Slack: Move run-creation notifications from Lambda to web app

[wasimxyz]

Summary

Slack notifications previously fired once per file processed by the Lambda — producing multiple "Finished preprocessing run X" messages per run, which contradicted the wording. They now fire once per newly-created run, from the web app's POST /api/v1/instruments/:instrumentId/runs endpoint, gated on the onConflictDoNothing upsert actually inserting a row.

Changes

• New web-app/lib/slack.ts (sendSlackMessage) — reads SLACK_WEBHOOK_URL, no-ops when unset, swallows errors so a Slack outage cannot fail the API request.
• POST .../runs posts one Slack message per isNew insert, using instruments.displayName and new URL(request.url).origin for the deep link.
• Lambda no longer imports/calls Slack: slack.send_message, INSTRUMENT_ID_TO_NAME_MAP, and get_cloudwatch_logs_url are gone from handler.py. Per-instrument process_file functions now return None (was str) and DATA_HUB_WEB_URL / lambda/src/data_hub_lambda/constants.py are deleted.
• data_hub_shared.slack and the SLACK_WEBHOOK_URL field on data_hub_shared.config are removed; SlackWebhookUrl is dropped from infra/template.yaml, the Makefile, deploy-lambda.yml, and the infra/.env.* / lambda/.env.example files.
• New integration test asserts a duplicate (instrument_id, run_id) POST captures exactly one Slack message. The capture infra is an in-process HTTP server in tests/integration/global-setup.ts exposed via getCapturedSlackMessages() / clearCapturedSlackMessages().
• Docs updated across lambda.md, architecture.md, shared-library.md, getting-started.md, ci-and-deployment.md, adding-an-instrument.md, and the root README.md.

Breaking changes

• SLACK_WEBHOOK_URL must be configured in Vercel per environment. It can be removed from the GitHub staging / production environment secrets and from infra/.env.staging / infra/.env.production — leaving the latter in place will fail sam deploy because the SAM parameter no longer exists.
• The data_hub_shared.slack module and config.SLACK_WEBHOOK_URL are gone; any external consumer would need to migrate (none exist in this repo).
• Per-instrument process_file return type changed from str to None.

Driveby changes

• Removed dead result_url assertions from lambda/tests/epson_v700_scanner/test_process_file.py.
• Updated the "adding an instrument" guide to reflect the new process_file signature.

Testing

• make check-all passes locally
• Integration test in web-app/tests/integration/instrument-runs.test.ts passes (duplicate POST → single Slack message)
• Lambda integration tests still pass with the mock_slack fixture removed
• After deploy: trigger a new run end-to-end and confirm a single Slack message lands; trigger a second file for the same run and confirm no second message
• Confirm sam deploy succeeds after removing SlackWebhookUrl from infra/.env.staging / infra/.env.production

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
data-hub	Ready	Preview, Comment	May 8, 2026 0:01am