diff --git a/bridged/bridged.example.yaml b/bridged/bridged.example.yaml
index 2c4f1fe..b4d730c 100644
--- a/bridged/bridged.example.yaml
+++ b/bridged/bridged.example.yaml
@@ -190,7 +190,11 @@ profiles:
# `bridge_spawn{profile:"gx10"}`, which bypasses placement entirely; only automatic
# selection skips it.
weight: 0.5
- maxLoad: 2 # max live workers on this profile (omit for unlimited)
+ # maxLoad: max live workers on this profile. Omit for unlimited. An explicit 0 (CB-585) caps
+ # the profile at zero live members — it is excluded from automatic placement and an explicit
+ # `bridge_spawn{profile:"gx10"}` against it is refused too; a cap holds even when the profile
+ # is named directly. Negative is refused at config load — there is no sane meaning for it.
+ maxLoad: 2
# gitTokenEnv: GITEA_TOKEN # opt-in: let this profile's workers open their own PR (CB-302)
# gitHostEnv: GITEA_HOST # defaults to GITEA_HOST; injected only with gitTokenEnv
# exhaustedPattern: "usage limit has been reached" # opt-in: classify a usage-limit refusal (CB-578)
diff --git a/bridged/src/main/java/dev/ltms/bridged/config/BridgedConfig.java b/bridged/src/main/java/dev/ltms/bridged/config/BridgedConfig.java
index 4c88a05..9bbb187 100644
--- a/bridged/src/main/java/dev/ltms/bridged/config/BridgedConfig.java
+++ b/bridged/src/main/java/dev/ltms/bridged/config/BridgedConfig.java
@@ -210,9 +210,20 @@ public record BridgedConfig(
* unreachable — an explicit {@code bridge_spawn{profile:"..."}} bypasses
* placement entirely and still resolves it. Weights among the remaining
* (non-excluded) candidates need not sum to 1.0; only their ratios matter.
- * @param maxLoad max live workers allowed on this profile at one time; absent or
- * non-positive ⇒ unlimited. Live means any session the registry still owns
- * (acquired and not yet released), in any state.
+ * @param maxLoad max live workers allowed on this profile at one time. Absent
+ * (unset/{@code null}) ⇒ unlimited — most profiles rely on this. An
+ * explicit {@code 0} (CB-585) means "cap this profile at zero live
+ * members": it is excluded from every automatic policy's candidate pool
+ * the same way a {@code weight <= 0} profile is (see
+ * {@code PlacementPolicyUtil.available()}, which already treats "at cap"
+ * and "excluded" alike), and an explicit
+ * {@code bridge_spawn{profile:"..."}} against it is refused too (see
+ * {@code CompositePeerLauncher.enforceMaxLoad}) — a cap is a capacity
+ * statement that does not stop being true just because the profile was
+ * named directly. A negative value has no sane meaning (there is no
+ * "excluded" to degrade to below zero) and is refused at config load
+ * instead, naming the profile and the key. Live means any session the
+ * registry still owns (acquired and not yet released), in any state.
* @param kind which peer launcher spawns this profile: {@code "claude-code"} (default —
* the {@link dev.ltms.bridged.member.ClaudeCodeLauncher}) or {@code "opencode"}.
* The {@code CompositePeerLauncher} routes {@code spawn}/reap by this value, so
@@ -306,7 +317,12 @@ public record BridgedConfig(
// get coerced back up to 1.0 — that coercion was the bug (weight: 0 looked like "never
// pick me" and actually meant "pick me as often as anyone else").
weight = (weight == null) ? 1.0f : Math.max(weight, 0.0f);
- maxLoad = (maxLoad == null || maxLoad <= 0) ? null : maxLoad;
+ // CB-585: absent still means unlimited (null), but an explicit maxLoad: 0 must survive
+ // as "capped at zero," not get coerced back up to null/unlimited — that coercion was
+ // the bug (maxLoad: 0 read as "never run anything here" and behaved as the opposite,
+ // the one throttle a subscription: true profile has against the operator's own paid
+ // plan). A negative value is refused earlier, at config load (rejectNegativeMaxLoad),
+ // so it never reaches this constructor and needs no clamping here.
subscription = (subscription != null && subscription) ? Boolean.TRUE : Boolean.FALSE;
// exhaustedPattern stays null when unset/blank (opt-in) — no defaulting, no vendor
// wording: an unconfigured profile keeps today's completion-fallback behaviour exactly.
