diff --git a/package-firewall/bash/generate.sh b/package-firewall/bash/generate.sh
index e704b2a..ec5cd66 100755
--- a/package-firewall/bash/generate.sh
+++ b/package-firewall/bash/generate.sh
@@ -45,24 +45,28 @@ SHARED_BLOCKS_DIR="$SCRIPT_DIR/../shared/blocks"
 : "${ENDOR_API_KEY_ID:?ENDOR_API_KEY_ID is required}"
 : "${ENDOR_API_SECRET:?ENDOR_API_SECRET is required}"
 
+# Reject credential characters that would corrupt generated scripts/URLs.
+case "${ENDOR_API_KEY_ID}${ENDOR_API_SECRET}" in
+  *[!A-Za-z0-9+/=_.-]*)
+    echo "ERROR: ENDOR_API_KEY_ID / ENDOR_API_SECRET contain unsupported characters" >&2
+    exit 1 ;;
+esac
+
 # ─── Resolve FQDN ─────────────────────────────────────────────────────────────
 FQDN="${ENDOR_FQDN:-https://factory.endorlabs.com}"
 
 # ─── Compute derived values ────────────────────────────────────────────────────
+# Only machine-independent values are derived here. Attribution values
+# (<console-user>@<machine>) are computed at install time — see credentials_block.
 FQDN_HOST="${FQDN#https://}"
 FQDN_HOST="${FQDN_HOST#http://}"
 TRUSTED_HOST="${FQDN_HOST%%:*}"
 
 NPM_REGISTRY_URL="${FQDN}/v1/namespaces/${ENDOR_NAMESPACE}/firewall/npm/"
 NPM_REGISTRY_HOST="${FQDN_HOST}/v1/namespaces/${ENDOR_NAMESPACE}/firewall/npm/"
-NPM_AUTH_B64=$(printf '%s' "${ENDOR_API_KEY_ID}:${ENDOR_API_SECRET}" | base64 | tr -d '\n')
-API_SECRET_B64=$(printf '%s' "${ENDOR_API_SECRET}" | base64 | tr -d '\n')
-
 PYPI_URL="${FQDN}/v1/namespaces/${ENDOR_NAMESPACE}/firewall/pypi/simple/"
-PIP_INDEX_URL="https://${ENDOR_API_KEY_ID}:${ENDOR_API_SECRET}@${FQDN_HOST}/v1/namespaces/${ENDOR_NAMESPACE}/firewall/pypi/simple/"
-
-GO_PROXY_URL="https://${ENDOR_API_KEY_ID}:${ENDOR_API_SECRET}@${FQDN_HOST}/v1/namespaces/${ENDOR_NAMESPACE}/firewall/go/,direct"
 MAVEN_REGISTRY_URL="${FQDN}/v1/namespaces/${ENDOR_NAMESPACE}/firewall/maven/"
+API_SECRET_B64=$(printf '%s' "${ENDOR_API_SECRET}" | base64 | tr -d '\n')
 
 # ─── Output directory ─────────────────────────────────────────────────────────
 OUT_DIR="${SCRIPT_DIR}/out/${ENDOR_NAMESPACE}"
@@ -74,16 +78,13 @@ substitute() {
     -e "s|{{NAMESPACE}}|${ENDOR_NAMESPACE}|g" \
     -e "s|{{API_KEY_ID}}|${ENDOR_API_KEY_ID}|g" \
     -e "s|{{API_SECRET}}|${ENDOR_API_SECRET}|g" \
+    -e "s|{{API_SECRET_B64}}|${API_SECRET_B64}|g" \
     -e "s|{{FQDN}}|${FQDN}|g" \
+    -e "s|{{FQDN_HOST}}|${FQDN_HOST}|g" \
     -e "s|{{NPM_REGISTRY_URL}}|${NPM_REGISTRY_URL}|g" \
     -e "s|{{NPM_REGISTRY_HOST}}|${NPM_REGISTRY_HOST}|g" \
-    -e "s|{{NPM_AUTH_B64}}|${NPM_AUTH_B64}|g" \
-    -e "s|{{API_SECRET_B64}}|${API_SECRET_B64}|g" \
     -e "s|{{PYPI_URL}}|${PYPI_URL}|g" \
-    -e "s|{{PIP_INDEX_URL}}|${PIP_INDEX_URL}|g" \
-    -e "s|{{ENDOR_PYPI_URL}}|${PIP_INDEX_URL}|g" \
     -e "s|{{TRUSTED_HOST}}|${TRUSTED_HOST}|g" \
-    -e "s|{{GO_PROXY_URL}}|${GO_PROXY_URL}|g" \
     -e "s|{{MAVEN_REGISTRY_URL}}|${MAVEN_REGISTRY_URL}|g"
 }
 
