diff --git a/hindsight-docs/docs-integrations/claude-code.md b/hindsight-docs/docs-integrations/claude-code.md
index 491e76a267..cb607f6ea3 100644
--- a/hindsight-docs/docs-integrations/claude-code.md
+++ b/hindsight-docs/docs-integrations/claude-code.md
@@ -204,7 +204,7 @@ Auto-retain runs after Claude responds. It extracts the conversation transcript
 | `retainOverlapTurns` | — | `2` | When chunked retention fires, this many extra turns from the previous chunk are included for continuity. Total window size = `retainEveryNTurns + retainOverlapTurns`. |
 | `retainRoles` | — | `["user", "assistant"]` | Which message roles to include in the retained transcript. |
 | `retainToolCalls` | — | `true` | Whether to include tool calls (function invocations and results) in the retained transcript. Captures structured actions like file reads, searches, and code edits. |
-| `retainTags` | — | `["{session_id}"]` | Tags attached to the retained document. Supports `{session_id}` placeholder which is replaced with the current session ID at runtime. |
+| `retainTags` | `HINDSIGHT_RETAIN_TAGS` | `["{session_id}"]` | Tags attached to the retained document. The env var accepts JSON or a comma-separated list. Supports `{session_id}` placeholder which is replaced with the current session ID at runtime. |
 | `retainMetadata` | — | `{}` | Arbitrary key-value metadata attached to the retained document. |
 | `retainContext` | — | `"claude-code"` | A label attached to retained memories identifying their source. Useful when multiple integrations write to the same bank. |
 
diff --git a/hindsight-integrations/claude-code/README.md b/hindsight-integrations/claude-code/README.md
index 50c67a892b..a2520963ba 100644
--- a/hindsight-integrations/claude-code/README.md
+++ b/hindsight-integrations/claude-code/README.md
@@ -248,7 +248,7 @@ Auto-retain runs after Claude responds. It extracts the conversation transcript
 | `retainOverlapTurns` | — | `2` | When chunked retention fires, this many extra turns from the previous chunk are included for continuity. Total window size = `retainEveryNTurns + retainOverlapTurns`. |
 | `retainRoles` | — | `["user", "assistant"]` | Which message roles to include in the retained transcript. |
 | `retainToolCalls` | — | `true` | Whether to include tool calls (function invocations and results) in the retained transcript. Captures structured actions like file reads, searches, and code edits. |
-| `retainTags` | — | `["{session_id}"]` | Tags attached to the retained document. Supports template placeholders: `{session_id}`, `{bank_id}`, `{timestamp}`, and `{user_id}` (resolved from `HINDSIGHT_USER_ID` env var; empty string if unset). Tags whose resolved form ends in an empty namespace part (e.g. `"user:"` when `HINDSIGHT_USER_ID` is unset) are dropped from the outgoing request. See [Template variables](#template-variables-for-retaintags-and-retainmetadata) below. |
+| `retainTags` | `HINDSIGHT_RETAIN_TAGS` | `["{session_id}"]` | Tags attached to the retained document. The env var accepts JSON or a comma-separated list. Supports template placeholders: `{session_id}`, `{bank_id}`, `{timestamp}`, and `{user_id}` (resolved from `HINDSIGHT_USER_ID` env var; empty string if unset). Tags whose resolved form ends in an empty namespace part (e.g. `"user:"` when `HINDSIGHT_USER_ID` is unset) are dropped from the outgoing request. See [Template variables](#template-variables-for-retaintags-and-retainmetadata) below. |
 | `retainMetadata` | — | `{}` | Arbitrary key-value metadata attached to the retained document. Same template placeholders as `retainTags`. |
 | `retainContext` | — | `"claude-code"` | A label attached to retained memories identifying their source. Useful when multiple integrations write to the same bank. |
 
