Troubleshooting

Find your symptom below. Each section says what the error means and what to do about it.

My AI app can't reach Lune

If the connection fails outright, with a timeout or "couldn't reach the server":

Check the URL. The server is https://mcp.luneresearch.com. The older https://mcp.luneresearch.com/mcp and https://mcp.luneresearch.com/v1/mcp still work.
Check that your network reaches it. From a terminal:
```
curl -sS -o /dev/null -w "%{http_code}\n" \
  https://mcp.luneresearch.com/.well-known/oauth-protected-resource
```
You should see 200. A 5xx means Lune is having trouble. Try again in a few minutes, and email support if it doesn't clear. No answer at all points to a network or DNS problem on your side.
Open the status page. It checks from your browser whether the MCP server responds. It doesn't post incident reports.

Test the connection by hand

List the tools with an access key. This call doesn't count as a request.

curl -sS https://mcp.luneresearch.com \
  -H "Authorization: Bearer lune_your_access_key" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

A working key gets the tool list back as an event stream: an event: message line, then a data: line holding the JSON-RPC response. Other answers mean:

401: the key is wrong or revoked. See the next section.
405: the request went out as GET. The server takes POST only. A browser that opens the URL is sent to Connect Lune to your AI app instead.
406: the Accept header is missing one of its two types.
415: the Content-Type header isn't application/json.
400: the body isn't valid JSON, or a JSON-RPC batch had more than 50 messages. Fix the JSON or split the batch.
403 with "origin not allowed": the request came from a web page. Call the server from a backend or a native app.

I get "401 unauthorized" or "invalid_token"

The server didn't accept the credential.

Apps you connected by signing in (OAuth). The app renews its access token on its own. If the error keeps coming back, the sign-in has ended. Someone revoked it on the Credentials page, it went unused for 90 days, or a reused refresh token ended it. Disconnect Lune in the app and connect again.
Access keys. The key is mistyped, revoked, or past an expiry date set when it was created. Create a new key on the Credentials page and replace the old one. Members can revoke only their own keys; owners and admins can revoke any key in the team.
Suspended accounts. The hosted server answers a suspended account with the same 401 as a bad credential, and the local stdio server returns an error that says the account is suspended. If reconnecting never clears the 401, or you see that message, email appeal@luneresearch.com. New credentials won't help.

If you're building the connector

OAuth discovery starts with a request that has no credential:

POST to the server without an Authorization header. The 401 response carries WWW-Authenticate: Bearer resource_metadata="https://mcp.luneresearch.com/.well-known/oauth-protected-resource", scope="papers:read guidance:read account:read". An expired or unverifiable token gets the same header with error="invalid_token" added, which tells the client to refresh it.
Fetch that resource metadata. Its authorization_servers entry is https://api.luneresearch.com.
Fetch https://api.luneresearch.com/.well-known/oauth-authorization-server for the endpoints. Then register, authorize, and exchange the code as auth.md shows.

When the token endpoint refuses a form-encoded request, it answers 400 with a flat body, {"error": "...", "error_description": "..."}. A body that isn't form-encoded, or that lacks grant_type, gets 422 with a {"detail": [...]} list instead. Registration answers 422 when redirect_uris is missing and 400 when the list is empty or holds a URI it refuses. The common error values:

`error`	Cause	Fix
`invalid_grant`	The code expired after 10 minutes, was already used, or doesn't match the client ID, redirect URI, or PKCE verifier. Or the refresh token expired, was revoked, or was reused.	Start the authorization again.
`invalid_target`	`resource` differs from the value on the authorization request or on the refresh token.	Send `resource=https://mcp.luneresearch.com` on every request.
`invalid_redirect_uri`	Registration refused a redirect URI: `http` on a host other than loopback, a fragment, or an unsafe scheme.	Register an `https`, loopback, or private-use URI.

An authorization request fails with 400 when its redirect_uri isn't one of the registered URIs (character for character, except the port of an http loopback URI), and with 422 when scope is missing. auth.md lists the errors a client usually meets.

I get "403" or a missing-scope error

The credential works but lacks the scope a tool needs. The tool list shows every tool whatever the scopes; only the call fails.

OAuth. The server answers 403 with a WWW-Authenticate header whose error is insufficient_scope and whose scope names the missing scope. Disconnect Lune in the app and connect again. A client should authorize again with the full set, papers:read guidance:read account:read, because a new grant carries only the scopes its request names.
Access keys. The tool returns an error that names the missing scope. Create a key that includes it. Permissions lists which tools need which scope.

I'm out of requests, or I get "429"

These are two different limits.

Out of requests. When neither the daily allowance nor credits can cover a call, the tool returns an error whose last line carries http_status=402 and a quota_reason:

no_capacity: the daily allowance and credits are both used up. Wait for the reset at midnight UTC, buy credits, or upgrade on the Billing page. A credit pack is $0.99 for 300 extra requests.
batch_too_large: a batch tool asked for more items than your remaining allowance covers, and more than your credits cover. A call is paid from one or the other, never both. Retry with fewer queries, papers, or claims.
retry_now: capacity came back while the call was in flight. Retry it once.

429. A short per-second burst guard stops runaway scripts. It has nothing to do with your daily allowance. Wait the number of seconds in retry_after_seconds, retry the same call, and have the app make fewer calls at once.

Plans, requests & credits explains the allowance and how calls are counted.

My AI app connects but the tools don't show up

Restart the AI app. Most clients fetch the tool list only at startup.
In a web AI app, remove the connector and add it again.
In Claude Desktop, quit fully (closing the window isn't enough) and reopen it.

Tips for each kind of app are in Local AI agents and Web AI apps.

Requests count against the wrong team

Apps you connected by signing in always bill your personal team. An access key bills the team it was created in. To use a shared team's plan, create an access key in that team and connect with it. Teams & access keys has the details.

Search results look wrong, missing, or outdated

Coverage. Lune indexes top-tier peer-reviewed venues. The Venues page and the list_conferences tool list the venues whose main-track papers are all indexed. Search also finds papers from venues Lune is still completing. A paper from any other venue isn't in the corpus.
Freshness. Lune adds a venue's new papers when it next crawls that venue. Crawls run by hand, not on a schedule, so a recent paper can take weeks to appear.
Phrasing. A full natural-language query ("methods for retrieval-augmented generation that reduce hallucination on long-form QA") finds more than a keyword list ("RAG hallucination").
Venue filters. A conference name Lune doesn't know returns an error, not unfiltered results. A venues list keeps the names Lune knows and drops the rest, and fails if it knows none of them. An ambiguous name returns the candidates to choose from. Ask the agent to check list_conferences for the exact short names.

I'm still stuck

Email support@luneresearch.com with:

the AI app you use (Claude, Cursor, and so on)
the tool name, if the error came from a tool call
when it happened, in UTC
the exact error text
whether it's a new setup or one that used to work

We usually reply the same day.