conductor-oss/conductor · error · IllegalArgumentException

Unknown termination type in nested composite: ${type}

Error message

Unknown termination type in nested composite: ${type}

What it means

Thrown by buildNestedSubConditionBody() when a sub-condition inside a nested composite (an and/or inside another and/or) has an unrecognized type. This is the same validation as errors 33/35 but for the deepest nesting level reached via the buildInlineComposite recursion path.

Source

Thrown at agentspan/src/main/java/org/conductoross/conductor/ai/agentspan/runtime/compiler/TerminationCompiler.java:468

        return sb.toString();
    }

    /**
     * Build an inline sub-condition body for use inside a nested composite. Variable names are
     * prefixed to avoid collisions.
     */
    private static String buildNestedSubConditionBody(
            TerminationConfig sub, String varName, int parentIndex, int childIndex) {
        String type = sub.getType();
        return switch (type) {
            case "text_mention" -> buildInlineTextMention(sub, varName);
            case "stop_message" -> buildInlineStopMessage(sub, varName);
            case "max_message" -> buildInlineMaxMessage(sub, varName);
            case "token_usage" -> buildInlineTokenUsage(sub, varName);
            case "and" -> buildInlineComposite(sub, varName, true, parentIndex * 10 + childIndex);
            case "or" -> buildInlineComposite(sub, varName, false, parentIndex * 10 + childIndex);
            default ->
                    throw new IllegalArgumentException(
                            "Unknown termination type in nested composite: " + type);
        };
    }
}

View on GitHub (pinned to cf7c3e4a8a)

Solutions

1. Traverse the full termination tree to find the specific sub-condition at the deepest nesting level whose type is invalid.
2. Fix that sub-condition's type to one of: text_mention, stop_message, max_message, token_usage, and, or.
3. Use a recursive validator to catch all type errors before compilation.

Example fix

// before: deepest nested sub has typo "stop" instead of "stop_message"
// and > or > [max_message, stop]
// after: fix "stop" to "stop_message"

private static final Set<String> VALID = Set.of(
    "text_mention", "stop_message", "max_message", "token_usage", "and", "or");

void validateAllNestedTypes(TerminationConfig config) {
    if (config.getType() == null || !VALID.contains(config.getType())) {
        throw new IllegalArgumentException("Invalid type at depth: " + config.getType());
    }
    if (config.getConditions() != null) {
        for (TerminationConfig sub : config.getConditions()) {
            validateAllNestedTypes(sub);  // recurse into all nesting levels
        }
    }
}

static boolean allNestedTypesValid(TerminationConfig root) {
    if (root.getType() == null || !VALID_TERM_TYPES.contains(root.getType())) return false;
    if (root.getConditions() == null) return true;
    return root.getConditions().stream().allMatch(x -> allNestedTypesValid(x));
}

try {
    String script = TerminationCompiler.buildTerminationScript(rootConfig);
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("Unknown termination type in nested composite")) {
        // recursively find the bad type at the deepest nesting level
    }
    throw e;
}

When it happens

Trigger: A nested composite TerminationConfig whose conditions list contains a TerminationConfig with a null or unrecognized type string. The error is caught at the nested level (parentIndex > 0), distinguishing it from error 35 which fires at the first nesting level.

Common situations: Same as error 35 but occurring at a deeper nesting level. A sub-condition inside a nested composite has a typo or null type. Harder to debug because the nesting obscures which condition is invalid.

Related errors

• Composite termination must have at least one sub-condition
• Composite termination (${isAnd ? "and" : "or"}) must have at
• Unknown termination type in composite: ${type}
• Unknown termination type: ${type}
• SWARM handoff type must be on_tool_result, on_text_mention,

AI-assisted analysis of conductor-oss/conductor@cf7c3e4a8a (2026-08-14). Data as JSON: /api/errors/6a40f5cc02692d01. Report an issue: GitHub.