diff --git a/bridged/src/main/java/dev/ltms/bridged/worker/OpenCodeLauncher.java b/bridged/src/main/java/dev/ltms/bridged/worker/OpenCodeLauncher.java
index a93d5b1..b2757e4 100644
--- a/bridged/src/main/java/dev/ltms/bridged/worker/OpenCodeLauncher.java
+++ b/bridged/src/main/java/dev/ltms/bridged/worker/OpenCodeLauncher.java
@@ -247,6 +247,21 @@ public final class OpenCodeLauncher extends HerdrPeerLauncher {
 
             ObjectNode root = JSON.createObjectNode();
             root.put("$schema", "https://opencode.ai/config.json");
+            // CB-523, opencode side: a worker that runs out of context dies mid-turn, and its reply
+            // — the entire point of the turn — is lost with it. Auto-compaction is therefore not an
+            // operator preference for a bridged worker, it is a condition of the turn contract.
+            //
+            // Stated deliberately even though it is redundant today: OPENCODE_CONFIG is MERGED over
+            // ~/.config/opencode/config.json rather than replacing it, so a worker already inherits
+            // an `auto: true` set at home. We do not want that inheritance to be what the guarantee
+            // rests on — the home file is outside this repo, differs per machine, and is not ours.
+            //
+            // Know the cost before removing it: this key WINS over the home config (verified — an
+            // OPENCODE_CONFIG value overrides the home value, it does not defer to it), so an
+            // operator who sets `compaction.auto: false` at home cannot turn it off for bridged
+            // workers. That is the intended trade for peers we spawn and whose turns we must land;
+            // if per-profile control is ever wanted, add a profile knob rather than dropping this.
+            root.putObject("compaction").put("auto", true);
 
             if (cfg.hasMcp()) {
                 Path charter = dir.resolve("reply-charter.md");
diff --git a/bridged/src/test/java/dev/ltms/bridged/worker/OpenCodeLauncherTest.java b/bridged/src/test/java/dev/ltms/bridged/worker/OpenCodeLauncherTest.java
index 3d93939..bf42fd1 100644
--- a/bridged/src/test/java/dev/ltms/bridged/worker/OpenCodeLauncherTest.java
+++ b/bridged/src/test/java/dev/ltms/bridged/worker/OpenCodeLauncherTest.java
@@ -74,6 +74,8 @@ class OpenCodeLauncherTest {
         // Assert on parsed structure, not substrings: the generated config is real JSON and its
         // whitespace is the formatter's business, not the contract's.
         JsonNode json = new ObjectMapper().readTree(Path.of(cfgPath).toFile());
+        assertTrue(json.path("compaction").path("auto").asBoolean(),
+                "spawned opencode peers explicitly enable automatic compaction");
         JsonNode bridge = json.path("mcp").path("bridge");
         assertEquals("remote", bridge.path("type").asText(), "bridge is mounted as a remote MCP server");
         assertEquals("http://127.0.0.1:8765/mcp", bridge.path("url").asText(),