@@ -956,6 +972,7 @@ public record BridgedConfig(
rejectLeaderTerminalKey(yaml);
warnUnknownTopLevelKeys(yaml, path);
rejectDuplicateMemberSlots(yaml);
+ rejectNegativeMaxLoad(yaml);
BridgedConfig cfg = YAML.readValue(yaml, BridgedConfig.class);
return cfg.withDefaults();
} catch (IOException e) {
@@ -1215,6 +1232,41 @@ public record BridgedConfig(
}
}
+ /**
+ * Reject a profile whose {@code maxLoad:} is negative, naming both the profile and the key.
+ *
+ *
Unlike {@code weight} (CB-554), where a negative value degrades to the same "excluded"
+ * meaning as an explicit {@code 0}, {@code maxLoad} has nowhere lower to degrade to — {@code 0}
+ * already means "capped at zero live members" (CB-585), the strictest cap there is. Silently
+ * normalising a negative value to something else is exactly the shape of bug this ticket fixes
+ * for {@code 0}, so it is refused instead, loud and specific, rather than guessed at.
+ *
+ * @param yaml the raw config text
+ * @throws IllegalStateException when any profile's {@code maxLoad} is negative
+ */
+ static void rejectNegativeMaxLoad(String yaml) {
+ Map, ?> raw;
+ try {
+ raw = YAML.readValue(yaml, Map.class);
+ } catch (IOException | IllegalArgumentException e) {
+ return; // a malformed file is reported by the real parse, not here
+ }
+ if (raw == null || !(raw.get("profiles") instanceof Map, ?> profiles)) {
+ return;
+ }
+ List bad = profiles.entrySet().stream()
+ .filter(e -> e.getValue() instanceof Map, ?> p
+ && p.get("maxLoad") instanceof Number n && n.doubleValue() < 0)
+ .map(e -> String.valueOf(e.getKey()))
+ .sorted()
+ .toList();
+ if (!bad.isEmpty()) {
+ throw new IllegalStateException("refusing to start: profile(s) [" + String.join(", ", bad)
+ + "] set a negative maxLoad — maxLoad caps live workers at a non-negative count;"
+ + " use 0 to cap a profile at zero live members, or omit the key for unlimited.");
+ }
+ }
+
static List unknownTopLevelKeys(String yaml) {
Map, ?> raw;
try {
diff --git a/bridged/src/test/java/dev/ltms/bridged/config/BridgedConfigTest.java b/bridged/src/test/java/dev/ltms/bridged/config/BridgedConfigTest.java
index 6cd306d..0cda820 100644
--- a/bridged/src/test/java/dev/ltms/bridged/config/BridgedConfigTest.java
+++ b/bridged/src/test/java/dev/ltms/bridged/config/BridgedConfigTest.java
@@ -1257,6 +1257,44 @@ class BridgedConfigTest {
assertEquals(0.0f, w.weight(), 0.0001f, "a negative weight behaves as excluded (0), not as an error and not as 1.0");
}
+ @Test
+ void explicitMaxLoadZeroStaysZeroInsteadOfCoercingToUnlimited(@TempDir Path dir) throws Exception {
+ // CB-585: maxLoad: 0 used to be normalised to null (unlimited) by this same compact
+ // constructor, so an operator writing it to mean "never run anything here" got the exact
+ // opposite. On a subscription: true profile, maxLoad is the only throttle against the
+ // operator's own paid plan.
