diff --git a/README.md b/README.md
index 21b807e..d5f4d44 100644
--- a/README.md
+++ b/README.md
@@ -150,14 +150,15 @@ host-verified connection for another session.
 
 ### SFTP
 
-Called directly on a fresh connection, each SFTP method is one-shot: it opens
-its own channel and subsystem, runs the single operation, and closes. Downloads
-and uploads use `xstring` end to end:
+Use `zif_oassh_sftp_one_shot` on a fresh connection for one operation. It opens
+its own channel and subsystem, runs the operation, and closes the channel.
+Downloads and uploads use `xstring` end to end:
 
 ```abap
 DATA lv_file TYPE xstring.
+DATA li_sftp TYPE REF TO zif_oassh_sftp_one_shot.
 
-lo_ssh = zcl_oassh=>connect(
+li_sftp = zcl_oassh=>connect(
   iv_host          = 'ssh.example.com'
   iv_port          = '22'
   iv_user          = 'deploy'
@@ -165,13 +166,13 @@ lo_ssh = zcl_oassh=>connect(
   ii_host_verifier = lo_host_verifier ).
 
 TRY.
-    lv_file = lo_ssh->sftp_download(
+    lv_file = li_sftp->sftp_download(
       iv_path            = '/incoming/data.bin'
       iv_timeout_seconds = 60 ).
   CLEANUP.
-    lo_ssh->close( ).
+    li_sftp->close( ).
 ENDTRY.
-lo_ssh->close( ).
+li_sftp->close( ).
 ```
 
 The public SFTP methods are:
@@ -190,24 +191,26 @@ file.
 
 #### Multi-operation SFTP sessions
 
-To run several SFTP operations over a single authenticated connection, call
-`sftp_open` first. It performs the channel, subsystem, and INIT/VERSION
+To run several SFTP operations over a single authenticated connection, use
+`zif_oassh_sftp_session` and call `sftp_open` first. It performs the channel,
+subsystem, and INIT/VERSION
 handshake once; the same `sftp_*` methods then run inside that session until
 `sftp_close`. This avoids repeating the full SSH handshake — and, on APC, the
 one-byte-per-frame cost of every handshake — for each operation:
 
 ```abap
-lo_ssh = zcl_oassh=>connect( ... ).
+DATA li_sftp TYPE REF TO zif_oassh_sftp_session.
+li_sftp = zcl_oassh=>connect( ... ).
 TRY.
-    lo_ssh->sftp_open( ).
-    lt_names = lo_ssh->sftp_list( '/incoming' ).
-    lv_file  = lo_ssh->sftp_download( '/incoming/data.bin' ).
-    ls_attrs = lo_ssh->sftp_stat( '/incoming/data.bin' ).
-    lo_ssh->sftp_close( ).
+    li_sftp->sftp_open( ).
+    lt_names = li_sftp->sftp_list( '/incoming' ).
+    lv_file  = li_sftp->sftp_download( '/incoming/data.bin' ).
+    ls_attrs = li_sftp->sftp_stat( '/incoming/data.bin' ).
+    li_sftp->sftp_close( ).
   CLEANUP.
-    lo_ssh->close( ).
+    li_sftp->close( ).
 ENDTRY.
-lo_ssh->close( ).
+li_sftp->close( ).
 ```
 
 One SFTP operation runs at a time, and the session is not reused across
diff --git a/abaplint.jsonc b/abaplint.jsonc
index d069487..52b005d 100644
--- a/abaplint.jsonc
+++ b/abaplint.jsonc
@@ -38,6 +38,9 @@
     "begin_end_names": true,
     "begin_single_include": true,
     "call_transaction_authority_check": true,
+    "add_test_attributes": true,
+    "aff_and_xml": true,
+    "align_pseudo_comments": true,
     "cds_parser_error": true,
     "chain_mainly_declarations": true,
     "check_abstract": true,
diff --git a/docs/interactive-exec.md b/docs/interactive-exec.md
index 0a1025f..26eec1c 100644
--- a/docs/interactive-exec.md
+++ b/docs/interactive-exec.md
@@ -7,8 +7,8 @@ response, decide, and write the next request while the command keeps
 running. The canonical example is `git-upload-pack`, which GitHub exposes
 to deploy keys: ref advertisement down, `want`/`done` up, packfile down.
 
-The interactive exec API keeps the session channel open and hands the
-byte streams to the caller:
+The `zif_oassh_interactive_exec` interface keeps the session channel open and
+hands the byte streams to the caller:
 
 | Method | Purpose |
 | --- | --- |
@@ -31,18 +31,20 @@ command's output stream has ended (the peer sent `CHANNEL_EOF` or the
 connection closed). Callers therefore loop:
 
 ```abap
-DATA(lo_ssh) = zcl_oassh=>connect(
+DATA li_exec TYPE REF TO zif_oassh_interactive_exec.
+
+li_exec = zcl_oassh=>connect(
   iv_host          = 'github.com'
   iv_port          = '22'
   iv_user          = 'git'
   iv_private_seed  = lv_ed25519_seed   " the deploy key
   ii_host_verifier = li_verifier ).
 
-lo_ssh->exec_open( |git-upload-pack 'owner/repo.git'| ).
+li_exec->exec_open( |git-upload-pack 'owner/repo.git'| ).
 
 DATA(lv_advertisement) = VALUE xstring( ).
-WHILE lo_ssh->exec_is_closed( ) = abap_false.
-  DATA(lv_chunk) = lo_ssh->exec_read( ).
+WHILE li_exec->exec_is_closed( ) = abap_false.
+  DATA(lv_chunk) = li_exec->exec_read( ).
   IF lv_chunk IS INITIAL.
     EXIT. " timeout: decide whether the protocol layer has a complete unit
   ENDIF.
@@ -50,9 +52,10 @@ WHILE lo_ssh->exec_is_closed( ) = abap_false.
   " ... hand to a pkt-line parser, stop when it has the full advertisement
 ENDWHILE.
 
-lo_ssh->exec_write( lv_want_request ). " pkt-lines: want, deepen, flush, done
+li_exec->exec_write( lv_want_request ). " pkt-lines: want, deepen, flush, done
 " ... read the packfile with the same exec_read loop
-lo_ssh->exec_close( ).
+li_exec->exec_close( ).
+li_exec->close( ).
 ```
 
 ## Flow control
@@ -63,8 +66,8 @@ that do not fit are queued and sent automatically when the server's
 `exec_eof( )` refuses to half-close while stdin is still queued, because
 those bytes could never be delivered afterwards.
 
