diff --git a/.agents/skills/gstack-benchmark/SKILL.md b/.agents/skills/gstack-benchmark/SKILL.md
index 4557cfda..aa8551a4 100644
--- a/.agents/skills/gstack-benchmark/SKILL.md
+++ b/.agents/skills/gstack-benchmark/SKILL.md
@@ -290,7 +290,7 @@ When the user types `/benchmark`, run this skill.
 ### Phase 1: Setup
 
 ```bash
-eval $(~/.codex/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
+source <(~/.codex/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
 mkdir -p .gstack/benchmark-reports
 mkdir -p .gstack/benchmark-reports/baselines
 ```
diff --git a/.agents/skills/gstack-canary/SKILL.md b/.agents/skills/gstack-canary/SKILL.md
index 416f8e5d..f1bb4ee5 100644
--- a/.agents/skills/gstack-canary/SKILL.md
+++ b/.agents/skills/gstack-canary/SKILL.md
@@ -308,7 +308,7 @@ When the user types `/canary`, run this skill.
 ### Phase 1: Setup
 
 ```bash
-eval $(~/.codex/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
+source <(~/.codex/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
 mkdir -p .gstack/canary-reports
 mkdir -p .gstack/canary-reports/baselines
 mkdir -p .gstack/canary-reports/screenshots
@@ -458,7 +458,7 @@ Save report to `.gstack/canary-reports/{date}-canary.md` and `.gstack/canary-rep
 Log the result for the review dashboard:
 
 ```bash
-eval $(~/.codex/skills/gstack/bin/gstack-slug 2>/dev/null)
+source <(~/.codex/skills/gstack/bin/gstack-slug 2>/dev/null)
 mkdir -p ~/.gstack/projects/$SLUG
 ```
 
diff --git a/.agents/skills/gstack-land-and-deploy/SKILL.md b/.agents/skills/gstack-land-and-deploy/SKILL.md
index d24d1191..e3106973 100644
--- a/.agents/skills/gstack-land-and-deploy/SKILL.md
+++ b/.agents/skills/gstack-land-and-deploy/SKILL.md
@@ -840,7 +840,7 @@ Save report to `.gstack/deploy-reports/{date}-pr{number}-deploy.md`.
 Log to the review dashboard:
 
 ```bash
-eval $(~/.codex/skills/gstack/bin/gstack-slug 2>/dev/null)
+source <(~/.codex/skills/gstack/bin/gstack-slug 2>/dev/null)
 mkdir -p ~/.gstack/projects/$SLUG
 ```
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 95f8e422..bfd59433 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -217,7 +217,7 @@
 - **Browse no longer navigates to dangerous URLs.** `goto`, `diff`, and `newtab` now block `file://`, `javascript:`, `data:` schemes and cloud metadata endpoints (`169.254.169.254`, `metadata.google.internal`). Localhost and private IPs are still allowed for local QA testing. (Closes #17)
 - **Setup script tells you what's missing.** Running `./setup` without `bun` installed now shows a clear error with install instructions instead of a cryptic "command not found." (Closes #147)
 - **`/debug` renamed to `/investigate`.** Claude Code has a built-in `/debug` command that shadowed the gstack skill. The systematic root-cause debugging workflow now lives at `/investigate`. (Closes #190)
-- **Shell injection surface removed.** All skill templates now use `source <(gstack-slug)` instead of `eval $(gstack-slug)`. Same behavior, no `eval`. (Closes #133)
+- **Shell injection surface reduced.** gstack-slug output is now sanitized to `[a-zA-Z0-9._-]` only, making both `eval` and `source` callers safe. (Closes #133)
 - **25 new security tests.** URL validation (16 tests) and path traversal validation (14 tests) now have dedicated unit test suites covering scheme blocking, metadata IP blocking, directory escapes, and prefix collision edge cases.
 
 ## [0.8.2] - 2026-03-19
diff --git a/benchmark/SKILL.md b/benchmark/SKILL.md
index c6845b2c..49e623f6 100644
--- a/benchmark/SKILL.md
+++ b/benchmark/SKILL.md
@@ -297,7 +297,7 @@ When the user types `/benchmark`, run this skill.
 ### Phase 1: Setup
 
 ```bash
-eval $(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
+source <(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
 mkdir -p .gstack/benchmark-reports
 mkdir -p .gstack/benchmark-reports/baselines
 ```
diff --git a/benchmark/SKILL.md.tmpl b/benchmark/SKILL.md.tmpl
index 3d4efac8..d0c0ecbc 100644
--- a/benchmark/SKILL.md.tmpl
+++ b/benchmark/SKILL.md.tmpl
@@ -41,7 +41,7 @@ When the user types `/benchmark`, run this skill.
 ### Phase 1: Setup
 
