META OCT27 MATRIX

How to run the Oct 27 matrix before cutover

Use this sequence when Meta’s all-versions Graph/Marketing changes might break a pinned integration. Pair it with the interactive matrix.

Meta’s Graph API v26 materials state that selected legacy protocol behaviours and the Commerce Order Management API apply to all remaining supported versions beginning 27 October 2026. Pinning an older version does not skip those entries. The steps below turn the changelog into a release runbook.

  1. Open the official all-versions sections. Read the Graph API changelog v26.0 entries for legacy protocol and Commerce Order Management, plus the July 29, 2026 developer blog. Note loud errors versus silent behaviour changes.
  2. Answer the matrix on this site. Select pin belief, legacy habits, commerce sync, and Marketing surfaces. Copy the path, search strings, and checklist into your incident channel.
  3. Run a repository and workflow string scan. Search application code, mobile clients, and automation (n8n/Make HTTP modules) for date_format, root ?ids=, If-None-Match/ETag, pretty, debug, and commerce_orders.
  4. Fix loud legacy failures first. Drop date_format and convert default ISO timestamps locally. Replace root GET /?ids= with per-object calls or a batch POST (up to 50), and rewrite code that expected an ID-keyed map.
  5. Resize quiet pollers. If you relied on 304 Not Modified via ETag, assume full bodies after cutover and re-check rate and parse cost.
  6. Treat commerce hits as product decisions. Meta states no replacement API. Plan how Facebook/Instagram checkout orders will be handled operationally once Graph endpoints stop.
  7. Self-check Marketing quiet drops. Confirm delivery_estimate field readers, messenger story positions, and poll creatives against the Marketing all-versions notes.
  8. Verify with runtime logs on cutover week. Optionally compare with Meta’s API Upgrade Tool for traffic-based detections, then re-read live docs the morning of 27 October — Meta has moved dates before.

This checklist does not submit changes to Meta, does not run your Upgrade Tool, and is not a substitute for reading the live changelog.