-Like every other operation on `zcl_oassh`, an interactive exec is the one
-operation of its connection object: `exec_open( )` on a connection that
+Like every other workflow, an interactive exec is the one operation of its
+connection object: `exec_open( )` on a connection that
 already ran an operation raises the usual typed error.
 
 ## Scope
diff --git a/docs/sftp-sessions.md b/docs/sftp-sessions.md
index 5db604e..77c5a66 100644
--- a/docs/sftp-sessions.md
+++ b/docs/sftp-sessions.md
@@ -1,8 +1,8 @@
 # Multi-operation SFTP sessions
 
-Each `sftp_*` method on `zcl_oassh` is one-shot by default: it authenticates,
-opens a session channel, starts the `sftp` subsystem, runs a single operation,
-and closes the channel. Every operation therefore pays for a full SSH handshake
+Each method on `zif_oassh_sftp_one_shot` authenticates, opens a session channel,
+starts the `sftp` subsystem, runs a single operation, and closes the channel.
+Every operation therefore pays for a full SSH handshake
 and a fresh subsystem — expensive when a caller needs several operations in a
 row, and especially so on APC, where each handshake is exchanged one byte per
 frame.
@@ -12,12 +12,12 @@ the channel, subsystem, and INIT/VERSION handshake once; the same `sftp_*`
 methods then run inside that single subsystem channel until `sftp_close`.
 
 ```abap
-DATA lo_ssh TYPE REF TO zcl_oassh.
-DATA lt_names TYPE zcl_oassh_sftp=>ty_names.
+DATA li_sftp TYPE REF TO zif_oassh_sftp_session.
+DATA lt_names TYPE zif_oassh_sftp_one_shot=>ty_names.
 DATA lv_data TYPE xstring.
-DATA ls_attrs TYPE zcl_oassh_sftp=>ty_attrs.
+DATA ls_attrs TYPE zif_oassh_sftp_one_shot=>ty_attrs.
 
-lo_ssh = zcl_oassh=>connect(
+li_sftp = zcl_oassh=>connect(
   iv_host          = 'ssh.example.com'
   iv_port          = '22'
   iv_user          = 'deploy'
@@ -25,18 +25,18 @@ lo_ssh = zcl_oassh=>connect(
   ii_host_verifier = lo_host_verifier ).
 
 TRY.
-    lo_ssh->sftp_open( ).                       " channel + subsystem + INIT/VERSION
-    lt_names = lo_ssh->sftp_list( '/incoming' ).
-    lv_data  = lo_ssh->sftp_download( '/incoming/data.bin' ).
-    ls_attrs = lo_ssh->sftp_stat( '/incoming/data.bin' ).
-    lo_ssh->sftp_rename(
+    li_sftp->sftp_open( ).                       " channel + subsystem + INIT/VERSION
+    lt_names = li_sftp->sftp_list( '/incoming' ).
+    lv_data  = li_sftp->sftp_download( '/incoming/data.bin' ).
+    ls_attrs = li_sftp->sftp_stat( '/incoming/data.bin' ).
+    li_sftp->sftp_rename(
       iv_old_path = '/incoming/data.bin'
       iv_new_path = '/incoming/data.bin.done' ).
-    lo_ssh->sftp_close( ).                       " channel close handshake
+    li_sftp->sftp_close( ).                       " channel close handshake
   CLEANUP.
-    lo_ssh->close( ).
+    li_sftp->close( ).
 ENDTRY.
-lo_ssh->close( ).
+li_sftp->close( ).
 ```
 
 ## API
@@ -52,8 +52,9 @@ lo_ssh->close( ).
 usual typed error, and a session is never reused across those other kinds or a
 second channel.
 
-Without `sftp_open`, every `sftp_*` method behaves exactly as before — one-shot,
-one connection per operation — so existing callers are unaffected.
+Use `zif_oassh_sftp_one_shot` when no reusable session is needed. The concrete
+SFTP methods on `zcl_oassh` are implementation details; callers select one of
+the two SFTP interfaces explicitly.
 
 ## Semantics
 
diff --git a/examples/zoassh_example_sftp.prog.abap b/examples/zoassh_example_sftp.prog.abap
index 86ac392..202cdac 100644
--- a/examples/zoassh_example_sftp.prog.abap
+++ b/examples/zoassh_example_sftp.prog.abap
@@ -44,8 +44,8 @@ START-OF-SELECTION.
 FORM run.
 
   DATA lo_host_verifier TYPE REF TO zif_oassh_host_verifier.
-  DATA lo_ssh           TYPE REF TO zcl_oassh.
-  DATA lt_names         TYPE zcl_oassh_sftp=>ty_names.
+  DATA li_sftp          TYPE REF TO zif_oassh_sftp_session.
+  DATA lt_names         TYPE zif_oassh_sftp_one_shot=>ty_names.
   DATA lv_filename      TYPE string.
   DATA lv_data          TYPE xstring.
   DATA lv_preview       TYPE string.
@@ -59,30 +59,30 @@ FORM run.
   TRY.
 * ii_random is optional on SAP: zcl_oassh defaults to zcl_oassh_random_secure,
 * which draws from the kernel-backed secure random source.
-      lo_ssh = zcl_oassh=>connect(
+      li_sftp = zcl_oassh=>connect(
         iv_host          = p_host
         iv_port          = p_port
         iv_user          = p_user
         iv_password      = p_pass
         ii_host_verifier = lo_host_verifier ).
       TRY.
-          lo_ssh->sftp_open( p_tmout ).
+          li_sftp->sftp_open( p_tmout ).
 
 * --- list a directory -----------------------------------------------------
-          lt_names = lo_ssh->sftp_list(
+          lt_names = li_sftp->sftp_list(
             iv_path            = p_dir
             iv_timeout_seconds = p_tmout ).
 
 * --- download a file ------------------------------------------------------
-          lv_data = lo_ssh->sftp_download(
+          lv_data = li_sftp->sftp_download(
             iv_path            = p_file
             iv_timeout_seconds = p_tmout ).
 