@@ -108,10 +109,8 @@ emit_block_assignment() {
   echo ")"
 }
 
-# emit_all_blocks
-# Emits all block variable assignments into the generated script.
-# Edit shared/blocks/*.txt to change shared config content.
-# Edit templates/envsh.txt to change the bash-only env var block.
+# emit_all_blocks — emits all block variable assignments into the generated
+# script. Attribution {{...}} tokens are filled at install time by the templates.
 emit_all_blocks() {
   echo "# ── Block content (from shared/blocks/) ─────────────────────────────────────"
   emit_block_assignment "ENVSH_BLOCK"         "$SHARED_BLOCKS_DIR/envsh.txt"
@@ -162,6 +161,30 @@ USER_GROUP=$(id -gn "$CONSOLE_USER" 2>/dev/null || echo "staff")
 USERBLOCK
 }
 
+# credentials_block — attribution values computed on the dev machine at install
+# time (the <console-user>@<machine> label doesn't exist at generation time).
+credentials_block() {
+  substitute << 'CREDBLOCK'
+# ── User attribution (computed at install time) ───────────────────────────────
+ENDOR_API_KEY_ID='{{API_KEY_ID}}'
+ENDOR_API_SECRET='{{API_SECRET}}'
+
+ENDOR_ATTR_LABEL="${CONSOLE_USER}@$(endor_host_label)"
+ENDOR_ATTR_USER="$(endor_attr_username "$ENDOR_ATTR_LABEL" "$ENDOR_API_KEY_ID")"
+
+# npm _auth = base64(username:password)
+ENDOR_AUTH_B64="$(printf '%s:%s' "$ENDOR_ATTR_USER" "$ENDOR_API_SECRET" | endor_b64)"
+
+# pip / uv / go URLs: percent-encode both userinfo halves ('/' would break the URL).
+ENDOR_PYPI_URL="https://$(endor_urlenc_b64 "$ENDOR_ATTR_USER"):$(endor_urlenc_b64 "$ENDOR_API_SECRET")@{{FQDN_HOST}}/v1/namespaces/{{NAMESPACE}}/firewall/pypi/simple/"
+ENDOR_GO_PROXY_URL="https://$(endor_urlenc_b64 "$ENDOR_ATTR_USER"):$(endor_urlenc_b64 "$ENDOR_API_SECRET")@{{FQDN_HOST}}/v1/namespaces/{{NAMESPACE}}/firewall/go/,direct"
+
+# No exports — every consumer is same-process template code inlined below.
+
+echo "[endor] user attribution → ${ENDOR_ATTR_LABEL}"
+CREDBLOCK
+}
+
 # script_header <output> <description>
 script_header() {
   local output="$1"
@@ -192,6 +215,8 @@ build_script() {
 