diff --git a/hindsight-integrations/claude-code/scripts/lib/config.py b/hindsight-integrations/claude-code/scripts/lib/config.py
index 10ad13b245..f974149995 100644
--- a/hindsight-integrations/claude-code/scripts/lib/config.py
+++ b/hindsight-integrations/claude-code/scripts/lib/config.py
@@ -82,6 +82,7 @@
     "HINDSIGHT_RECALL_TAGS_MATCH": ("recallTagsMatch", str),
     "HINDSIGHT_RECALL_TAG_GROUPS": ("recallTagGroups", dict),
     "HINDSIGHT_RECALL_ADDITIONAL_BANK_FILTERS": ("recallAdditionalBankFilters", dict),
+    "HINDSIGHT_RETAIN_TAGS": ("retainTags", list),
     "HINDSIGHT_API_PORT": ("apiPort", int),
     "HINDSIGHT_DAEMON_IDLE_TIMEOUT": ("daemonIdleTimeout", int),
     "HINDSIGHT_REQUEST_TIMEOUT_SECONDS": ("requestTimeoutSeconds", int),
diff --git a/hindsight-integrations/claude-code/tests/test_config.py b/hindsight-integrations/claude-code/tests/test_config.py
index 5cb259a53c..1fc794b8c7 100644
--- a/hindsight-integrations/claude-code/tests/test_config.py
+++ b/hindsight-integrations/claude-code/tests/test_config.py
@@ -87,6 +87,12 @@ def test_recall_tags_env_override_accepts_comma_list(self, tmp_path, monkeypatch
         cfg = load_config()
         assert cfg["recallTags"] == ["memory_type:rule", "tech_stack:supabase"]
 
+    def test_retain_tags_env_override_accepts_comma_list(self, tmp_path, monkeypatch):
+        monkeypatch.setenv("CLAUDE_PLUGIN_ROOT", str(tmp_path))
+        monkeypatch.setenv("HINDSIGHT_RETAIN_TAGS", "project:payments, source:claude-code")
+        cfg = load_config()
+        assert cfg["retainTags"] == ["project:payments", "source:claude-code"]
+
     def test_recall_tag_groups_env_override_accepts_json(self, tmp_path, monkeypatch):
         monkeypatch.setenv("CLAUDE_PLUGIN_ROOT", str(tmp_path))
         monkeypatch.setenv(
diff --git a/skills/hindsight-docs/references/sdks/integrations/claude-code.md b/skills/hindsight-docs/references/sdks/integrations/claude-code.md
index 2e2bccf617..434e4b4ce8 100644
--- a/skills/hindsight-docs/references/sdks/integrations/claude-code.md
+++ b/skills/hindsight-docs/references/sdks/integrations/claude-code.md
@@ -198,7 +198,7 @@ Auto-retain runs after Claude responds. It extracts the conversation transcript
 | `retainOverlapTurns` | — | `2` | When chunked retention fires, this many extra turns from the previous chunk are included for continuity. Total window size = `retainEveryNTurns + retainOverlapTurns`. |
 | `retainRoles` | — | `["user", "assistant"]` | Which message roles to include in the retained transcript. |
 | `retainToolCalls` | — | `true` | Whether to include tool calls (function invocations and results) in the retained transcript. Captures structured actions like file reads, searches, and code edits. |
-| `retainTags` | — | `["{session_id}"]` | Tags attached to the retained document. Supports `{session_id}` placeholder which is replaced with the current session ID at runtime. |
+| `retainTags` | `HINDSIGHT_RETAIN_TAGS` | `["{session_id}"]` | Tags attached to the retained document. The env var accepts JSON or a comma-separated list. Supports `{session_id}` placeholder which is replaced with the current session ID at runtime. |
 | `retainMetadata` | — | `{}` | Arbitrary key-value metadata attached to the retained document. |
 | `retainContext` | — | `"claude-code"` | A label attached to retained memories identifying their source. Useful when multiple integrations write to the same bank. |