-          lo_ssh->sftp_close( p_tmout ).
+          li_sftp->sftp_close( p_tmout ).
         CLEANUP.
-          lo_ssh->close( ).
+          li_sftp->close( ).
       ENDTRY.
-      lo_ssh->close( ).
+      li_sftp->close( ).
 
       WRITE: / 'listing of', p_dir.
       SKIP.
diff --git a/scripts/check-public-api.test.mjs b/scripts/check-public-api.test.mjs
index fd3d3ae..530255b 100644
--- a/scripts/check-public-api.test.mjs
+++ b/scripts/check-public-api.test.mjs
@@ -4,6 +4,9 @@ import test from "node:test";
 
 const publicSources = [
   "../src/zcl_oassh.clas.abap",
+  "../src/zif_oassh_interactive_exec.intf.abap",
+  "../src/zif_oassh_sftp_one_shot.intf.abap",
+  "../src/zif_oassh_sftp_session.intf.abap",
   "../src/platform/zif_oassh_socket.intf.abap",
 ];
 
diff --git a/src/zcl_oassh.clas.abap b/src/zcl_oassh.clas.abap
index 772c891..390949c 100644
--- a/src/zcl_oassh.clas.abap
+++ b/src/zcl_oassh.clas.abap
@@ -4,6 +4,10 @@ CLASS zcl_oassh DEFINITION
 
   PUBLIC SECTION.
 
+    INTERFACES zif_oassh_interactive_exec.
+    INTERFACES zif_oassh_sftp_one_shot.
+    INTERFACES zif_oassh_sftp_session.
+
     CLASS-METHODS connect
       IMPORTING
         iv_host          TYPE string
@@ -27,29 +31,6 @@ CLASS zcl_oassh DEFINITION
         VALUE(rv_output)   TYPE string
       RAISING
         zcx_oassh_error.
-* Multi-operation SFTP session: sftp_open( ) performs the channel, subsystem
-* and INIT/VERSION handshake once, then the sftp_* methods below run inside
-* that single session until sftp_close( ). Without sftp_open( ) each sftp_*
-* method is one-shot (its own connection lifecycle), exactly as before.
-* See docs/sftp-sessions.md.
-    METHODS sftp_open
-      IMPORTING
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RAISING
-        zcx_oassh_error.
-    METHODS sftp_close
-      IMPORTING
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RAISING
-        zcx_oassh_error.
-    METHODS sftp_download
-      IMPORTING
-        iv_path            TYPE string
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RETURNING
-        VALUE(rv_data)     TYPE xstring
-      RAISING
-        zcx_oassh_error.
     METHODS shell
       IMPORTING
         iv_input           TYPE xstring
@@ -61,97 +42,6 @@ CLASS zcl_oassh DEFINITION
         VALUE(rv_output)   TYPE xstring
       RAISING
         zcx_oassh_error.
-* Interactive exec: exec_open starts a command and returns while the channel
-* stays open, so the caller can interleave binary stdin and stdout, for
-* example to speak a request/response protocol such as git-upload-pack.
-* The conversation ends with exec_close. See docs/interactive-exec.md.
-    METHODS exec_open
-      IMPORTING
-        iv_command         TYPE string
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RAISING
-        zcx_oassh_error.
-    METHODS exec_write
-      IMPORTING
-        iv_data TYPE xstring
-      RAISING
-        zcx_oassh_error.
-    METHODS exec_read
-      IMPORTING
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RETURNING
-        VALUE(rv_data)     TYPE xstring
-      RAISING
-        zcx_oassh_error.
-    METHODS exec_eof
-      RAISING
-        zcx_oassh_error.
-    METHODS exec_close
-      IMPORTING
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RAISING
-        zcx_oassh_error.
-    METHODS exec_is_closed
-      RETURNING
-        VALUE(rv_closed) TYPE abap_bool.
-    METHODS sftp_upload
-      IMPORTING
-        iv_path            TYPE string
-        iv_data            TYPE xstring
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RAISING
-        zcx_oassh_error.
-    METHODS sftp_stat
-      IMPORTING
-        iv_path            TYPE string
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RETURNING
-        VALUE(rs_attrs)    TYPE zcl_oassh_sftp=>ty_attrs
-      RAISING
-        zcx_oassh_error.
-    METHODS sftp_lstat
-      IMPORTING
-        iv_path            TYPE string
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RETURNING
-        VALUE(rs_attrs)    TYPE zcl_oassh_sftp=>ty_attrs
-      RAISING
-        zcx_oassh_error.
-    METHODS sftp_list
-      IMPORTING
-        iv_path            TYPE string
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RETURNING
-        VALUE(rt_names)    TYPE zcl_oassh_sftp=>ty_names
-      RAISING
-        zcx_oassh_error.
-    METHODS sftp_mkdir
-      IMPORTING
-        iv_path            TYPE string
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RAISING zcx_oassh_error.
-    METHODS sftp_rmdir
-      IMPORTING
-        iv_path            TYPE string
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RAISING zcx_oassh_error.
-    METHODS sftp_remove
-      IMPORTING
-        iv_path            TYPE string
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RAISING zcx_oassh_error.
-    METHODS sftp_rename
-      IMPORTING
-        iv_old_path        TYPE string
-        iv_new_path        TYPE string
-        iv_timeout_seconds TYPE i DEFAULT 300
-      RAISING zcx_oassh_error.
-    METHODS sftp_realpath
-      IMPORTING
-        iv_path                TYPE string
-        iv_timeout_seconds     TYPE i DEFAULT 300
-      RETURNING VALUE(rs_name) TYPE zcl_oassh_sftp=>ty_name
-      RAISING zcx_oassh_error.
     METHODS get_stderr
       RETURNING
         VALUE(rv_output) TYPE string.
@@ -238,6 +128,95 @@ CLASS zcl_oassh DEFINITION
     DATA mv_disconnected TYPE abap_bool.
     DATA mv_disconnect_reason TYPE i.
 
