# Reported issues for mcp-trino Pod holds 22 of 24 problems reported by people outside the maintainer team. Issues filed by the project's own owners, members and collaborators are excluded entirely — a maintainer's release checklist is not a warning to a prospective user. Back to [mcp-trino](/mcp/mcp-trino). ## Most discussed ### Support for basic auth Where users are replying their own MCP server locally it should be possible and documented to support trino clusters using basic authentication by providing a password as environment variable. [Read the thread](https://github.com/tuannvm/mcp-trino/issues/159) · 2026-02-20 · open · external user · 1 comment ### Decimal(38,10) columns silently dropped from SELECT * query results Hi, when querying a PostgreSQL through Trino that contains decimal(38,10) columns, the MCP server silently drops these columns from the result set. No error is returned — the columns simply don't appear in the JSON output. **Steps to reproduce:** Have a PostgreSQL view with a numeric(32,10) column (maps to decimal(38,10) in Trino) **Query via MCP execute_query:** ``` SELECT * FROM catalog.public.my_view LIMIT 1; ``` -- Result: amount column is missing from JSON output **Workaround — casti [Read the thread](https://github.com/tuannvm/mcp-trino/issues/153) · 2026-02-06 · closed · external user · 1 comment ### Feat: document setup with LibreChat I am trying to use this MCP with LibreChat as client: https://github.com/danny-avila/LibreChat I am having a lot of trouble getting the oauth to work. For context: I am using Azure AD for oauth in an enterprise context. This might be a lot to ask, but would it be possible for you to add some documentation on how to configure the MCP in LibreChat? [Read the thread](https://github.com/tuannvm/mcp-trino/issues/127) · 2025-10-30 · closed · external user · 1 comment ### Token validation failed I can connect to mcp server, but token verification failed. OAuth: Validating token for tool list_catalogs: hJYK6wSu5afG9JMBjK0QOHddo+q69rnzYF9OGR7EDQM= 2025/09/05 10:56:56 OAuth: Token validation failed for tool list_catalogs: failed to parse and validate token: token is malformed: token contains an invalid number of segment [Read the thread](https://github.com/tuannvm/mcp-trino/issues/91) · 2025-09-05 · closed · external user · 2 comments ### SSL Verify is it possible to skip TLS verify for internal dev and testing? What would be the env variable to use for this? setting `TRINO_SSL_INSECURE=true` does not work and the cert is still verified ( Eg:- I get hostname verification errors ``` docker run -i --rm -p 8080:8080 -e -e TRINO_SSL_INSECURE=true -e MCP_TRANSPORT=http -e TRINO_ALLOW_WRITE_QUERIES=false -e TRINO_HOST=mytrinoserver -e TRINO_PORT=443 -e TRINO_USER=user -e TRINO_PASSWORD=password -e TRINO_SCHEME=https ghcr.io/tuannvm/mcp-trino:l [Read the thread](https://github.com/tuannvm/mcp-trino/issues/88) · 2025-08-25 · open · external user · 6 comments ### OAuth doesn't work with Claude Code I tried both Google OAuth and HMAC OAuth. The configurations work in Cursor, but not in Claude Code. Working Cursor config: ``` { "mcpServers": { "mcp-trino-https": { "url": "https://remote-server.example.com:9096/sse", "headers": { "Authorization": "Bearer " } } } } ``` To note: Not using in localhost mode, the MCP Go Server sits on another publically accessible machine [Read the thread](https://github.com/tuannvm/mcp-trino/issues/75) · 2025-08-07 · closed · external user · 2 comments ### brew install fails - Error: mcp-trino: Failed to download resource "mcp-trino" % brew tap tuannvm/mcp ==> Tapping tuannvm/mcp Cloning into '/opt/homebrew/Library/Taps/tuannvm/homebrew-mcp'... remote: Enumerating objects: 108, done. remote: Counting objects: 100% (108/108), done. remote: Compressing objects: 100% (60/60), done. remote: Total 108 (delta 43), reused 89 (delta 28), pack-reused 0 (from 0) Receiving objects: 100% (108/108), 29.60 KiB | 866.00 KiB/s, done. Resolving deltas: 100% (43/43), done. Tapped 3 formulae (17 files, 57.1KB). % brew install mcp-trino ==> Dow [Read the thread](https://github.com/tuannvm/mcp-trino/issues/56) · 2025-07-02 · closed · external user · 2 comments ### Enhancement