   {
     script_header "$output" "$description"
+    credentials_block
+    echo ""
     emit_all_blocks
     echo "# ════════════════════════════════════════════════════════════════════════════"
     echo "# Env setup"
@@ -247,6 +272,8 @@ build_remove_script "$OUT_DIR/endor-remove.sh"
 {
   script_header "$OUT_DIR/endor-all.sh" \
     "Configures all package managers for Endor Package Firewall. Covers: npm · pnpm · yarn classic · yarn 2+ · bun · pip · uv · poetry · go · maven"
+  credentials_block
+  echo ""
   emit_all_blocks
   echo "# ════════════════════════════════════════════════════════════════════════════"
   echo "# Env setup"
@@ -295,7 +322,7 @@ echo "   All scripts accept --dry-run to preview changes without writing anythin
 echo "   Upload to your MDM tool. Each script is self-contained and idempotent."
 echo ""
 echo "   To customise: edit shared/blocks/*.txt (shared config content)"
-echo "                 or templates/envsh.txt (bash env var block)"
+echo "                 or shared/blocks/envsh.txt (bash env var block)"
 echo "                 or templates/*.sh (orchestration logic)"
 echo ""
 echo "   Re-running overwrites the same output directory."
diff --git a/package-firewall/bash/lib/common.sh b/package-firewall/bash/lib/common.sh
index 4268106..c518ee2 100644
--- a/package-firewall/bash/lib/common.sh
+++ b/package-firewall/bash/lib/common.sh
@@ -7,9 +7,11 @@
 #   resolve_user_home       <user>             — resolves home via dscl / getent / POSIX
 #   upsert_block            <file> <content> <owner> <group>
 #                                              — non-destructive, idempotent sentinel-block writer
+#                                                merges into an existing [global] for pip.conf
 #                                                honours DRY_RUN=1 (prints intent, no writes)
 #   remove_block            <file> <owner> <group>
-#                                              — strips Endor sentinel block from a file
+#                                              — strips Endor sentinel block from a file,
+#                                                restores keys disabled with '#endor-bak#'
 #                                                honours DRY_RUN=1 (prints intent, no writes)
 #   warn_if_key_conflict    <file> <pattern> <label>
 #                                              — warns when a key exists outside an Endor block
@@ -24,6 +26,38 @@ ENDOR_BLOCK_END="# ===== END ENDOR PACKAGE FIREWALL ====="
 ENDOR_XML_BLOCK_START="<!-- ===== BEGIN ENDOR PACKAGE FIREWALL (managed — do not edit) ===== -->"
 ENDOR_XML_BLOCK_END="<!-- ===== END ENDOR PACKAGE FIREWALL ===== -->"
 
+# ── User attribution helpers ──────────────────────────────────────────────────
+# Encode <console-user>@<machine> into the Basic-auth username. The firewall
+# decodes the label, auths with the real API key, and logs it as "User".
+
+# endor_b64 — portable base64, no line wrapping (GNU wraps at 76 cols; BSD doesn't).
+endor_b64() {
+  if base64 --help 2>&1 | grep -q -- '-w'; then
+    base64 -w0
+  else
+    base64 | tr -d '\n'
+  fi
+}
+
+# endor_urlenc_b64 <b64> — percent-encode base64 chars (+ / =) for URL userinfo.
+endor_urlenc_b64() {
+  printf '%s' "$1" | sed -e 's/+/%2B/g' -e 's#/#%2F#g' -e 's/=/%3D/g'
+}
+
+# endor_host_label — a stable, human-readable machine name for attribution.
+endor_host_label() {
+  scutil --get ComputerName 2>/dev/null || hostname 2>/dev/null || echo unknown
+}
+
+# endor_attr_username <label> <api_key_id>
+# Returns base64(base64("userattr:"+label)+":"+keyId) — the format
+# decodeAttributedUsername() expects in endorfactory's auth layer.
+endor_attr_username() {
+  local label="$1" key_id="$2" inner
+  inner=$(printf '%s' "userattr:${label}" | endor_b64)
+  printf '%s:%s' "$inner" "$key_id" | endor_b64
+}
+
 # detect_console_user
 # MDM tools (Kandji, Jamf) run scripts as root. $HOME resolves to /var/root, which
 # is not where developer config files live. Returns the name of the actual logged-in
@@ -76,20 +110,46 @@ resolve_user_home() {
 #   - File present, no block → appends the block; existing content untouched
 #   - File present, block found → replaces only the block; rest untouched
 #   - DRY_RUN=1            → prints what would happen, writes nothing
+#
+# pip.conf special case: pip rejects duplicate [global] sections, so when both
+# <content> and the file declare [global], the keys are merged into the existing
+# section and conflicting keys are disabled reversibly with '#endor-bak#'.
 upsert_block() {
   local file="$1"
   local content="$2"
   local owner="$3"
   local group="$4"
+  local tmp merge=0
+
+  # Strip CRLF (block files are shared with the Windows generator).
+  content=${content//$'\r'/}
+
+  # Merge only when both the content and the pre-existing file declare [global]
+  if printf '%s\n' "$content" | grep -q '^\[global\]$' \
+     && [[ -f "$file" ]] \
+     && awk -v start="$ENDOR_BLOCK_START" -v end="$ENDOR_BLOCK_END" '
+          index($0, start) { skip=1; next }
+          index($0, end)   { skip=0; next }
+          !skip && /^\[global\]/ { found=1 }
+          END { exit !found }
+        ' "$file" 2>/dev/null; then
+    merge=1
+  fi
 