+* Concrete implementations shared by the workflow interfaces.
+    METHODS exec_open
+      IMPORTING
+        iv_command         TYPE string
+        iv_timeout_seconds TYPE i DEFAULT 300
+      RAISING zcx_oassh_error.
+    METHODS exec_write
+      IMPORTING iv_data TYPE xstring
+      RAISING zcx_oassh_error.
+    METHODS exec_read
+      IMPORTING iv_timeout_seconds TYPE i DEFAULT 300
+      RETURNING
+        VALUE(rv_data)             TYPE xstring
+      RAISING zcx_oassh_error.
+    METHODS exec_eof RAISING zcx_oassh_error.
+    METHODS exec_close
+      IMPORTING iv_timeout_seconds TYPE i DEFAULT 300
+      RAISING zcx_oassh_error.
+    METHODS exec_is_closed
+      RETURNING VALUE(rv_closed) TYPE abap_bool.
+    METHODS sftp_open
+      IMPORTING iv_timeout_seconds TYPE i DEFAULT 300
+      RAISING zcx_oassh_error.
+    METHODS sftp_close
+      IMPORTING iv_timeout_seconds TYPE i DEFAULT 300
+      RAISING zcx_oassh_error.
+    METHODS sftp_download
+      IMPORTING
+        iv_path            TYPE string
+        iv_timeout_seconds TYPE i DEFAULT 300
+      RETURNING
+        VALUE(rv_data)     TYPE xstring
+      RAISING zcx_oassh_error.
+    METHODS sftp_upload
+      IMPORTING
+        iv_path            TYPE string
+        iv_data            TYPE xstring
+        iv_timeout_seconds TYPE i DEFAULT 300
+      RAISING zcx_oassh_error.
+    METHODS sftp_stat
+      IMPORTING
+        iv_path            TYPE string
+        iv_timeout_seconds TYPE i DEFAULT 300
+      RETURNING
+        VALUE(rs_attrs)    TYPE zif_oassh_sftp_one_shot=>ty_attrs
+      RAISING zcx_oassh_error.
+    METHODS sftp_lstat
+      IMPORTING
+        iv_path            TYPE string
+        iv_timeout_seconds TYPE i DEFAULT 300
+      RETURNING
+        VALUE(rs_attrs)    TYPE zif_oassh_sftp_one_shot=>ty_attrs
+      RAISING zcx_oassh_error.
+    METHODS sftp_list
+      IMPORTING
+        iv_path            TYPE string
+        iv_timeout_seconds TYPE i DEFAULT 300
+      RETURNING
+        VALUE(rt_names)    TYPE zif_oassh_sftp_one_shot=>ty_names
+      RAISING zcx_oassh_error.
+    METHODS sftp_mkdir
+      IMPORTING
+        iv_path            TYPE string
+        iv_timeout_seconds TYPE i DEFAULT 300
+      RAISING zcx_oassh_error.
+    METHODS sftp_rmdir
+      IMPORTING
+        iv_path            TYPE string
+        iv_timeout_seconds TYPE i DEFAULT 300
+      RAISING zcx_oassh_error.
+    METHODS sftp_remove
+      IMPORTING
+        iv_path            TYPE string
+        iv_timeout_seconds TYPE i DEFAULT 300
+      RAISING zcx_oassh_error.
+    METHODS sftp_rename
+      IMPORTING
+        iv_old_path        TYPE string
+        iv_new_path        TYPE string
+        iv_timeout_seconds TYPE i DEFAULT 300
+      RAISING zcx_oassh_error.
+    METHODS sftp_realpath
+      IMPORTING
+        iv_path            TYPE string
+        iv_timeout_seconds TYPE i DEFAULT 300
+      RETURNING
+        VALUE(rs_name)     TYPE zif_oassh_sftp_one_shot=>ty_name
+      RAISING zcx_oassh_error.
+
     METHODS handle_transport_message
       IMPORTING
         iv_payload        TYPE xstring
@@ -316,7 +295,7 @@ CLASS zcl_oassh DEFINITION
         iv_lstat           TYPE abap_bool
         iv_timeout_seconds TYPE i
       RETURNING
-        VALUE(rs_attrs)    TYPE zcl_oassh_sftp=>ty_attrs
+        VALUE(rs_attrs)    TYPE zif_oassh_sftp_one_shot=>ty_attrs
       RAISING
         zcx_oassh_error.
     METHODS sftp_mutation
@@ -356,6 +335,232 @@ ENDCLASS.
 CLASS zcl_oassh IMPLEMENTATION.
 
 
+  METHOD zif_oassh_interactive_exec~exec_open.
+    exec_open(
+      iv_command         = iv_command
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_interactive_exec~exec_write.
+    exec_write( iv_data ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_interactive_exec~exec_read.
+    rv_data = exec_read( iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_interactive_exec~exec_eof.
+    exec_eof( ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_interactive_exec~exec_close.
+    exec_close( iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_interactive_exec~exec_is_closed.
+    rv_closed = exec_is_closed( ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_interactive_exec~get_stderr.
+    rv_output = get_stderr( ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_interactive_exec~get_exit_status.
+    rv_status = get_exit_status( ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_interactive_exec~get_disconnect_reason.
+    rv_reason = get_disconnect_reason( ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_interactive_exec~close.
+    close( ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_one_shot~sftp_download.
+    rv_data = sftp_download(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_one_shot~sftp_upload.
+    sftp_upload(
+      iv_path            = iv_path
+      iv_data            = iv_data
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_one_shot~sftp_stat.
+    rs_attrs = sftp_stat(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_one_shot~sftp_lstat.
+    rs_attrs = sftp_lstat(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_one_shot~sftp_list.
+    rt_names = sftp_list(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_one_shot~sftp_mkdir.
+    sftp_mkdir(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_one_shot~sftp_rmdir.
+    sftp_rmdir(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_one_shot~sftp_remove.
+    sftp_remove(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_one_shot~sftp_rename.
+    sftp_rename(
+      iv_old_path        = iv_old_path
+      iv_new_path        = iv_new_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_one_shot~sftp_realpath.
+    rs_name = sftp_realpath(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_one_shot~get_disconnect_reason.
+    rv_reason = get_disconnect_reason( ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_one_shot~close.
+    close( ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~sftp_open.
+    sftp_open( iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~sftp_close.
+    sftp_close( iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~sftp_download.
+    rv_data = sftp_download(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~sftp_upload.
+    sftp_upload(
+      iv_path            = iv_path
+      iv_data            = iv_data
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~sftp_stat.
+    rs_attrs = sftp_stat(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~sftp_lstat.
+    rs_attrs = sftp_lstat(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~sftp_list.
+    rt_names = sftp_list(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~sftp_mkdir.
+    sftp_mkdir(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~sftp_rmdir.
+    sftp_rmdir(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~sftp_remove.
+    sftp_remove(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~sftp_rename.
+    sftp_rename(
+      iv_old_path        = iv_old_path
+      iv_new_path        = iv_new_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~sftp_realpath.
+    rs_name = sftp_realpath(
+      iv_path            = iv_path
+      iv_timeout_seconds = iv_timeout_seconds ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~get_disconnect_reason.
+    rv_reason = get_disconnect_reason( ).
+  ENDMETHOD.
+
+
+  METHOD zif_oassh_sftp_session~close.
+    close( ).
+  ENDMETHOD.
+
+
   METHOD connect.
 
