -> Vec<String> {
     let mut argv: Vec<String> = [
         config.claude_binary.to_string_lossy().as_ref(),
@@ -139,6 +141,9 @@ pub(crate) fn argv(
     .into_iter()
     .map(str::to_string)
     .collect();
+    if ephemeral {
+        argv.push("--no-session-persistence".to_string());
+    }
     if let Some(level) = request.reasoning_effort {
         argv.extend(["--effort".to_string(), effort(level).to_string()]);
     }