n8n Postgres pgvector Consent Check + OpenAI Embeddings, Slack Alerts

Nightly PGVector embeddings only when consent allows—plus Slack alerts

This n8n workflow automatically reads unindexed knowledge base records from Postgres, checks each one against a Postgres consent register, and only generates OpenAI embeddings to store in pgvector when the required lawful conditions are satisfied. Decisions (included, refused, or held) are logged to a manifest and the workflow posts a summary to Slack whenever any records are refused or held.

What this workflow does

• Runs nightly on a schedule to keep your pgvector index up to date.
• Reads unindexed documents from kb_documents (using indexed_at to identify what still needs embedding).
• Loads consent information from a separate consent_register table in Postgres.
• Per-record consent matching & eligibility checks evaluate whether each document is eligible based on:
  • Required purpose
  • Retention window
  • Withdrawal status
  • Profiling objections
  • Special category flags
• Embeds only eligible text: eligible documents are chunked, embedded via OpenAI, and inserted into your pgvector index table with metadata.
• Writes an inclusion manifest entry recording the decision and lawful ground; marks eligible documents as indexed in Postgres.
• Logs refused/held decisions to the same manifest table with the specific refusal/hold ground.
• Posts a run report to Slack when any records are refused or held.

Use cases

• Keeping a consent-aware knowledge base index in sync for RAG search using pgvector.
• Preventing embedding of withdrawn or non-eligible records before they enter vector search.
• Operational compliance monitoring: Slack alerts highlight refused/held items for review.

Technical details

• Postgres integration: reads kb_documents + consent_register, stores vectors in a pgvector table, and writes to index_manifest.
• OpenAI embeddings: generates embeddings for eligible document chunks (model name must match your OpenAI access).
• Slack OAuth: sends notifications when refusals/holds occur.
• Workflow nodes/logic include: if, set, code, no op, merge, and slack.