     DATA li_socket TYPE REF TO zif_oassh_socket.
diff --git a/src/zcl_oassh.clas.testclasses.abap b/src/zcl_oassh.clas.testclasses.abap
index 8cf79c2..5eb83df 100644
--- a/src/zcl_oassh.clas.testclasses.abap
+++ b/src/zcl_oassh.clas.testclasses.abap
@@ -33,6 +33,7 @@ CLASS ltcl_test DEFINITION FOR TESTING DURATION SHORT RISK LEVEL HARMLESS FINAL.
     METHODS exec_stream_guards FOR TESTING RAISING cx_static_check.
     METHODS sftp_session_dispatch FOR TESTING RAISING cx_static_check.
     METHODS sftp_session_guards FOR TESTING RAISING cx_static_check.
+    METHODS workflow_interfaces FOR TESTING RAISING cx_static_check.
     METHODS sftp_api_state FOR TESTING RAISING cx_static_check.
     METHODS empty_command_state FOR TESTING RAISING cx_static_check.
     METHODS execute_early_failure FOR TESTING RAISING cx_static_check.
@@ -99,6 +100,47 @@ ENDCLASS.
 
 CLASS ltcl_test IMPLEMENTATION.
 
+  METHOD workflow_interfaces.
+    DATA li_exec TYPE REF TO zif_oassh_interactive_exec.
+    DATA li_one_shot TYPE REF TO zif_oassh_sftp_one_shot.
+    DATA li_session TYPE REF TO zif_oassh_sftp_session.
+    DATA lx_error TYPE REF TO zcx_oassh_error.
+
+    li_exec = build_ssh( ).
+    TRY.
+        li_exec->exec_open(
+          iv_command         = 'true'
+          iv_timeout_seconds = 0 ).
+        cl_abap_unit_assert=>fail( 'interactive interface did not delegate' ).
+      CATCH zcx_oassh_error INTO lx_error.
+        cl_abap_unit_assert=>assert_equals(
+          act = lx_error->if_t100_message~t100key-msgno
+          exp = '001' ).
+    ENDTRY.
+
+    li_one_shot = build_ssh( ).
+    TRY.
+        li_one_shot->sftp_download(
+          iv_path            = '/tmp/file'
+          iv_timeout_seconds = 0 ).
+        cl_abap_unit_assert=>fail( 'one-shot interface did not delegate' ).
+      CATCH zcx_oassh_error INTO lx_error.
+        cl_abap_unit_assert=>assert_equals(
+          act = lx_error->if_t100_message~t100key-msgno
+          exp = '001' ).
+    ENDTRY.
+
+    li_session = build_ssh( ).
+    TRY.
+        li_session->sftp_open( 0 ).
+        cl_abap_unit_assert=>fail( 'session interface did not delegate' ).
+      CATCH zcx_oassh_error INTO lx_error.
+        cl_abap_unit_assert=>assert_equals(
+          act = lx_error->if_t100_message~t100key-msgno
+          exp = '001' ).
+    ENDTRY.
+  ENDMETHOD.
+
   METHOD close_clears_secrets.
     DATA lo_ssh TYPE REF TO zcl_oassh.
     lo_ssh = build_ssh( ).
@@ -888,7 +930,7 @@ CLASS ltcl_test IMPLEMENTATION.
     DATA lv_inbound_a TYPE xstring.
     DATA lv_inbound_b TYPE xstring.
     DATA lv_inbound TYPE xstring.
-    DATA lt_names TYPE zcl_oassh_sftp=>ty_names.
+    DATA lt_names TYPE zif_oassh_sftp_one_shot=>ty_names.
 
     lo_mock = NEW #( ).
     li_socket = lo_mock.
@@ -936,7 +978,7 @@ CLASS ltcl_test IMPLEMENTATION.
     DATA li_socket TYPE REF TO zif_oassh_socket.
     DATA li_random TYPE REF TO zif_oassh_random.
     DATA li_verifier TYPE REF TO zif_oassh_host_verifier.
-    DATA ls_attrs TYPE zcl_oassh_sftp=>ty_attrs.
+    DATA ls_attrs TYPE zif_oassh_sftp_one_shot=>ty_attrs.
 
     lo_mock = NEW #( ).
     li_socket = lo_mock.
@@ -2194,9 +2236,9 @@ CLASS ltcl_test IMPLEMENTATION.
     DATA li_socket TYPE REF TO zif_oassh_socket.
     DATA li_random TYPE REF TO zif_oassh_random.
     DATA li_verifier TYPE REF TO zif_oassh_host_verifier.
-    DATA lt_names TYPE zcl_oassh_sftp=>ty_names.
+    DATA lt_names TYPE zif_oassh_sftp_one_shot=>ty_names.
     DATA lv_data TYPE xstring.
-    DATA ls_attrs TYPE zcl_oassh_sftp=>ty_attrs.
+    DATA ls_attrs TYPE zif_oassh_sftp_one_shot=>ty_attrs.
 
     lo_mock = NEW #( ).
     li_socket = lo_mock.
diff --git a/src/zcl_oassh_sftp.clas.abap b/src/zcl_oassh_sftp.clas.abap
index 3f4d19d..38fb26c 100644
--- a/src/zcl_oassh_sftp.clas.abap
+++ b/src/zcl_oassh_sftp.clas.abap
@@ -4,36 +4,6 @@ CLASS zcl_oassh_sftp DEFINITION
   CREATE PUBLIC.
 