+ Path f = dir.resolve("maxload-zero.yaml");
+ Files.writeString(f, """
+ bind:
+ port: 8080
+ profiles:
+ opus:
+ baseUrl: http://gx10.gw:8000
+ maxLoad: 0
+ """);
+
+ BridgedConfig cfg = BridgedConfig.load(f);
+ BridgedConfig.Profile w = cfg.profiles().get("opus");
+ assertEquals(0, w.maxLoad(), "an explicit maxLoad: 0 must stay 0, not coerce to unlimited (null)");
+ }
+
+ @Test
+ void negativeMaxLoadIsRefusedAtLoadNamingTheProfileAndKey(@TempDir Path dir) throws Exception {
+ Path f = dir.resolve("maxload-negative.yaml");
+ Files.writeString(f, """
+ bind:
+ port: 8080
+ profiles:
+ opus:
+ baseUrl: http://gx10.gw:8000
+ maxLoad: -2
+ """);
+
+ IllegalStateException e = assertThrows(IllegalStateException.class, () -> BridgedConfig.load(f));
+ assertTrue(e.getMessage().contains("opus"), "error names the profile: " + e.getMessage());
+ assertTrue(e.getMessage().contains("maxLoad"), "error names the key: " + e.getMessage());
+ }
+
@Test
void subscriptionFlagBindsAndDefaultsFalse(@TempDir Path dir) throws Exception {
Path f = dir.resolve("subscription.yaml");
diff --git a/bridged/src/test/java/dev/ltms/bridged/member/CompositePeerLauncherTest.java b/bridged/src/test/java/dev/ltms/bridged/member/CompositePeerLauncherTest.java
index 3028831..6fc01b0 100644
--- a/bridged/src/test/java/dev/ltms/bridged/member/CompositePeerLauncherTest.java
+++ b/bridged/src/test/java/dev/ltms/bridged/member/CompositePeerLauncherTest.java
@@ -473,6 +473,27 @@ class CompositePeerLauncherTest {
assertEquals("a", h.profile(), "a profile with no maxLoad is never capped, however many live workers");
}
+ @Test
+ void explicitSpawnOnMaxLoadZeroProfileIsRefusedEvenWithZeroLiveWorkers() {
+ // CB-585: before the fix, maxLoad: 0 normalised to null (unlimited) in the compact
+ // constructor, so this exact case — naming a zero-cap profile explicitly, with nothing
+ // live on it yet — would have spawned instead of refusing. "at most zero members" must
+ // hold even when the profile is named directly, not only against automatic placement.
+ FakeHerdr herdr = new FakeHerdr();
+ Map profiles = ordered(
+ "a", stubWorker("a", 1.0f, 0),
+ "b", stubWorker("b"));
+ StubLauncher adapter = new StubLauncher("claude", herdr, profiles, "a", Set.of());
+ CompositePeerLauncher composite = new CompositePeerLauncher(
+ List.of(adapter), "a", profiles, PlacementPolicies.fixed(), _ -> 0);
+
+ PlacementException e = assertThrows(PlacementException.class,
+ () -> composite.spawn(new SpawnRequest("a", null, null)));
+ assertTrue(e.getMessage().contains("'a'"), "message names the profile: " + e.getMessage());
+ assertTrue(e.getMessage().contains("0 cap"), "message names the zero cap: " + e.getMessage());
+ assertEquals(0, adapter.spawnCount("a"), "a maxLoad: 0 profile accepts no explicit spawn");
+ }
+
@Test
void emptyCandidateSetThrowsClearException() {
FakeHerdr herdr = new FakeHerdr();
diff --git a/bridged/src/test/java/dev/ltms/bridged/placement/PlacementPolicyTest.java b/bridged/src/test/java/dev/ltms/bridged/placement/PlacementPolicyTest.java
index cc2058f..c5dc42f 100644
--- a/bridged/src/test/java/dev/ltms/bridged/placement/PlacementPolicyTest.java
+++ b/bridged/src/test/java/dev/ltms/bridged/placement/PlacementPolicyTest.java
@@ -340,4 +340,31 @@ class PlacementPolicyTest {
void unknownPolicyNameThrows() {
assertThrows(IllegalArgumentException.class, () -> PlacementPolicies.fromName("random"));
}
+
+ // --- CB-585: maxLoad 0 caps a profile at zero live members, even with nothing live yet -----
+
+ @Test
+ void weightedSkipsMaxLoadZeroProfileEvenWithZeroLiveWorkers() {
+ PlacementPolicy policy = PlacementPolicies.weighted();
+ List candidates = List.of(
+ PlacementCandidate.profile("a", 1.0f, 0),
+ PlacementCandidate.profile("b", 1.0f, null));
+ Function liveCount = _ -> 0;
+ for (int i = 0; i < 5; i++) {
+ assertEquals("b", policy.select(ctx(candidates, liveCount)).profile(),
+ "a has maxLoad 0, so it is already at its cap with nobody live — every pick lands on b");
+ }
+ }
+
+ @Test
+ void weightedThrowsWhenAllMaxLoadZero() {
+ PlacementPolicy policy = PlacementPolicies.weighted();
+ List candidates = List.of(
+ PlacementCandidate.profile("a", 1.0f, 0),
+ PlacementCandidate.profile("b", 1.0f, 0));
+ Function liveCount = _ -> 0;
+ PlacementException e = assertThrows(PlacementException.class,
+ () -> policy.select(ctx(candidates, liveCount)));
+ assertTrue(e.getMessage().contains("maxLoad"), e.getMessage());
+ }
}