Request: Support Trino OAuth2 Authentication Our Trino instance uses OAuth2 authentication by setting the `externalAuthentication` JDBC property to `true`. Are there plans for the MCP to support this type of authentication? Thank you [Read the thread](https://github.com/tuannvm/mcp-trino/issues/52) · 2025-06-11 · open · external user · 9 comments ## Most recent ### Looks like the arm64 container has an x86 binary I'm getting `exec ./trino-mcp: exec format error` when I run the helm chart against Bottlerocket arm64 nodes the tag I'm using is `4.3.1@sha256:7f74a66e97221a452ca900ba9d958db9b0867c0be85f65bad1322615923a8b6d` which correlates to the arm64 tag here: https://github.com/tuannvm/mcp-trino/pkgs/container/mcp-trino/772251807?tag=4.3.1 [Read the thread](https://github.com/tuannvm/mcp-trino/issues/219) · 2026-08-01 · open · external user · 1 comment ### OAuth scopes not configurable → `scopes_supported` omitted → Google (and strict IdPs) reject authorization with "Missing required parameter: scope" ## Summary When OAuth is enabled with an IdP that **requires a `scope` parameter** on the authorization request (e.g. Google), the interactive OAuth flow fails: mcp-trino never advertises `scopes_supported` in its RFC 9728 protected-resource metadata and provides no way to configure OAuth scopes. MCP clients (e.g. Claude Desktop/Code) derive the scopes to request from that metadata — with it absent they send **no `scope`**, and Google rejects the request: ``` Error 400: invalid_request — "Miss [Read the thread](https://github.com/tuannvm/mcp-trino/issues/217) · 2026-07-21 · open · external user · 0 comments ### feat: support configurable OIDC scopes via OIDC_SCOPES env var ## Problem When using `OAUTH_MODE=proxy` with providers like Okta or Azure AD that require `offline_access` to issue refresh tokens, there is no way to configure which OIDC scopes mcp-trino requests. The scopes are hardcoded inside `oauth-mcp-proxy`, so users cannot add the scopes their IdP needs. This blocks refresh-token-based flows in proxy mode — the access token expires and the client must re-authenticate from scratch. ## Proposed Solution Introduce an `OIDC_SCOPES` environment variable [Read the thread](https://github.com/tuannvm/mcp-trino/issues/209) · 2026-06-05 · open · external user · 0 comments ### Private security disclosure route? Hi, I have a security report for this project and did not find an enabled GitHub private vulnerability reporting route or SECURITY.md contact. Could a maintainer enable GitHub private vulnerability reporting or share the preferred private disclosure channel? I can provide the full technical details there. Thanks. [Read the thread](https://github.com/tuannvm/mcp-trino/issues/205) · 2026-05-20 · open · external user · 0 comments ### fix: persistent OAuth state signing key ## Context MCP Trino logs on startup: \`\`\` [WARN] No state signing key configured, generating random key (will not persist across restarts) \`\`\` This means OAuth state parameters are invalidated on every pod restart, causing in-flight auth flows to fail with "state does not match" errors. Related: #155 ## Current behavior Random signing key generated per process start. Pod restarts or rolling deploys break active OAuth flows. ## Desired behavior Read signing key from env var \`OAUTH_S [Read the thread](https://github.com/tuannvm/mcp-trino/issues/202) · 2026-05-07 · closed · external user · 1 comment ### feat: audit logging with OAuth user identity ## Context MCP Trino with OAuth enabled knows WHO is running each query (email, groups, roles from JWT). Currently this identity is used only for impersonation — it should also be logged for audit purposes. ## Desired behavior Every query execution logs: - User email/subject from JWT - Groups from JWT - Query text (truncated to 200 chars) - Timestamp - Duration - Row count - Success/failure Log format: structured JSON via slog (already used throughout codebase). Example: ```json {"level":"I [Read the thread](https://github.com/tuannvm/mcp-trino/issues/201) · 2026-05-07 · closed · external user · 0 comments ### feat: group-based catalog allowlist ## Context With Keycloak groups mapped to JWT `groups` claim, MCP