   if [[ "${DRY_RUN:-0}" == "1" ]]; then
     if [[ -f "$file" ]] && grep -qF "$ENDOR_BLOCK_START" "$file" 2>/dev/null; then
       echo "[dry-run]   action : REPLACE existing Endor block"
+    elif [[ "$merge" -eq 1 ]]; then
+      echo "[dry-run]   action : MERGE into existing [global] (conflicting keys disabled via #endor-bak#)"
     elif [[ -f "$file" ]]; then
       echo "[dry-run]   action : APPEND Endor block to existing file"
     else
       echo "[dry-run]   action : CREATE file with Endor block"
     fi
+    if [[ "$merge" -eq 1 ]]; then
+      echo "[dry-run]   note   : pre-existing index keys will be disabled via '#endor-bak#'"
+      echo "[dry-run]            and the Endor keys merged into the existing [global]"
+    fi
     echo "[dry-run]   file   : $file"
     echo "[dry-run]   content:"
     echo "$content" | sed 's/^/[dry-run]     /'
@@ -101,7 +161,6 @@ upsert_block() {
 
   # Strip any existing Endor block, preserving everything else
   if [[ -f "$file" ]] && grep -qF "$ENDOR_BLOCK_START" "$file" 2>/dev/null; then
-    local tmp
     tmp=$(mktemp)
     awk -v start="$ENDOR_BLOCK_START" -v end="$ENDOR_BLOCK_END" '
       index($0, start) { skip=1; next }
@@ -111,10 +170,51 @@ upsert_block() {
     mv "$tmp" "$file"
   fi
 
-  printf '\n%s\n%s\n%s\n' \
-    "$ENDOR_BLOCK_START" \
-    "$content" \
-    "$ENDOR_BLOCK_END" >> "$file"
+  if [[ "$merge" -eq 1 ]]; then
+    # Disable-keys derived from the content; pip treats '-'/'_' and '='/':' alike.
+    local keys_re
+    keys_re=$(printf '%s\n' "$content" | sed -nE 's/^([A-Za-z0-9_-]+)[[:space:]]*[=:].*/\1/p' \
+              | sed 's/[-_]/[-_]/g' | paste -sd'|' -)
+
+    # 1. Reversibly disable pre-existing copies of those keys and their
+    #    indented continuation lines.
+    if [[ -n "$keys_re" ]] && grep -qE "^[[:space:]]*(${keys_re})[[:space:]]*[=:]" "$file"; then
+      tmp=$(mktemp)
+      awk -v re="^[[:space:]]*(${keys_re})[[:space:]]*[=:]" '
+        $0 ~ re                             { print "#endor-bak#" $0; cont=1; next }
+        cont && /^[[:space:]]+[^[:space:]]/ { print "#endor-bak#" $0; next }
+                                            { cont=0; print }
+      ' "$file" > "$tmp"
+      mv "$tmp" "$file"
+      echo "[endor] NOTE: existing pip index keys in ${file} disabled with '#endor-bak#' (restored on removal)"
+    fi
+
+    # 2. Insert the sentinel-wrapped keys after the first [global]
+    #    (temp file + getline: BSD awk rejects multi-line -v).
+    local keyfile
+    keyfile=$(mktemp)
+    {
+      echo "$ENDOR_BLOCK_START"
+      printf '%s\n' "$content" | grep -v '^\[global\]'
+      echo "$ENDOR_BLOCK_END"
+    } > "$keyfile"
+    tmp=$(mktemp)
+    awk -v keyfile="$keyfile" '
+      { print }
+      /^\[global\]/ && !done {
+        while ((getline line < keyfile) > 0) print line
+        close(keyfile)
+        done=1
+      }
+    ' "$file" > "$tmp"
+    mv "$tmp" "$file"
+    rm -f "$keyfile"
+  else
+    printf '\n%s\n%s\n%s\n' \
+      "$ENDOR_BLOCK_START" \
+      "$content" \
+      "$ENDOR_BLOCK_END" >> "$file"
+  fi
 
   chown "$owner:$group" "$file"
   chmod 600 "$file"
@@ -197,11 +297,11 @@ upsert_xml_block() {
 