   PUBLIC SECTION.
-    TYPES ty_uint32 TYPE x LENGTH 4.
-    TYPES ty_uint64 TYPE x LENGTH 8.
-    TYPES:
-      BEGIN OF ty_extension,
-        extension_type TYPE xstring,
-        extension_data TYPE xstring,
-      END OF ty_extension.
-    TYPES ty_extensions TYPE STANDARD TABLE OF ty_extension WITH EMPTY KEY.
-    TYPES:
-      BEGIN OF ty_attrs,
-        flags           TYPE ty_uint32,
-        has_size        TYPE abap_bool,
-        size            TYPE ty_uint64,
-        has_uid_gid     TYPE abap_bool,
-        uid             TYPE ty_uint32,
-        gid             TYPE ty_uint32,
-        has_permissions TYPE abap_bool,
-        permissions     TYPE ty_uint32,
-        has_acmodtime   TYPE abap_bool,
-        atime           TYPE ty_uint32,
-        mtime           TYPE ty_uint32,
-        extensions      TYPE ty_extensions,
-      END OF ty_attrs.
-    TYPES:
-      BEGIN OF ty_name,
-        filename TYPE xstring,
-        longname TYPE xstring,
-        attrs    TYPE ty_attrs,
-      END OF ty_name.
-    TYPES ty_names TYPE STANDARD TABLE OF ty_name WITH EMPTY KEY.
     CONSTANTS c_max_packet_length TYPE i VALUE 262144.
     CONSTANTS:
       BEGIN OF c_state,
@@ -134,12 +104,12 @@ CLASS zcl_oassh_sftp DEFINITION
         VALUE(rv_status) TYPE i.
     METHODS get_attrs
       RETURNING
-        VALUE(rs_attrs) TYPE ty_attrs.
+        VALUE(rs_attrs) TYPE zif_oassh_sftp_one_shot=>ty_attrs.
     METHODS get_names
       RETURNING
-        VALUE(rt_names) TYPE ty_names.
+        VALUE(rt_names) TYPE zif_oassh_sftp_one_shot=>ty_names.
     METHODS get_realpath
-      RETURNING VALUE(rs_name) TYPE ty_name.
+      RETURNING VALUE(rs_name) TYPE zif_oassh_sftp_one_shot=>ty_name.
 
   PRIVATE SECTION.
     TYPES ty_request_ids TYPE SORTED TABLE OF i WITH UNIQUE KEY table_line.
@@ -177,9 +147,9 @@ CLASS zcl_oassh_sftp DEFINITION
     DATA mv_upload_data TYPE xstring.
     DATA mv_upload_position TYPE i.
     DATA mv_write_length TYPE i.
-    DATA ms_attrs TYPE ty_attrs.
-    DATA mt_names TYPE ty_names.
-    DATA ms_realpath TYPE ty_name.
+    DATA ms_attrs TYPE zif_oassh_sftp_one_shot=>ty_attrs.
+    DATA mt_names TYPE zif_oassh_sftp_one_shot=>ty_names.
+    DATA ms_realpath TYPE zif_oassh_sftp_one_shot=>ty_name.
 
     METHODS frame
       IMPORTING
@@ -313,12 +283,12 @@ CLASS zcl_oassh_sftp DEFINITION
         io_packet           TYPE REF TO zcl_oassh_stream
         iv_require_consumed TYPE abap_bool DEFAULT abap_true
       RETURNING
-        VALUE(rs_attrs)     TYPE ty_attrs
+        VALUE(rs_attrs)     TYPE zif_oassh_sftp_one_shot=>ty_attrs
       RAISING
         zcx_oassh_error.
     CLASS-METHODS flag_is_set
       IMPORTING
-        iv_flags      TYPE ty_uint32
+        iv_flags      TYPE zif_oassh_sftp_one_shot=>ty_uint32
         iv_bit        TYPE i
       RETURNING
         VALUE(rv_set) TYPE abap_bool.
@@ -1021,7 +991,7 @@ CLASS zcl_oassh_sftp IMPLEMENTATION.
     DATA lv_status TYPE i.
     DATA lv_count TYPE i.
     DATA lv_total TYPE i.
-    DATA ls_name TYPE ty_name.
+    DATA ls_name TYPE zif_oassh_sftp_one_shot=>ty_name.
     CASE mv_state.
       WHEN c_state-opendir_pending.
         CASE iv_type.
@@ -1115,11 +1085,11 @@ CLASS zcl_oassh_sftp IMPLEMENTATION.
   METHOD parse_attrs.
 * Section 5 fixes both field order and flag semantics. Unsupported v3 bits
 * are a protocol error; raw unsigned values remain byte-exact for portable ABAP.
-    DATA lv_flags TYPE ty_uint32.
+    DATA lv_flags TYPE zif_oassh_sftp_one_shot=>ty_uint32.
     DATA lv_bit_index TYPE i.
     DATA lv_bit TYPE c LENGTH 1.
     DATA lv_count TYPE i.
-    DATA ls_extension TYPE ty_extension.
+    DATA ls_extension TYPE zif_oassh_sftp_one_shot=>ty_extension.
     lv_flags = io_packet->take( 4 ).
     lv_bit_index = 2.
     WHILE lv_bit_index <= 28.
diff --git a/src/zcl_oassh_sftp.clas.testclasses.abap b/src/zcl_oassh_sftp.clas.testclasses.abap
index a11373d..0c2bd39 100644
--- a/src/zcl_oassh_sftp.clas.testclasses.abap
+++ b/src/zcl_oassh_sftp.clas.testclasses.abap
@@ -492,7 +492,7 @@ CLASS ltcl_test IMPLEMENTATION.
   METHOD stat_attrs.
 * Sections 5 and 6.8: flags determine the exact order of every ATTRS field.
     DATA lv_out TYPE xstring.
-    DATA ls_attrs TYPE zcl_oassh_sftp=>ty_attrs.
+    DATA ls_attrs TYPE zif_oassh_sftp_one_shot=>ty_attrs.
     lv_out = mo_sftp->start_stat( 'a' ).
     lv_out = mo_sftp->receive( '000000050200000003' ).
     cl_abap_unit_assert=>assert_equals(
@@ -548,7 +548,7 @@ CLASS ltcl_test IMPLEMENTATION.
   METHOD stat_extensions.
 * Unknown extension values are preserved as opaque byte strings.
     DATA lv_out TYPE xstring.
-    DATA ls_attrs TYPE zcl_oassh_sftp=>ty_attrs.
+    DATA ls_attrs TYPE zif_oassh_sftp_one_shot=>ty_attrs.
     lv_out = mo_sftp->start_stat( 'a' ).
     lv_out = mo_sftp->receive( '000000050200000003' ).
     lv_out = mo_sftp->receive( '0000002169000000018000000000000002000000016100000000000000016200000002CCCC' ).
@@ -612,7 +612,7 @@ CLASS ltcl_test IMPLEMENTATION.
   METHOD list_directory.
 * OPENDIR -> HANDLE -> repeated READDIR/NAME -> EOF -> CLOSE/OK.
     DATA lv_out TYPE xstring.
-    DATA lt_names TYPE zcl_oassh_sftp=>ty_names.
+    DATA lt_names TYPE zif_oassh_sftp_one_shot=>ty_names.
     lv_out = mo_sftp->start_list( 'd' ).
     lv_out = mo_sftp->receive( '000000050200000003' ).
     cl_abap_unit_assert=>assert_equals(
@@ -785,7 +785,7 @@ CLASS ltcl_test IMPLEMENTATION.
 
