Hex Plugin

The Hex plugin uses Hex’s hosted MCP server so Slack users can run analytical queries against the data warehouse from Junior.

Junior exposes only Hex’s create_thread and get_thread MCP tools. These support creating new analysis threads and polling for results — the core primitives needed for data retrieval workflows.

Requires a Hex Team or Enterprise plan.

Install

Install the plugin package alongside @sentry/junior:

pnpm add @sentry/junior @sentry/junior-hex

Runtime setup

List the plugin in juniorNitro({ plugins: { packages: [...] } }):

nitro.config.ts

juniorNitro({
  plugins: {
    packages: ["@sentry/junior-hex"],
  },
});

Auth model

• No HEX_API_TOKEN or shared secret is required.
• Each user completes OAuth the first time Junior calls a Hex MCP tool on their behalf.
• Junior sends the authorization link privately, then resumes the same thread automatically after the user authorizes.

Region configuration

The default MCP endpoint is https://app.hex.tech/mcp. For non-standard deployments, set HEX_MCP_URL in your environment:

Deployment	HEX_MCP_URL
Standard	(leave unset — uses default)
Single-tenant	https://your-company.hex.tech/mcp
EU multi-tenant	https://eu.hex.tech/mcp
HIPAA	https://hc.hex.tech/mcp

Skills

The plugin ships one skill:

• hex — Creates a Hex thread, polls for completion, and extracts results against a caller-provided pattern.

What users can do

• Query data from the Hex data warehouse using natural language or raw SQL.
• Get structured output suitable for downstream processing or display.

Verify

Confirm a real user can connect and query successfully:

1. Ask Junior to check usage data for a known Sentry customer.
2. Complete the private OAuth flow when Junior prompts for it.
3. Confirm the thread resumes automatically and includes Hex query results.
4. Open Junior App Home and confirm Hex appears under Connected accounts.

Failure modes

• No auth prompt or no resume: the user still needs to complete the OAuth flow. Retry the request and finish the private authorization flow when prompted.
• Query timeout: Hex threads can take time to process. The hex skill polls up to 10 times with 20-second intervals. Complex queries may need to be simplified.
• No data returned: verify the entity identifier in the prompt matches what’s in the warehouse. Narrow the query and try again.
• Wrong Hex workspace: verify HEX_MCP_URL points to the correct deployment if your org uses a custom Hex domain.

Next step

Review Credentials & OAuth and Security Hardening.