 # remove_block <file> <owner> <group>
 #
-# Strips the Endor sentinel block from a config file.
+# Strips the Endor sentinel block and restores '#endor-bak#'-disabled keys.
 #   - File absent           → skips silently
 #   - No Endor block found  → skips with a notice
 #   - Block found           → removes block; preserves everything else
-#   - File empty after removal → deletes the file entirely
+#   - File empty after removal → deletes it (a bare [global] counts as empty)
 #   - DRY_RUN=1             → prints what would happen, writes nothing
 remove_block() {
   local file="$1"
@@ -227,11 +327,14 @@ remove_block() {
       !skip             { print }
     ' "$file" | tr -d '[:space:]')
 
-    if [[ -z "$remaining" ]]; then
+    if [[ -z "$remaining" || "$remaining" == "[global]" ]]; then
       echo "[dry-run]   action : REMOVE block → file would be empty → DELETE file"
     else
       echo "[dry-run]   action : REMOVE block, preserve remaining content"
     fi
+    if grep -qF '#endor-bak#' "$file" 2>/dev/null; then
+      echo "[dry-run]   restore: keys disabled with '#endor-bak#'"
+    fi
     echo "[dry-run]   file   : $file"
     echo ""
     return 0
@@ -243,10 +346,12 @@ remove_block() {
     index($0, start) { skip=1; next }
     index($0, end)   { skip=0; next }
     !skip             { print }
-  ' "$file" > "$tmp"
+  ' "$file" | sed -E 's/^([[:space:]]*)#endor-bak#/\1/' > "$tmp"
 
-  # Delete the file if it's effectively empty after block removal
-  if [[ -z "$(tr -d '[:space:]' < "$tmp")" ]]; then
+  # Delete if effectively empty (whitespace only, or a bare [global])
+  local remaining
+  remaining=$(tr -d '[:space:]' < "$tmp")
+  if [[ -z "$remaining" || "$remaining" == "[global]" ]]; then
     rm -f "$file" "$tmp"
     echo "[endor-remove] deleted (was empty) : $file"
   else
diff --git a/package-firewall/bash/templates/envsh.sh b/package-firewall/bash/templates/envsh.sh
index 361441c..b14da20 100644
--- a/package-firewall/bash/templates/envsh.sh
+++ b/package-firewall/bash/templates/envsh.sh
@@ -1,17 +1,27 @@
 # templates/envsh.sh
 # Writes ~/.config/endor/env.sh — the single credential source for all
-# env-var-based tools (npm, uv, yarn 2+, poetry; Go in future).
+# env-var-based tools (npm, yarn 2+, maven, poetry).
 # Then adds a one-line source directive to existing shell profiles.
 #
-# Block content is defined in templates/blocks/envsh.txt.
-# pip is intentionally excluded — pip.conf does not support env var expansion,
-# so pip credentials are written as literal values in python.sh instead.
+# Block content comes from shared/blocks/envsh.txt; attribution tokens are
+# filled at install time. Leftover {{...}} tokens warn and exit non-zero.
+# pip / uv / go don't read env.sh — their configs get baked literals instead.
 
 echo ""
 echo "[endor] ── env.sh setup ─────────────────────────────────────────────────────"
 
 ENDOR_ENV_SH="$USER_HOME/.config/endor/env.sh"
 