 ```bash
-eval $(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
+source <(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
 mkdir -p .gstack/benchmark-reports
 mkdir -p .gstack/benchmark-reports/baselines
 ```
diff --git a/bin/gstack-review-log b/bin/gstack-review-log
index ad29c172..816cfa46 100755
--- a/bin/gstack-review-log
+++ b/bin/gstack-review-log
@@ -3,7 +3,7 @@
 # Usage: gstack-review-log '{"skill":"...","timestamp":"...","status":"..."}'
 set -euo pipefail
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
-eval $("$SCRIPT_DIR/gstack-slug" 2>/dev/null)
+source <("$SCRIPT_DIR/gstack-slug" 2>/dev/null)
 GSTACK_HOME="${GSTACK_HOME:-$HOME/.gstack}"
 mkdir -p "$GSTACK_HOME/projects/$SLUG"
 echo "$1" >> "$GSTACK_HOME/projects/$SLUG/$BRANCH-reviews.jsonl"
diff --git a/bin/gstack-review-read b/bin/gstack-review-read
index 247c022f..578d7480 100755
--- a/bin/gstack-review-read
+++ b/bin/gstack-review-read
@@ -3,7 +3,7 @@
 # Usage: gstack-review-read
 set -euo pipefail
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
-eval $("$SCRIPT_DIR/gstack-slug" 2>/dev/null)
+source <("$SCRIPT_DIR/gstack-slug" 2>/dev/null)
 GSTACK_HOME="${GSTACK_HOME:-$HOME/.gstack}"
 cat "$GSTACK_HOME/projects/$SLUG/$BRANCH-reviews.jsonl" 2>/dev/null || echo "NO_REVIEWS"
 echo "---CONFIG---"
diff --git a/bin/gstack-slug b/bin/gstack-slug
index 77824726..3ad30381 100755
--- a/bin/gstack-slug
+++ b/bin/gstack-slug
@@ -1,10 +1,10 @@
 #!/usr/bin/env bash
 # gstack-slug — output project slug and sanitized branch name
-# Usage: eval $(gstack-slug)  → sets SLUG and BRANCH variables
-# Or:    gstack-slug          → prints SLUG=... and BRANCH=... lines
+# Usage: source <(gstack-slug)  → sets SLUG and BRANCH variables
+# Or:    gstack-slug            → prints SLUG=... and BRANCH=... lines
 #
 # Security: output is sanitized to [a-zA-Z0-9._-] only, preventing
-# shell injection when consumed via eval $(gstack-slug).
+# shell injection when consumed via source or eval.
 set -euo pipefail
 RAW_SLUG=$(git remote get-url origin 2>/dev/null | sed 's|.*[:/]\([^/]*/[^/]*\)\.git$|\1|;s|.*[:/]\([^/]*/[^/]*\)$|\1|' | tr '/' '-')
 RAW_BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null | tr '/' '-')
diff --git a/canary/SKILL.md b/canary/SKILL.md
index f3f1c1ae..304c1427 100644
--- a/canary/SKILL.md
+++ b/canary/SKILL.md
@@ -315,7 +315,7 @@ When the user types `/canary`, run this skill.
 ### Phase 1: Setup
 
 ```bash
-eval $(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
+source <(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
 mkdir -p .gstack/canary-reports
 mkdir -p .gstack/canary-reports/baselines
 mkdir -p .gstack/canary-reports/screenshots
@@ -465,7 +465,7 @@ Save report to `.gstack/canary-reports/{date}-canary.md` and `.gstack/canary-rep
 Log the result for the review dashboard:
 
 ```bash
-eval $(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)
+source <(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)
 mkdir -p ~/.gstack/projects/$SLUG
 ```
 
diff --git a/canary/SKILL.md.tmpl b/canary/SKILL.md.tmpl
index 8c9089be..d0ddadfe 100644
--- a/canary/SKILL.md.tmpl
+++ b/canary/SKILL.md.tmpl
@@ -42,7 +42,7 @@ When the user types `/canary`, run this skill.
 ### Phase 1: Setup
 
 ```bash
-eval $(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
+source <(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
 mkdir -p .gstack/canary-reports
 mkdir -p .gstack/canary-reports/baselines
 mkdir -p .gstack/canary-reports/screenshots
@@ -192,7 +192,7 @@ Save report to `.gstack/canary-reports/{date}-canary.md` and `.gstack/canary-rep
 Log the result for the review dashboard:
 
 ```bash
-eval $(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)
+source <(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)
 mkdir -p ~/.gstack/projects/$SLUG
 ```
 
diff --git a/land-and-deploy/SKILL.md b/land-and-deploy/SKILL.md
index 497fbc98..4a6369b6 100644
--- a/land-and-deploy/SKILL.md
+++ b/land-and-deploy/SKILL.md
@@ -847,7 +847,7 @@ Save report to `.gstack/deploy-reports/{date}-pr{number}-deploy.md`.
 Log to the review dashboard:
 
 ```bash
-eval $(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)
+source <(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)
 mkdir -p ~/.gstack/projects/$SLUG
 ```
 
diff --git a/land-and-deploy/SKILL.md.tmpl b/land-and-deploy/SKILL.md.tmpl
index d1ddd7b7..0e84d859 100644
--- a/land-and-deploy/SKILL.md.tmpl
+++ b/land-and-deploy/SKILL.md.tmpl
@@ -542,7 +542,7 @@ Save report to `.gstack/deploy-reports/{date}-pr{number}-deploy.md`.
 Log to the review dashboard:
 
 ```bash
-eval $(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)
+source <(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)
 mkdir -p ~/.gstack/projects/$SLUG
 ```