Point your MCP client / Inspector at any URL below (Streamable HTTP; only the two auth scenarios want a credential). Click a URL to copy it.
Healthy baseline: https://chaos-mcp.thomascdnns.com/mcp · slow-response accepts ?delay=ms, controlled-delay is steered live from /control, and oauth-client-credentials wants a token you fetch with the client id and secret on its page.
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Baseline
healthyHealthy server (control)
Transport & framing
malformed-jsonTruncated / malformed JSON
not-json-rpcValid JSON, not JSON-RPC
wrong-content-typeWrong Content-Type
html-login-wallHTML login wall instead of JSON
empty-bodyEmpty 200 response
bom-garbageLeading garbage before JSON
Status & reliability
slow-responseVery slow response
controlled-delayToken-gated delay you set live
hang-foreverConnection hangs forever
always-500Always 500
flaky-500Flaky (50% errors)
rate-limitedRate limited (429)
broken-gzipLies about gzip encoding
Auth & OAuth
401-no-www-authenticate401 without WWW-Authenticate
oauth-dead-discoveryOAuth discovery dead-end
token-always-rejectedToken always rejected
oauth-client-credentialsOAuth with a client id and secret you supply
CORS & headers
no-corsNo CORS headers
no-session-idMissing Mcp-Session-Id
Protocol negotiation
bad-protocol-versionBogus protocol version
missing-capabilitiesMissing capabilities
bad-server-infoMalformed serverInfo
init-errorinitialize returns an error
Protocol versioning
version-downgradeAlways negotiates the oldest version
version-too-newNegotiates a version from the future
