Adt API Discovery

ADT API Discovery — Skill

You are investigating SAP ADT REST API endpoints. Your goal is to determine the full HTTP contract for any endpoint: URL, HTTP methods, request/response XML format, content types, and headers.

Prerequisites

Before using this skill, run the abapfs_export_adt_discovery tool with the target connectionId. This creates a folder with markdown files containing the raw discovery data. Read these files first.

The ADT Architecture

Every ADT REST endpoint exists because of this chain:

SICF node: /sap/bc/adt
  └── Handler: CL_ADT_WB_RES_APP
        └── BAdI: BADI_ADT_REST_RFC_APPLICATION
              └── RES_APP class (inherits CL_ADT_DISC_RES_APP_BASE or CL_ADT_RES_APP_BASE)
                    └── register_resources() method
                          ├── registry->register_discoverable_resource(url, handler_class, ...)
                          ├── registry->register_resource(template, handler_class)
                          └── collection->register_disc_res_w_template(relation, template, handler_class)
                                └── Handler class (inherits CL_ADT_REST_RESOURCE)
                                      ├── GET/POST/PUT/DELETE method overrides
                                      ├── Content handler factory → get_handler_for_xml_using_st()
                                      └── response->set_body_data() / request->get_body_data()

Step-by-Step Investigation Process

Step 1: Find the endpoint in discovery

Search workspaces.md for the URL or keyword. This gives you the collection href and any template links (URL templates with parameters, relations, content types).

If the endpoint isn't in discovery, it may be a hidden resource — registered via register_resource() instead of register_discoverable_resource(). You'll find it in Step 2.

Step 2: Find the RES_APP class

The RES_APP class is what registers the endpoint. To find which one:

Option A — Match by URL pattern: The discovery URL /sap/bc/adt/oo/classes is registered by a RES_APP whose register_resources() method contains that URL. Search for it:

Use abapfs_search_object_source on RES_APP classes from res-app-classes.md, searching for the URL segment (e.g., '/oo/classes' or '/datapreview/')

Option B — Check RES_APP class names: The res-app-classes.md file lists all RES_APP classes with descriptions. Class names often hint at the feature area (e.g., CL_ADT_DATAPREVIEW_RES_APP → data preview, CL_OO_ADT_RES_APP → OO classes).

Option C — Use get_application_title(): Each RES_APP has a method get_application_title() that returns a title matching the discovery workspace title. Read the method source to match.

Step 3: Read register_resources() to find the handler class

Use abapfs_get_object_source to read the RES_APP class source. Look for three registration patterns:

" Pattern 1 — Discoverable resource (in /sap/bc/adt/discovery):
registry->register_discoverable_resource(
  url             = '/oo/classes'
  handler_class   = if_oo_adt_res_class_co=>co_class_name
  description     = 'Classes'
  category_scheme = ...
  category_term   = ...
  accepted_types  = ... ).

" Pattern 2 — Hidden resource (NOT in discovery):
registry->register_resource(
  template      = '/oo/classes/{classname}'
  handler_class = if_oo_adt_res_class_co=>co_class_name ).

" Pattern 3 — Template link on a collection:
classrun_col->register_disc_res_w_template(
  relation      = 'http://www.sap.com/adt/relations/oo/classrun'
  template      = '/oo/classrun/{classname}{?profilerId}'
  type          = if_rest_media_type=>gc_text_plain
  handler_class = if_oo_adt_res_classrun_co=>co_class_name ).

Step 4: Resolve the handler class name

The handler_class parameter is almost always a constant reference like if_oo_adt_res_class_co=>co_class_name. You need to resolve it:

1. Identify the interface/class before => (e.g., IF_OO_ADT_RES_CLASS_CO)
2. Read that interface's source with abapfs_get_object_source
3. Find CONSTANTS co_class_name TYPE ... VALUE 'CL_OO_ADT_RES_CLASS'

Naming convention: Handler classes typically have a companion *_CO interface that holds all constants:

• IF_OO_ADT_RES_CLASS_CO → constants for CL_OO_ADT_RES_CLASS
• IF_ADT_DATAPREVIEW_RES_CO → constants for CL_ADT_DATAPREVIEW_RES

These contain: co_class_name, co_accept_header_*, co_content_type_*, co_st_*, co_root_*, co_uri_*

Step 5: Determine HTTP methods

Read the handler class source. The base class CL_ADT_REST_RESOURCE defines GET/POST/PUT/DELETE methods that all raise cx_adt_res_meth_not_supported by default. A handler overrides only the methods it supports:

METHODS get  REDEFINITION.    " → GET is supported
METHODS post REDEFINITION.    " → POST is supported
" PUT and DELETE are NOT redefined → not supported

Search for REDEFINITION in the class definition section.