+# Fill the attribution-dependent tokens (values from the credentials block).
+ENVSH_BLOCK=${ENVSH_BLOCK//'{{ATTR_USER}}'/"$ENDOR_ATTR_USER"}
+ENVSH_BLOCK=${ENVSH_BLOCK//'{{NPM_AUTH_B64}}'/"$ENDOR_AUTH_B64"}
+
+if [[ "$ENVSH_BLOCK" == *'{{'* ]]; then
+  echo "[endor] WARNING: unresolved {{...}} token in env.sh block — a token in" >&2
+  echo "[endor]          shared/blocks/envsh.txt has no fill in templates/envsh.sh." >&2
+  _ENDOR_WARNED=1
+fi
+
 upsert_block \
   "$ENDOR_ENV_SH" \
   "$ENVSH_BLOCK" \
diff --git a/package-firewall/bash/templates/go.sh b/package-firewall/bash/templates/go.sh
index c1f2de1..b0edc3d 100644
--- a/package-firewall/bash/templates/go.sh
+++ b/package-firewall/bash/templates/go.sh
@@ -7,8 +7,8 @@
 #   Linux  → ~/.config/go/env  (or $XDG_CONFIG_HOME/go/env)
 #
 # Block content is defined in shared/blocks/goenv.txt.
-# {{GO_PROXY_URL}} is substituted at generation time — Go env files do not support
-# env var expansion, so credentials are baked into the GOPROXY value.
+# Go env files can't expand env vars, so the {{GO_PROXY_URL}} token is filled
+# here at install time with the attributed literal (from the credentials block).
 #
 # The go env file takes lower precedence than the GOPROXY process env var, so
 # project-level overrides (go env -w GOPROXY=... in a workspace) remain possible.
@@ -17,6 +17,9 @@
 echo ""
 echo "[endor-go] ── Go package manager ───────────────────────────────────────────"
 
+# Fill the attributed GOPROXY into the block content (go env can't expand env vars).
+GO_BLOCK=${GO_BLOCK//'{{GO_PROXY_URL}}'/"$ENDOR_GO_PROXY_URL"}
+
 # ── Resolve go env file path ──────────────────────────────────────────────────
 # Run `go env GOENV` with the user's HOME so Go's os.UserConfigDir() returns
 # the correct user-specific path (macOS: ~/Library/Application Support/go/env,
diff --git a/package-firewall/bash/templates/js.sh b/package-firewall/bash/templates/js.sh
index 4264c7d..b1b07bb 100644
--- a/package-firewall/bash/templates/js.sh
+++ b/package-firewall/bash/templates/js.sh
@@ -20,6 +20,15 @@ echo "[endor-js] ── JavaScript package managers ─────────
 
 # ── .npmrc ────────────────────────────────────────────────────────────────────
 # Covers: npm (all versions), pnpm (8.x–11.x), yarn classic (1.x), bun (all versions)
+
+# Swap to the attributed user (shared block stays Windows-safe). Needed for
+# bun: its last-write-wins .npmrc parsing would otherwise drop attribution.
+NPMRC_BLOCK=${NPMRC_BLOCK//'${ENDOR_API_KEY_ID}'/'${ENDOR_ATTR_USER}'}
+if [[ "$NPMRC_BLOCK" != *'${ENDOR_ATTR_USER}'* ]]; then
+  echo "[endor-js] WARNING: attribution swap did not match — shared/blocks/npmrc.txt changed?" >&2
+  _ENDOR_WARNED=1
+fi
+
 warn_if_key_conflict \
   "$USER_HOME/.npmrc" \
   "^registry=" \
@@ -53,8 +62,16 @@ echo "[endor-js]   covers: yarn classic (1.x)"
 # ── .yarnrc.yml ───────────────────────────────────────────────────────────────
 # Covers: yarn 2+ / berry only
 # yarn 2+ reads .yarnrc.yml for registry and auth — it does NOT read .npmrc.
-# Uses npmAuthIdent (plain "key:secret") — confirmed working with Endor firewall.
+# Uses npmAuthIdent (plain "user:secret") — confirmed working with Endor firewall.
 # Yarn berry supports ${VAR} expansion in .yarnrc.yml values (yarn 3+).
+
+# Swap to the attributed user (shared block stays Windows-safe).
+YARNRC_BLOCK=${YARNRC_BLOCK//'${ENDOR_API_KEY_ID}'/'${ENDOR_ATTR_USER}'}
+if [[ "$YARNRC_BLOCK" != *'${ENDOR_ATTR_USER}'* ]]; then
+  echo "[endor-js] WARNING: attribution swap did not match — shared/blocks/yarnrc.txt changed?" >&2
+  _ENDOR_WARNED=1
+fi
+
 warn_if_key_conflict \
   "$USER_HOME/.yarnrc.yml" \
   "^npmRegistryServer:" \
diff --git a/package-firewall/bash/templates/maven.sh b/package-firewall/bash/templates/maven.sh
index 5ad4667..717019b 100644
--- a/package-firewall/bash/templates/maven.sh
+++ b/package-firewall/bash/templates/maven.sh
@@ -6,12 +6,19 @@
 
