diff --git a/package-firewall/bash/generate.sh b/package-firewall/bash/generate.sh
index e704b2a..fc8b502 100755
--- a/package-firewall/bash/generate.sh
+++ b/package-firewall/bash/generate.sh
@@ -49,20 +49,17 @@ SHARED_BLOCKS_DIR="$SCRIPT_DIR/../shared/blocks"
 FQDN="${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 +71,13 @@ 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"
 }
 
@@ -111,7 +105,8 @@ emit_block_assignment() {
 # 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.
+# Attribution {{...}} tokens are not substituted here — the generated scripts
+# fill them at install time (see credentials_block).
 emit_all_blocks() {
   echo "# ── Block content (from shared/blocks/) ─────────────────────────────────────"
   emit_block_assignment "ENVSH_BLOCK"         "$SHARED_BLOCKS_DIR/envsh.txt"
@@ -162,6 +157,31 @@ USER_GROUP=$(id -gn "$CONSOLE_USER" 2>/dev/null || echo "staff")
 USERBLOCK
 }
 
+# credentials_block — user-attribution values, computed on the developer's
+# machine at install time (the label <console-user>@<machine> doesn't exist at
+# generation time). {{...}} tokens are substituted 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 embed the username in URL userinfo — percent-encode it.
+ENDOR_PYPI_URL="https://$(endor_urlenc_b64 "$ENDOR_ATTR_USER"):${ENDOR_API_SECRET}@{{FQDN_HOST}}/v1/namespaces/{{NAMESPACE}}/firewall/pypi/simple/"
+ENDOR_GO_PROXY_URL="https://$(endor_urlenc_b64 "$ENDOR_ATTR_USER"):${ENDOR_API_SECRET}@{{FQDN_HOST}}/v1/namespaces/{{NAMESPACE}}/firewall/go/,direct"
+
+export ENDOR_ATTR_LABEL ENDOR_ATTR_USER ENDOR_AUTH_B64 ENDOR_PYPI_URL ENDOR_GO_PROXY_URL
+
+echo "[endor] user attribution → ${ENDOR_ATTR_LABEL}"
+CREDBLOCK
+}
+
 # script_header <output> <description>
 script_header() {
   local output="$1"
@@ -192,6 +212,8 @@ build_script() {
 
   {
     script_header "$output" "$description"
+    credentials_block
+    echo ""
     emit_all_blocks
     echo "# ════════════════════════════════════════════════════════════════════════════"
     echo "# Env setup"
@@ -247,6 +269,8 @@ 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 +319,7 @@ 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 credentials_block in generate.sh (user-attribution values)"
 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..dee1980 100644
--- a/package-firewall/bash/lib/common.sh
+++ b/package-firewall/bash/lib/common.sh
@@ -24,6 +24,38 @@ 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
diff --git a/package-firewall/bash/templates/envsh.sh b/package-firewall/bash/templates/envsh.sh
index 361441c..55f46a1 100644
--- a/package-firewall/bash/templates/envsh.sh
+++ b/package-firewall/bash/templates/envsh.sh
@@ -1,17 +1,33 @@
 # 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. The attribution tokens
+# ({{ATTR_USER}}, {{NPM_AUTH_B64}}, {{PIP_INDEX_URL}}, {{GO_PROXY_URL}}) are
+# filled here at install time from the credentials block; a token filled by neither
+# generate.sh nor this step triggers a warning and a non-zero exit.
+#
+# pip / uv / go don't read env.sh — they can't expand ${VAR}; python.sh/go.sh
+# bake literal values 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}
+ENVSH_BLOCK=${ENVSH_BLOCK//'{{PIP_INDEX_URL}}'/$ENDOR_PYPI_URL}
+ENVSH_BLOCK=${ENVSH_BLOCK//'{{GO_PROXY_URL}}'/$ENDOR_GO_PROXY_URL}
+
+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..013b11d 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..9ae16fe 100644
--- a/package-firewall/bash/templates/js.sh
+++ b/package-firewall/bash/templates/js.sh
@@ -53,8 +53,13 @@ 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+).
+
+# The shared block says ${ENDOR_API_KEY_ID} (Windows-safe); swap to the
+# attributed user on bash. Remove once Windows gets attribution.
+YARNRC_BLOCK=${YARNRC_BLOCK//'${ENDOR_API_KEY_ID}'/'${ENDOR_ATTR_USER}'}
+
 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..c5769be 100644
--- a/package-firewall/bash/templates/maven.sh
+++ b/package-firewall/bash/templates/maven.sh
@@ -6,12 +6,16 @@
 
 # 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 ────────────────────────────────────────────────────────"
 
+# The shared block says ${env.ENDOR_API_KEY_ID} (Windows-safe); swap to the
+# attributed user on bash. Remove once Windows gets attribution.
+MAVEN_BLOCK=${MAVEN_BLOCK//'${env.ENDOR_API_KEY_ID}'/'${env.ENDOR_ATTR_USER}'}
+
 MAVEN_SETTINGS="$USER_HOME/.m2/settings.xml"
 
 # warn if the admin already defines a mirror/server outside an Endor block --
@@ -30,5 +34,5 @@ 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..aecfef2 100644
--- a/package-firewall/bash/templates/python.sh
+++ b/package-firewall/bash/templates/python.sh
@@ -10,15 +10,22 @@
 # 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/uv index-urls carry the attributed username, so their {{...}} tokens are
+# filled here at install time (from the credentials block).
+#
 # pip section uses [endor-firewall] named section — avoids clobbering admin's [global].
 
 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).
diff --git a/package-firewall/shared/blocks/envsh.txt b/package-firewall/shared/blocks/envsh.txt
index ff16ed0..707c1ee 100644
--- a/package-firewall/shared/blocks/envsh.txt
+++ b/package-firewall/shared/blocks/envsh.txt
@@ -1,9 +1,10 @@
 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}}"