From 4bdc7ae11249487f0b47254c35bd7fcae32e4d44 Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Thu, 2 Apr 2026 02:29:48 -0400
Subject: [PATCH] Journal budget: count from structured data, not string
 matching

Count journal tokens directly from Vec<JournalEntry> instead of
scanning message text for prefix strings. Type system, not string
typing.

Co-Authored-By: Proof of Concept <poc@bcachefs.org>
---
 src/agent/runner.rs | 32 +++++++++++---------------------
 1 file changed, 11 insertions(+), 21 deletions(-)

diff --git a/src/agent/runner.rs b/src/agent/runner.rs
index fd027ea..7308504 100644
--- a/src/agent/runner.rs
+++ b/src/agent/runner.rs
@@ -186,7 +186,9 @@ impl Agent {
         let count = |s: &str| self.tokenizer.encode_with_special_tokens(s).len();
 
         let mut id_tokens: usize = 0;
-        let mut jnl_tokens: usize = 0;
+        let jnl_tokens: usize = self.context.journal.iter()
+            .map(|e| count(&e.content))
+            .sum();
         let mut conv_tokens: usize = 0;
         let mut in_conversation = false;
 
@@ -198,26 +200,13 @@ impl Agent {
                 continue;
             }
 
-            match msg.role {
-                Role::System => id_tokens += tokens,
-                Role::User => {
-                    let text = msg.content_text();
-                    if text.starts_with("[Earlier in this conversation") {
-                        jnl_tokens += tokens;
-                    } else if text.starts_with("Your context was just rebuilt") {
-                        jnl_tokens += tokens;
-                    } else if jnl_tokens == 0 && conv_tokens == 0 {
-                        // Personality context — part of identity
-                        id_tokens += tokens;
-                    } else {
-                        in_conversation = true;
-                        conv_tokens += tokens;
-                    }
-                }
-                _ => {
-                    in_conversation = true;
-                    conv_tokens += tokens;
-                }
+            if in_conversation {
+                conv_tokens += tokens;
+            } else if msg.role == Role::System || (!in_conversation && conv_tokens == 0) {
+                id_tokens += tokens;
+            } else {
+                in_conversation = true;
+                conv_tokens += tokens;
             }
         }
 
@@ -851,6 +840,7 @@ impl Agent {
         }
 
         self.context.journal = entries;
+        dbg_log!("[journal] context.journal now has {} entries", self.context.journal.len());
     }
 
     /// Re-render the context message in self.messages from live ContextState.