   METHOD realpath_name.
     DATA lv_out TYPE xstring.
-    DATA ls_name TYPE zcl_oassh_sftp=>ty_name.
+    DATA ls_name TYPE zif_oassh_sftp_one_shot=>ty_name.
     lv_out = mo_sftp->start_realpath( '.' ).
     lv_out = mo_sftp->receive( '000000050200000003' ).
     cl_abap_unit_assert=>assert_equals(
diff --git a/src/zif_oassh_interactive_exec.intf.abap b/src/zif_oassh_interactive_exec.intf.abap
new file mode 100644
index 0000000..e9a4567
--- /dev/null
+++ b/src/zif_oassh_interactive_exec.intf.abap
@@ -0,0 +1,46 @@
+INTERFACE zif_oassh_interactive_exec
+  PUBLIC.
+
+* Interactive command channel. Call exec_open( ) once, exchange binary data
+* with exec_write( ) and exec_read( ), then finish with exec_close( ). close( )
+* closes the underlying SSH socket and remains the final cleanup operation.
+  METHODS exec_open
+    IMPORTING
+      iv_command         TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING
+      zcx_oassh_error.
+  METHODS exec_write
+    IMPORTING
+      iv_data TYPE xstring
+    RAISING
+      zcx_oassh_error.
+  METHODS exec_read
+    IMPORTING
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RETURNING
+      VALUE(rv_data)     TYPE xstring
+    RAISING
+      zcx_oassh_error.
+  METHODS exec_eof
+    RAISING
+      zcx_oassh_error.
+  METHODS exec_close
+    IMPORTING
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING
+      zcx_oassh_error.
+  METHODS exec_is_closed
+    RETURNING
+      VALUE(rv_closed) TYPE abap_bool.
+  METHODS get_stderr
+    RETURNING
+      VALUE(rv_output) TYPE string.
+  METHODS get_exit_status
+    RETURNING
+      VALUE(rv_status) TYPE i.
+  METHODS get_disconnect_reason
+    RETURNING
+      VALUE(rv_reason) TYPE i.
+  METHODS close.
+ENDINTERFACE.
diff --git a/src/zif_oassh_interactive_exec.intf.xml b/src/zif_oassh_interactive_exec.intf.xml
new file mode 100644
index 0000000..f4e1346
--- /dev/null
+++ b/src/zif_oassh_interactive_exec.intf.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<abapGit version="v1.0.0" serializer="LCL_OBJECT_INTF" serializer_version="v1.0.0">
+ <asx:abap xmlns:asx="http://www.sap.com/abapxml" version="1.0">
+  <asx:values>
+   <VSEOINTERF>
+    <CLSNAME>ZIF_OASSH_INTERACTIVE_EXEC</CLSNAME>
+    <LANGU>E</LANGU>
+    <DESCRIPT>open-abap-ssh - Interactive exec</DESCRIPT>
+    <EXPOSURE>2</EXPOSURE>
+    <STATE>1</STATE>
+    <UNICODE>X</UNICODE>
+   </VSEOINTERF>
+  </asx:values>
+ </asx:abap>
+</abapGit>
diff --git a/src/zif_oassh_sftp_one_shot.intf.abap b/src/zif_oassh_sftp_one_shot.intf.abap
new file mode 100644
index 0000000..8cad535
--- /dev/null
+++ b/src/zif_oassh_sftp_one_shot.intf.abap
@@ -0,0 +1,106 @@
+INTERFACE zif_oassh_sftp_one_shot
+  PUBLIC.
+
+* One SFTP operation per SSH connection. Each sftp_* method owns the SFTP
+* channel lifecycle. Call close( ) afterwards to close the underlying socket.
+  TYPES ty_uint32 TYPE x LENGTH 4.
+  TYPES ty_uint64 TYPE x LENGTH 8.
+  TYPES:
+    BEGIN OF ty_extension,
+      extension_type TYPE xstring,
+      extension_data TYPE xstring,
+    END OF ty_extension.
+  TYPES ty_extensions TYPE STANDARD TABLE OF ty_extension WITH EMPTY KEY.
+  TYPES:
+    BEGIN OF ty_attrs,
+      flags           TYPE ty_uint32,
+      has_size        TYPE abap_bool,
+      size            TYPE ty_uint64,
+      has_uid_gid     TYPE abap_bool,
+      uid             TYPE ty_uint32,
+      gid             TYPE ty_uint32,
+      has_permissions TYPE abap_bool,
+      permissions     TYPE ty_uint32,
+      has_acmodtime   TYPE abap_bool,
+      atime           TYPE ty_uint32,
+      mtime           TYPE ty_uint32,
+      extensions      TYPE ty_extensions,
+    END OF ty_attrs.
+  TYPES:
+    BEGIN OF ty_name,
+      filename TYPE xstring,
+      longname TYPE xstring,
+      attrs    TYPE ty_attrs,
+    END OF ty_name.
+  TYPES ty_names TYPE STANDARD TABLE OF ty_name WITH EMPTY KEY.
+  METHODS sftp_download
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RETURNING
+      VALUE(rv_data)     TYPE xstring
+    RAISING
+      zcx_oassh_error.
+  METHODS sftp_upload
+    IMPORTING
+      iv_path            TYPE string
+      iv_data            TYPE xstring
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING
+      zcx_oassh_error.
+  METHODS sftp_stat
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RETURNING
+      VALUE(rs_attrs)    TYPE ty_attrs
+    RAISING
+      zcx_oassh_error.
+  METHODS sftp_lstat
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RETURNING
+      VALUE(rs_attrs)    TYPE ty_attrs
+    RAISING
+      zcx_oassh_error.
+  METHODS sftp_list
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RETURNING
+      VALUE(rt_names)    TYPE ty_names
