Inspector

The Inspector page tries a server's tools without a separate MCP client: connect, see what the server offers, fill in a tool's arguments and call it. Everything goes through the management API, so stored credentials never reach the browser and the server needs no CORS headers.

Targets

Target	What it reaches	Credentials
Upstream	A registered upstream server, as the gateway reaches it for tool calls	The stored static headers and upstream OAuth, applied by the gateway
Endpoint	One of this gateway's endpoints, through its public MCP route	What a client of that endpoint presents, entered on the page
URL	Any Streamable HTTP MCP URL that is not registered	Headers entered on the page, one Name: value per line

An upstream with upstream OAuth uses the shared account, or, when each person connects their own, the account you connected. A service key has no account, so it cannot inspect such an upstream and gets 409.

An endpoint is inspected exactly as its clients see it: its authentication, its profile's annotations, the bundle's curation and its rate limits all apply. Enter an API key for that endpoint, or an OAuth access token issued for it; an endpoint that accepts anonymous calls needs nothing. The credential is used for that one request and never stored.

A URL must pass the gateway's egress policy, like every address an admin supplies; a URL in a blocked range is refused with egress_denied before anything is sent. The headers are used for that one request and never stored or logged.

What you can do

• Connect initialises a connection and shows the server's name and version, the MCP revision negotiated and the capabilities it advertises, then lists its tools.
• Ping checks that the server answers. Ping belongs to the handshake-era revisions; a server on the stateless revision answers it as unsupported, and the page shows that answer.
• Tools shows each tool's description, annotations and input schema. The call form is generated from the schema: required fields are marked, and Raw JSON shows the same arguments as a JSON object to edit. A schema the form cannot express (nested objects, arrays) opens in raw JSON.
• Call sends tools/call. Progress notifications appear as they arrive, then the result, or the error: a result with isError: true and a JSON-RPC error are both shown as errors. A tool annotated destructiveHint: true asks for confirmation first.

Every request connects, runs its one operation and disconnects, so the time a call took is shown beside the time connecting took. Nothing about an inspector session is kept on the gateway.

Logging, audit and metering

Target	Logged	Audited	Metered
Upstream, URL	Yes, with source=inspector and who inspected	No	No
Endpoint	As any client's request	Yes, as any client's call	Yes, through the metering hook

Calls through an endpoint are ordinary client calls, so an application layer may bill them. Use a test key or a test endpoint when that matters. The inspector advertises no client capabilities: a tool that asks the client for input (elicitation or sampling) fails rather than prompting you.

API

The page uses four management routes, each with a target naming the kind and the server:

curl -s https://gw.example.com/api/v1/inspector:list-tools \
  -H "Authorization: Bearer $SERVICE_KEY" -H "Content-Type: application/json" \
  -d '{"target": {"kind": "upstream", "name": "weather"}}'

Route	Answers
POST /api/v1/inspector:connect	Server info, protocol revision, capabilities, instructions and how long connecting took
POST /api/v1/inspector:ping	How long connecting and the ping took
POST /api/v1/inspector:list-tools	Every tool with its schemas and annotations
POST /api/v1/inspector:call-tool	Server-Sent Events: a progress event per notification, then one result or failure

A target that gives no MCP answer is 502 with a detail that starts with its connection state, such as unreachable or credential_required; in a call's stream it is the failure event.