 # Block content is defined in shared/blocks/mavensettings.txt.
 # {{MAVEN_REGISTRY_URL}} is substituted at generation time. Credentials are NOT
-# baked in -- settings.xml references ${env.ENDOR_API_KEY_ID} / ${env.ENDOR_API_SECRET},
-# which Maven expands at runtime from the env vars already provided by env.sh.
+# baked in -- settings.xml references env vars, which Maven expands at runtime
+# from the values provided by env.sh.
 
 echo ""
 echo "[endor-maven] ── Maven ────────────────────────────────────────────────────────"
 
+# Swap to the attributed user (shared block stays Windows-safe).
+MAVEN_BLOCK=${MAVEN_BLOCK//'${env.ENDOR_API_KEY_ID}'/'${env.ENDOR_ATTR_USER}'}
+if [[ "$MAVEN_BLOCK" != *'${env.ENDOR_ATTR_USER}'* ]]; then
+  echo "[endor-maven] WARNING: attribution swap did not match — shared/blocks/mavensettings.txt changed?" >&2
+  _ENDOR_WARNED=1
+fi
+
 MAVEN_SETTINGS="$USER_HOME/.m2/settings.xml"
 
 # warn if the admin already defines a mirror/server outside an Endor block --
@@ -30,5 +37,5 @@ upsert_xml_block \
 echo "[endor-maven] settings.xml     -> $MAVEN_SETTINGS"
 echo "[endor-maven]    covers: maven (all versions), and Gradle when it reads ~/.m2"
 echo "[endor-maven]    mirror: {{MAVEN_REGISTRY_URL}} (mirrorOf=*)"
-echo "[endor-maven]    NOTE: credentials come from env vars (ENDOR_API_KEY_ID/SECRET) via env.sh"
+echo "[endor-maven]    NOTE: credentials come from env vars (ENDOR_ATTR_USER/API_SECRET) via env.sh"
 echo "[endor-maven] ✓ Maven done"
\ No newline at end of file
diff --git a/package-firewall/bash/templates/python.sh b/package-firewall/bash/templates/python.sh
index f669c03..260e565 100644
--- a/package-firewall/bash/templates/python.sh
+++ b/package-firewall/bash/templates/python.sh
@@ -10,18 +10,27 @@
 # Block content is defined in templates/blocks/pipconf.txt and uvtoml.txt.
 #
 # Credential approach per tool:
-#   pip     → literal credentials in pip.conf (pip cannot expand env vars — see pipconf.txt)
-#   uv      → ${ENDOR_PYPI_URL} env var reference in uv.toml (uv expands ${VAR})
+#   pip     → literal index-url in pip.conf (pip cannot expand env vars)
+#   uv      → literal index-url in uv.toml  (baked at install time, like pip)
 #   poetry  → POETRY_HTTP_BASIC_ENDOR_FIREWALL_* env vars via env.sh (written by env.sh step)
 #
-# pip section uses [endor-firewall] named section — avoids clobbering admin's [global].
+# pip/uv index-urls carry the attributed username, so their {{...}} tokens are
+# filled here at install time (from the credentials block).
+#
+# pip block uses [global]; upsert_block merges into a pre-existing one.
 
 echo ""
 echo "[endor-python] ── Python package managers ──────────────────────────────────"
 
+# Fill the attributed index-url into the block content (pip/uv can't expand env vars).
+PIP_BLOCK=${PIP_BLOCK//'{{PIP_INDEX_URL}}'/"$ENDOR_PYPI_URL"}
+UV_BLOCK=${UV_BLOCK//'{{ENDOR_PYPI_URL}}'/"$ENDOR_PYPI_URL"}
+
 # ── pip ───────────────────────────────────────────────────────────────────────
 # pip reads pip.conf automatically from all three locations below.
 # pip does not support env var expansion — credentials are literal values (see pipconf.txt).
+# warn alerts once when existing keys get disabled, and persistently for
+# conflicts the merge can't absorb (e.g. index-url under [install]).
 for pip_conf in \
   "$USER_HOME/.pip/pip.conf" \
   "$USER_HOME/.config/pip/pip.conf" \
diff --git a/package-firewall/bash/templates/remove.sh b/package-firewall/bash/templates/remove.sh
index b4edfcd..cf1796a 100644
--- a/package-firewall/bash/templates/remove.sh
+++ b/package-firewall/bash/templates/remove.sh
@@ -66,10 +66,39 @@ remove_block "$USER_HOME/.npmrc"      "$CONSOLE_USER" "$USER_GROUP"
 remove_block "$USER_HOME/.yarnrc"     "$CONSOLE_USER" "$USER_GROUP"
 remove_block "$USER_HOME/.yarnrc.yml" "$CONSOLE_USER" "$USER_GROUP"
 