Trino can restrict which Trino catalogs each group can access. ## Current behavior All authenticated users see all catalogs (`No Trino allowlists configured, all catalogs, schemas, and tables are accessible`). ## Desired behavior Configure catalog access per group via environment variable or config: ``` TRINO_GROUP_CATALOG_MAP=data-analysts:lake_curated,lake_landing;finance:finance_prd,finance_sbx;data-engineers:*;engineerin [Read the thread](https://github.com/tuannvm/mcp-trino/issues/200) · 2026-05-07 · closed · external user · 0 comments ### feat: role-based write query enforcement via JWT claims ## Context MCP Trino has `TRINO_ALLOW_WRITE_QUERIES` as a global toggle. With Keycloak OAuth now active (`lastro-internal` realm), we can enforce write access per-user based on JWT role claims. ## Current behavior - `TRINO_ALLOW_WRITE_QUERIES=false` → blocks ALL write queries for ALL users - `TRINO_ALLOW_WRITE_QUERIES=true` → allows ALL write queries for ALL users ## Desired behavior - Users with `mcp-readonly` role (default) → read-only queries only - Users with `mcp-admin` role → write qu [Read the thread](https://github.com/tuannvm/mcp-trino/issues/199) · 2026-05-07 · closed · external user · 0 comments ### MCP in Claude desktop failing with failed to verify signature: failed to verify id token signature HI I have beed to trying to add this trino mcp in claude desktop with oauth flow using azure as provider. I have set below env variables in my deployment ``` apiVersion: apps/v1 kind: Deployment metadata: name: trino-mcp namespace: etl spec: replicas: 1 selector: matchLabels: app: trino-mcp template: metadata: labels: app: trino-mcp spec: containers: - name: trino-mcp image: ghcr.io/tuannvm/mcp-trino:latest ports: [Read the thread](https://github.com/tuannvm/mcp-trino/issues/191) · 2026-04-22 · open · external user · 0 comments ### Request: Let CLI flags work when starting the MCP server Hi! I’ve been using `mcp-trino` version 4.3.0 on Windows, and I really appreciate the CLI mode and profile-based configuration. I noticed that in the new supported configuration, customized profiles in `~/config/trino/config.yaml` and flags like `--host`, `--port`, `--catalog`, `--user`, and `--password` work well for CLI commands, but they don’t seem to apply when starting the MCP server itself. Right now, running the server in HTTP mode always requires environment variables. It would be grea [Read the thread](https://github.com/tuannvm/mcp-trino/issues/173) · 2026-03-27 · open · external user · 0 comments ### Cannot access catalog memory I got `"failed to list tables: query execution failed: trino: query failed (200 OK): "USER_ERROR: Access Denied: Cannot access catalog memory": failed to list tables: query execution failed: trino: query failed (200 OK): "USER_ERROR: Access Denied: Cannot access catalog memory""` when i sue list_tables tool [Read the thread](https://github.com/tuannvm/mcp-trino/issues/166) · 2026-03-18 · open · external user · 0 comments ### Incorrect sanitizeQueryForKeywordDetection when sql start with like "-- comment\n " In trino/client.go, the isReadOnlyQuery function processes the query in this order: 1. Replace \n with spaces 2. Call sanitizeQueryForKeywordDetection() to remove comments The problem is that sanitizeQueryForKeywordDetection uses the regex --[^\r\n]* to match single-line comments, which relies on \n as the terminator. After step 1 replaces all \n with spaces, the -- comment regex matches from -- all the way to the end of the string (since there's no \n to stop it), effectively rem [Read the thread](https://github.com/tuannvm/mcp-trino/issues/161) · 2026-03-09 · open · external user · 0 comments ### State does not match - when refreshing token Hey folks 👋 I’ve deployed the server to a Kubernetes cluster and overall everything seems to be working fine. We’re using OAuth with Okta in our setup. The initial login flow works successfully. ``` "mcp-trino-http": { "url": "https://mcp-trino.qa.xxx.io/mcp" } ``` After the access token expires, VS Code prompts me again to open the browser for re-authentication. I accept, but during the callback step VS Code shows the following error: **State does not match**