SAP Discovery Center integration

Status: rebuilt in PR #1685 (2026-08-12). Open contract question with the DC team — see Open questions before trusting in PROD.

What this is

SAP Discovery Center (discovery-center.cloud.sap) embeds tutorial cards that link out to developers.sap.com tutorials. To render a card, DC needs the GitHub source repo of the tutorial — it loads and renders the tutorial content from GitHub, not from our site.

Under the old Adobe Experience Manager (AEM) frontend, DC obtained that link by fetching a per-tutorial AEM Sling Model export:

https://developers.sap.com/tutorials/<slug>.model.json

AEM was decommissioned at PROD cutover (2026-08-09), so that path 404'd and DC's tutorial cards stopped rendering. This integration rebuilds the same .model.json envelope from our own data so DC continues to work with zero changes on its side (Option A). A DC-side alternative also exists (/build/repo-catalog).

Why this was missed at migration: the AEM gap analysis (docs/historic/aem-gap-analysis.md §E14) closed "Crawlable JSON Endpoints" on the assumption that Akamai 403'd all JSON for public crawlers, so nothing consumed them. DC was Akamai-allowlisted (public curl still 403s today), so it was the one consumer that survived — flagged as an unchased concern (Open Question #5) but never linked to .model.json consumption. The schema itself was never captured because the live endpoint always 403'd crawlers; it was recovered from a 2023 Wayback Machine snapshot.

Request path

DC calls the same public URL it always has. The chain to our CAP handler:

DC  →  GET https://developers.sap.com/tutorials/<slug>.model.json
        │  (Akamai — DC is allowlisted; anonymous curl is 403'd at the edge)
        ▼
     approuter route  (approuter/xs-app.json)
        source:  ^/tutorials/(.+)\.model\.json(\?.*)?$
        target:  /content/tutorial-model/$1$2
        dest:    srv-api        authenticationType: none
        ▼
     CAP  GET /content/tutorial-model/*slug   (srv/server.js:450)
        handler: modelJsonHandler   (srv/lib/model-json-handler.js)
        envelope builder: buildModelJson   (srv/lib/model-json.js — pure, no DB)

The route is unauthenticated (authenticationType: none) — the legacy export was public, and the payload is metadata already public on GitHub. The srv-api route pattern in xs-app.json includes the (\?.*)?$ query group so ?<cachebuster> requests are not 404'd (see the approuter-build-route-needs-query-string-group gotcha).

Endpoint contract

Public URL	GET /tutorials/<slug>.model.json
Internal URL	GET /content/tutorial-model/<slug>
Auth	None (public)
Success	200 application/json; charset=utf-8, Cache-Control: public, max-age=300, X-Content-Source: db
Mixed-case slug	301 → /tutorials/<lowercase-slug>.model.json (query preserved)
Redirected tutorial	301 → target slug's .model.json (admin rename/redirect via redirectTo_ID)
Unknown / invalid slug	404 { "error": "Tutorial not found: <slug>" }
Build error	500 { "error": "model.json build failed" }

Slugs are lowercase-canonical (^[a-z0-9][a-z0-9-]*$); a stray .html / .json / .model.json suffix on the captured slug is stripped before lookup.

Response shape — the field DC parses

The response reproduces the deep AEM Sling Model tree. DC only needs one field: the GitHub link, which the legacy export placed inside the feedback "Contribute suggestion" button. It lives at exactly one location:

// JSONPath from the root of the .model.json document:
$[':items'].par[':items'].par1[':items'].contentParsys
  .buttonBar.feedbackModel.options[ linkType == "github" ].href

That href is a GitHub issue-creation URL:

https://github.com/<owner>/<repo>/issues/new?title=<title>&body=Tutorials:%20https://developers.sap.com/tutorials/<slug>.html%0A...

DC regexes the <owner>/<repo> out of that issue URL. Preserving the exact location and href shape of this options[] entry is the load-bearing part of the compatibility contract — everything else in the envelope is scaffolding for byte-shape parity.

The feedbackModel.options array is built in this order:

1. community (static — "Ask the community")
2. github (dynamic — present only when RepoCatalog has a repo for the slug)
3. survey (static — "Take our survey")

If a slug has no RepoCatalog entry, the github option is omitted (the array still has community + survey). A DC card for such a tutorial will not find a repo — treat a missing github option as "unknown repo", not an error.

Other populated metadata: title, description, tags (as a { label: titlePath } map), tutorialDescription.contributors (creator / owner / collaborators), proficiency, time, imsId (legacyId), and the technicalFields.metadata OG/Twitter block.

Data sources

modelJsonHandler hydrates the envelope from these entities (com.sap.developers.ims):

Field group	Source entity	Notes
Core metadata	Tutorials	title, description, legacyId, experienceTag, primaryTag, averageTimeToComplete, status, redirectTo_ID
github option owner/repo/branch	RepoCatalog (payload JSON)	Same source the admin tutorial-links use (srv/lib/tutorial-links.js). Fail-quiet: a catalog miss just drops the github option
tags	TutorialTags → Tags	{ label, titlePath }
contributors	TutorialContributors → Users	login resolved via Users.githubLogin

What is intentionally NOT reproduced

• tutorialBody.steps[] rendered HTML — the shape is kept ({ intro: '', steps: [] }) so consumers reading .tutorialBody.steps get an array, not undefined, but the steps are empty. DC renders tutorial content from GitHub via the repo link; we do not persist structured per-step HTML server-side (Steps stores only stepOrder
  • contentHash).
• Author/edit-mode chrome, live prerequisites/"you will learn" rich text — emitted as empty scaffolding to match the shape.

Alternative: /build/repo-catalog

If the DC team prefers a purpose-built, non-legacy contract over the AEM envelope, we already expose the catalog directly (Option B — requires a DC-side change):

GET /build/repo-catalog        (unauthenticated)
→ { "<slug>": { owner, repo, branch, visibility, defaultLang, topics }, ... }

Handler: srv/lib/repo-catalog.js (repoCatalogReadHandler); route approuter/xs-app.json ^/build/(...|repo-catalog|...). This is the cleaner long-term integration (no AEM-shaped scaffolding), but switching to it is a cross-team change DC must make; the .model.json shim exists so DC keeps working in the meantime.

Open questions

1. The recovered schema sample is from 2023. Confirm with the DC team which field they actually parse today, and get a current payload sample, before trusting the shim in PROD. The GitHub-link location above is our best reconstruction from the Wayback snapshot + code.
2. Long-term direction: does DC want to keep the .model.json shim indefinitely, or migrate to /build/repo-catalog? The shim carries AEM scaffolding we would otherwise be free to drop.

Related code & tests

• Builder (pure): srv/lib/model-json.js
• Handler (DB hydration): srv/lib/model-json-handler.js
• Route registration: srv/server.js:450
• Approuter route: approuter/xs-app.json (^/tutorials/(.+)\.model\.json(\?.*)?$)
• Catalog handler: srv/lib/repo-catalog.js
• Recovered legacy fixture: srv/lib/__tests__/fixtures/legacy-abap-create-project.model.json
• Unit tests: srv/lib/__tests__/model-json.test.js, srv/__tests__/lib/model-json-route.test.js