Step 6: Find Simple Transformations (XML schema)

The handler class uses CL_ADT_REST_CNT_HDL_FACTORY to create content handlers from Simple Transformations. Search the handler source for:

cl_adt_rest_cnt_hdl_factory=>get_instance( )->get_handler_for_xml_using_st(
  st_name      = co_st_name           " → resolve to e.g. 'ST_DATA_PREVIEW'
  root_name    = co_root_name         " → resolve to e.g. 'DATA_PREVIEW_TABLE_DATA'
  content_type = if_xxx=>co_content_type_v1  " → resolve to MIME type
)

All three parameters typically need constant resolution (same process as Step 4 — read the *_CO interface).

Step 7: Distinguish request vs response

Trace which content handler variable is used where:

" RESPONSE (output):
response->set_body_data(
  content_handler = lo_response_handler    " ← this handler's ST is the response format
  data            = ls_result ).

" REQUEST (input):
request->get_body_data(
  EXPORTING content_handler = lo_request_handler  " ← this handler's ST is the request format
  IMPORTING data = ls_request ).

• GET requests: Usually no request body. Only the response ST matters.
• POST/PUT requests: May have both request and response STs (sometimes different).

Step 8: Read the Simple Transformation source

Use abapfs_get_object_source with objectType = 'XSLT' to read the ST source:

### Step 9: Interpret the ST XML

Simple Transformations use `tt:` directives. Here's how to read them:

| ST Element | Meaning |
|-----------|---------|
| `<prefix:element>` | Actual XML element that appears in request/response |
| `<tt:value ref="$ref.FIELD"/>` | Data value placeholder — becomes the field value |
| `<tt:attribute name="attr" value-ref="$ref.FIELD"/>` | XML attribute with a data value |
| `<tt:loop ref="TABLE">` | Repeating element (array/table) |
| `<tt:cond s-check="not-initial(FIELD)">` | Optional/conditional element |
| `<tt:apply name="SubTemplate">` | Calls a named template within the same ST |
| `<tt:include name="OTHER_ST" template="xxx"/>` | Includes a template from another ST — read that ST too |
| `<tt:template name="xxx">` | Named template block |
| `<tt:template>` (unnamed) | Default/entry template |
| `<tt:root name="ROOT" type="..."/>` | Root data binding to ABAP structure |
| `xmlns:prefix="uri"` | Namespace declaration — include in output |

**Template call chain**: The unnamed (default) `<tt:template>` is the entry point. It calls named templates via `<tt:apply name="xxx">`. Follow the chain to build the full XML structure.

**Included STs**: `<tt:include name="ST_OTHER" template="xxx"/>` means you need to also read `ST_OTHER` with `abapfs_get_object_source`.

## Content Type Convention

SAP ADT content types follow this pattern:

application/vnd.sap.adt...v+xml

Examples:
- `application/vnd.sap.adt.datapreview.table.v1+xml`
- `application/vnd.sap.adt.oo.classes.v4+xml`

**The version number matters** — wrong version → 406 Not Acceptable.

## Key Base Classes

| Class | Role |
|-------|------|
| `CL_ADT_RES_APP_BASE` | Root base for all RES_APP classes |
| `CL_ADT_DISC_RES_APP_BASE` | Extends above, adds discovery support. Most RES_APPs inherit from this |
| `CL_ADT_REST_RESOURCE` | Base for all handler classes |
| `CL_ADT_REST_CNT_HDL_FACTORY` | Factory that creates content handlers from Simple Transformations |

## Example: Full Investigation of Data Preview

1. Search `workspaces.md` for "data preview" → find workspace "Data Preview" with collections like `/sap/bc/adt/datapreview/ddic`, `/sap/bc/adt/datapreview/cds`
2. From `res-app-classes.md`, `CL_ADT_DATAPREVIEW_RES_APP` matches
3. Read its `register_resources()` → finds `handler_class = if_adt_datapreview_res_co=>co_class_name`
4. Read `IF_ADT_DATAPREVIEW_RES_CO` → `co_class_name = 'CL_ADT_DATAPREVIEW_RES'`
5. Read `CL_ADT_DATAPREVIEW_RES` → `METHODS get REDEFINITION. METHODS post REDEFINITION.` → supports GET, POST
6. Find `get_handler_for_xml_using_st(st_name = co_st_name ...)` → resolve `co_st_name` from the `*_CO` interface → `'ST_DATA_PREVIEW'`
7. Read `ST_DATA_PREVIEW` with `objectType='XSLT'` → the XML structure with `dataPreview:tableData`, `dataPreview:totalRows`, etc.

## Tips

- **Search broadly first**: Use `abapfs_search_object_source` with wildcards on multiple RES_APP classes when unsure which one registers your endpoint
- **Read the `*_CO` interface early**: It usually contains ALL constants for the handler — class name, content types, ST names, root names, URI segments
- **Check for composite content handlers**: Some handlers use `CL_ADT_REST_COMP_CNT_HANDLER` to support multiple content types/versions. Look for `add_handler()` calls
- **Hidden endpoints are common**: Many endpoints are registered with `register_resource()` and don't appear in discovery. Check the RES_APP source directly