grpc/grpc-java · error · IllegalArgumentException

Unsupported input type

Error message

Unsupported input type: ${typeUrl}

What it means

resolveInput maps a TypedExtensionConfig to a MatchInput implementation via MatchInputRegistry. If no MatchInputProvider is registered for the config's type URL, the input extension is unknown to this runtime and it throws this IllegalArgumentException.

Solutions

1. Register a MatchInputProvider for the typeUrl in MatchInputRegistry.getDefaultRegistry() before parsing the matcher
2. Upgrade gRPC/xDS to a version that supports the requested input type
3. Replace the input with a supported input type in the config
4. Verify the '@type' URL exactly matches the registered provider key

Example fix

// before: unknown input typeUrl throws
MatchInput input = UnifiedMatcher.resolveInput(config);
// after: register the provider first
MatchInputRegistry.getDefaultRegistry().register(
    "type.googleapis.com/grpc.xds.Input.MyHeaderInput",
    c -> new HeaderInput(c));
MatchInput input = UnifiedMatcher.resolveInput(config);

String typeUrl = config.getTypedConfig().getTypeUrl();
boolean supported = MatchInputRegistry.getDefaultRegistry().getProvider(typeUrl) != null;

try { MatchInput in = UnifiedMatcher.resolveInput(cfg); } catch (IllegalArgumentException e) { log.error("Unsupported input " + e.getMessage()); fallbackInput(); }

When it happens

Trigger: Calling UnifiedMatcher.resolveInput with a TypedExtensionConfig whose typed config typeUrl has no provider in MatchInputRegistry.getDefaultRegistry() — e.g. an input extension type the gRPC version doesn't implement, a typo in '@type', or a custom input plugin that was never registered before matcher parsing.

Common situations: Envoy configs referencing input types (e.g. source IP, TLS fields) not yet ported to gRPC xDS; control-plane/client version skew; custom MatchInput extension not registered at startup; wrong type.googleapis.com URL casing or package name.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Unsupported custom_match matcher
• A terminal HttpFilter must be the last filter
• Address is not an IP
• All xds transports for authority are in backoff
• AndMatcher must have at least 2 predicates

AI-assisted analysis of grpc/grpc-java@64daddc1f3 (2026-09-08). Data as JSON: /api/errors/9a86106d1fe95bbc. Report an issue: GitHub.

Appendix: source

Thrown at xds/src/main/java/io/grpc/xds/internal/matcher/UnifiedMatcher.java:37

import com.github.xds.core.v3.TypedExtensionConfig;
import com.github.xds.type.matcher.v3.Matcher;
import java.util.function.Predicate;
import javax.annotation.Nullable;

/**
 * Represents a compiled xDS Matcher.
 */
abstract class UnifiedMatcher {

  static final int MAX_RECURSION_DEPTH = 16;
 
  abstract MatchResult match(MatchContext context);

  static MatchInput resolveInput(TypedExtensionConfig config) {
    String typeUrl = config.getTypedConfig().getTypeUrl();
    MatchInputProvider provider = MatchInputRegistry.getDefaultRegistry().getProvider(typeUrl);
    if (provider == null) {
      throw new IllegalArgumentException("Unsupported input type: " + typeUrl);
    }
    return provider.getInput(config);
  }

  /**
   * Parses a proto Matcher into a UnifiedMatcher.
   *
   * @param proto the proto matcher
   * @param actionValidator a predicate that returns true if the action type URL is supported
   */
  static UnifiedMatcher fromProto(Matcher proto,
      Predicate<String> actionValidator) {
    checkRecursionDepth(proto, 0);
    Matcher.OnMatch onNoMatch = proto.hasOnNoMatch() ? proto.getOnNoMatch() : null;
    if (proto.hasMatcherList()) {
      return new MatcherList(proto.getMatcherList(), onNoMatch, actionValidator);
    } else if (proto.hasMatcherTree()) {
      return new MatcherTree(proto.getMatcherTree(), onNoMatch, actionValidator);

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