+    RAISING
+      zcx_oassh_error.
+  METHODS sftp_mkdir
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING zcx_oassh_error.
+  METHODS sftp_rmdir
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING zcx_oassh_error.
+  METHODS sftp_remove
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING zcx_oassh_error.
+  METHODS sftp_rename
+    IMPORTING
+      iv_old_path        TYPE string
+      iv_new_path        TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING zcx_oassh_error.
+  METHODS sftp_realpath
+    IMPORTING
+      iv_path                TYPE string
+      iv_timeout_seconds     TYPE i DEFAULT 300
+    RETURNING VALUE(rs_name) TYPE ty_name
+    RAISING zcx_oassh_error.
+  METHODS get_disconnect_reason
+    RETURNING
+      VALUE(rv_reason) TYPE i.
+  METHODS close.
+ENDINTERFACE.
diff --git a/src/zif_oassh_sftp_one_shot.intf.xml b/src/zif_oassh_sftp_one_shot.intf.xml
new file mode 100644
index 0000000..d3c76a8
--- /dev/null
+++ b/src/zif_oassh_sftp_one_shot.intf.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<abapGit version="v1.0.0" serializer="LCL_OBJECT_INTF" serializer_version="v1.0.0">
+ <asx:abap xmlns:asx="http://www.sap.com/abapxml" version="1.0">
+  <asx:values>
+   <VSEOINTERF>
+    <CLSNAME>ZIF_OASSH_SFTP_ONE_SHOT</CLSNAME>
+    <LANGU>E</LANGU>
+    <DESCRIPT>open-abap-ssh - One-shot SFTP</DESCRIPT>
+    <EXPOSURE>2</EXPOSURE>
+    <STATE>1</STATE>
+    <UNICODE>X</UNICODE>
+   </VSEOINTERF>
+  </asx:values>
+ </asx:abap>
+</abapGit>
diff --git a/src/zif_oassh_sftp_session.intf.abap b/src/zif_oassh_sftp_session.intf.abap
new file mode 100644
index 0000000..65b93f7
--- /dev/null
+++ b/src/zif_oassh_sftp_session.intf.abap
@@ -0,0 +1,87 @@
+INTERFACE zif_oassh_sftp_session
+  PUBLIC.
+
+* Reusable SFTP channel. Call sftp_open( ) once, run sequential sftp_*
+* operations, then call sftp_close( ) and close( ). Result types are owned by
+* zif_oassh_sftp_one_shot and referenced directly by both SFTP contracts.
+  METHODS sftp_open
+    IMPORTING
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING
+      zcx_oassh_error.
+  METHODS sftp_close
+    IMPORTING
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING
+      zcx_oassh_error.
+  METHODS sftp_download
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RETURNING
+      VALUE(rv_data)     TYPE xstring
+    RAISING
+      zcx_oassh_error.
+  METHODS sftp_upload
+    IMPORTING
+      iv_path            TYPE string
+      iv_data            TYPE xstring
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING
+      zcx_oassh_error.
+  METHODS sftp_stat
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RETURNING
+      VALUE(rs_attrs)    TYPE zif_oassh_sftp_one_shot=>ty_attrs
+    RAISING
+      zcx_oassh_error.
+  METHODS sftp_lstat
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RETURNING
+      VALUE(rs_attrs)    TYPE zif_oassh_sftp_one_shot=>ty_attrs
+    RAISING
+      zcx_oassh_error.
+  METHODS sftp_list
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RETURNING
+      VALUE(rt_names)    TYPE zif_oassh_sftp_one_shot=>ty_names
+    RAISING
+      zcx_oassh_error.
+  METHODS sftp_mkdir
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING zcx_oassh_error.
+  METHODS sftp_rmdir
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING zcx_oassh_error.
+  METHODS sftp_remove
+    IMPORTING
+      iv_path            TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING zcx_oassh_error.
+  METHODS sftp_rename
+    IMPORTING
+      iv_old_path        TYPE string
+      iv_new_path        TYPE string
+      iv_timeout_seconds TYPE i DEFAULT 300
+    RAISING zcx_oassh_error.
+  METHODS sftp_realpath
+    IMPORTING
+      iv_path                TYPE string
+      iv_timeout_seconds     TYPE i DEFAULT 300
+    RETURNING VALUE(rs_name) TYPE zif_oassh_sftp_one_shot=>ty_name
+    RAISING zcx_oassh_error.
+  METHODS get_disconnect_reason
+    RETURNING
+      VALUE(rv_reason) TYPE i.
+  METHODS close.
+ENDINTERFACE.
diff --git a/src/zif_oassh_sftp_session.intf.xml b/src/zif_oassh_sftp_session.intf.xml
new file mode 100644
index 0000000..ddd0fbf
--- /dev/null
+++ b/src/zif_oassh_sftp_session.intf.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<abapGit version="v1.0.0" serializer="LCL_OBJECT_INTF" serializer_version="v1.0.0">
+ <asx:abap xmlns:asx="http://www.sap.com/abapxml" version="1.0">
+  <asx:values>
+   <VSEOINTERF>
+    <CLSNAME>ZIF_OASSH_SFTP_SESSION</CLSNAME>
+    <LANGU>E</LANGU>
+    <DESCRIPT>open-abap-ssh - Reusable SFTP</DESCRIPT>
+    <EXPOSURE>2</EXPOSURE>
+    <STATE>1</STATE>
+    <UNICODE>X</UNICODE>
+   </VSEOINTERF>
+  </asx:values>
+ </asx:abap>
+</abapGit>