+# yarn 1.x rewrites ~/.yarnrc on its own and can copy the Endor registry
+# outside the managed block. Delete only lines that exactly match our URL —
+# they can't be anyone else's config.
+_YARNRC="$USER_HOME/.yarnrc"
+_ENDOR_YARN_LINE='registry "{{NPM_REGISTRY_URL}}"'
+if [[ -f "$_YARNRC" ]] && awk -v s="$ENDOR_BLOCK_START" -v e="$ENDOR_BLOCK_END" '
+      index($0, s) { skip=1; next }
+      index($0, e) { skip=0; next }
+      !skip        { print }
+    ' "$_YARNRC" | grep -qxF "$_ENDOR_YARN_LINE"; then
+  if [[ "${DRY_RUN:-0}" == "1" ]]; then
+    echo "[dry-run]   action : DELETE yarn-copied Endor registry line from $_YARNRC"
+  else
+    _tmp=$(mktemp)
+    grep -vxF "$_ENDOR_YARN_LINE" "$_YARNRC" | grep -vx 'always-auth true' > "$_tmp" || true
+    if [[ -z "$(tr -d '[:space:]' < "$_tmp")" ]]; then
+      rm -f "$_YARNRC" "$_tmp"
+      echo "[endor-remove] deleted (was empty) : $_YARNRC"
+    else
+      mv "$_tmp" "$_YARNRC"
+      chown "$CONSOLE_USER:$USER_GROUP" "$_YARNRC"
+      chmod 600 "$_YARNRC"
+      echo "[endor-remove] yarn-copied line removed: $_YARNRC"
+    fi
+  fi
+fi
+unset _YARNRC _ENDOR_YARN_LINE _tmp
+
 # ── Python config files ───────────────────────────────────────────────────────
 echo ""
 echo "[endor-remove] ── Python ────────────────────────────────────────────────────"
 
+# remove_block also restores pip keys disabled with '#endor-bak#' at install time
 for pip_conf in \
   "$USER_HOME/.pip/pip.conf" \
   "$USER_HOME/.config/pip/pip.conf" \
diff --git a/package-firewall/shared/blocks/envsh.txt b/package-firewall/shared/blocks/envsh.txt
index ff16ed0..5387207 100644
--- a/package-firewall/shared/blocks/envsh.txt
+++ b/package-firewall/shared/blocks/envsh.txt
@@ -1,9 +1,8 @@
 export ENDOR_API_KEY_ID="{{API_KEY_ID}}"
 export ENDOR_API_SECRET="{{API_SECRET}}"
+export ENDOR_ATTR_USER="{{ATTR_USER}}"
 export ENDOR_AUTH_B64="{{NPM_AUTH_B64}}"
 export ENDOR_API_SECRET_B64="{{API_SECRET_B64}}"
 export ENDOR_NPM_REGISTRY_URL="{{NPM_REGISTRY_URL}}"
-export ENDOR_PYPI_URL="{{PIP_INDEX_URL}}"
-export ENDOR_GO_PROXY_URL="{{GO_PROXY_URL}}"
-export POETRY_HTTP_BASIC_ENDOR_FIREWALL_USERNAME="{{API_KEY_ID}}"
-export POETRY_HTTP_BASIC_ENDOR_FIREWALL_PASSWORD="{{API_SECRET}}"
\ No newline at end of file
+export POETRY_HTTP_BASIC_ENDOR_FIREWALL_USERNAME="{{ATTR_USER}}"
+export POETRY_HTTP_BASIC_ENDOR_FIREWALL_PASSWORD="{{API_SECRET}}"