diff --git a/docs/scratchpads/536-wrapper-login-pin.md b/docs/scratchpads/536-wrapper-login-pin.md
new file mode 100644
index 0000000..f260b2b
--- /dev/null
+++ b/docs/scratchpads/536-wrapper-login-pin.md
@@ -0,0 +1,45 @@
+# Issue 536 Wrapper Login Pin Scratchpad
+
+## Metadata
+
+- Date: 2026-06-12
+- Worktree: `/home/hermes/agent-work/536-wrapper-audit`
+- Branch: `fix/536-wrapper-login-pin`
+- Coordinator: `mos-claude`
+- Issue: `mosaicstack/stack#536`
+- Scope: Audit and fix Gitea git wrappers that hardcode or incorrectly inherit tea login/instance selection.
+
+## Objective
+
+Fix the framework git wrappers so Gitea issue/PR operations resolve the tea login from the target repository host instead of pinning `mosaicstack`. The fix must cover the class of bug across `packages/mosaic/framework/tools/git/`, not only `issue-close.sh`.
+
+## Acceptance Criteria
+
+1. `issue-close.sh` no longer uses `--login mosaicstack` for non-mosaic hosts.
+2. All wrappers in `packages/mosaic/framework/tools/git/` avoid hardcoded Gitea login fallback where host-specific resolution is available.
+3. Host-specific resolution works for `git.mosaicstack.dev` and `git.uscllc.com` using configured credentials / tea login data.
+4. Read-only verification runs against both Gitea instances where possible.
+5. Queue guard passes before push, PR is opened referencing #536, and merge is left to the coordinator.
+
+## Progress Log
+
+- Read required Mosaic hard-gate docs and coordinator briefing.
+- Read issue #536 via Gitea API with mosaicstack credentials.
+- Initial audit found hardcoded `${GITEA_LOGIN:-mosaicstack}` in issue and PR wrappers, plus shared `get_gitea_repo_args`.
+- Added host-aware Gitea login resolution in `detect-platform.sh`, including exact host matching for `tea login list` entries and HTTPS remotes with embedded credentials.
+- Updated Gitea issue, PR, milestone, and CI wrappers to use resolved host-specific tea login arguments instead of defaulting to `mosaicstack`.
+- Added authenticated API fallbacks for close/reopen paths so wrappers can still operate when a matching `tea` login is absent but token credentials are available.
+- Added regression coverage for stale `GITEA_LOGIN`, exact host matching, `--repo` override flows, USC issue close routing, mosaicstack API fallback, and PR metadata/merge fallbacks.
+
+## Verification
+
+- `bash -n packages/mosaic/framework/tools/git/*.sh`
+- `packages/mosaic/framework/tools/git/test-gitea-login-resolution.sh`
+- `packages/mosaic/framework/tools/git/test-pr-metadata-gitea.sh`
+- `packages/mosaic/framework/tools/git/test-pr-merge-gitea-empty-uid.sh`
+- `pnpm typecheck`
+- `pnpm lint`
+- `pnpm format:check`
+- Live read-only: direct Gitea API read of `mosaicstack/stack#536` with `User-Agent: curl/8`.
+- Live read-only: USC temporary repo remote to `https://git.uscllc.com/USC/uconnect.git`; `issue-list.sh -n 1` resolved the USC login and returned USC issues.
+- Independent Codex review final verdict: approve, no findings.
diff --git a/packages/mosaic/framework/tools/git/ci-queue-wait.sh b/packages/mosaic/framework/tools/git/ci-queue-wait.sh
index 266577b..7fb42d3 100755
--- a/packages/mosaic/framework/tools/git/ci-queue-wait.sh
+++ b/packages/mosaic/framework/tools/git/ci-queue-wait.sh
@@ -137,7 +137,7 @@ gitea_get_branch_head_sha() {
     local branch="$3"
     local token="$4"
     local url="https://${host}/api/v1/repos/${repo}/branches/${branch}"
-    curl -fsSL -H "Authorization: token ${token}" "$url" | python3 -c '
+    curl -fsSL -H "User-Agent: curl/8" -H "Authorization: token ${token}" "$url" | python3 -c '
 import json, sys
 data = json.load(sys.stdin)
 commit = data.get("commit") or {}
@@ -151,7 +151,7 @@ gitea_get_commit_status_json() {
     local sha="$3"
     local token="$4"
     local url="https://${host}/api/v1/repos/${repo}/commits/${sha}/status"
-    curl -fsSL -H "Authorization: token ${token}" "$url"
+    curl -fsSL -H "User-Agent: curl/8" -H "Authorization: token ${token}" "$url"
 }
 
 while [[ $# -gt 0 ]]; do
diff --git a/packages/mosaic/framework/tools/git/detect-platform.sh b/packages/mosaic/framework/tools/git/detect-platform.sh
index df3dff5..6835d56 100755
--- a/packages/mosaic/framework/tools/git/detect-platform.sh
+++ b/packages/mosaic/framework/tools/git/detect-platform.sh
@@ -78,10 +78,186 @@ get_repo_slug() {
     get_repo_info
 }
 
+gitea_url_matches_host() {
+    local url="${1:-}" host="${2:-}"
+    [[ -n "$url" && -n "$host" ]] || return 1
+    [[ "${url%/}" == "https://$host" || "${url%/}" == "http://$host" || "${url%/}" == *"//$host" ]]
+}
+
+get_gitea_service_for_host() {
+    local host="$1"
+    local cred_file="${MOSAIC_CREDENTIALS_FILE:-$HOME/src/jarvis-brain/credentials.json}"
+
+    case "$host" in
+        git.mosaicstack.dev)
+            echo "mosaicstack"
+            return 0
+            ;;
+        git.uscllc.com)
+            echo "usc"
+            return 0
+            ;;
+    esac
+
+    [[ -f "$cred_file" ]] || return 1
+    command -v jq >/dev/null 2>&1 || return 1
+
+    jq -r --arg host "$host" '
+        .gitea // {}
+        | to_entries[]
+        | select((.value.url // "" | sub("/+$"; "")) | test("https?://" + $host + "$"))
+        | .key
+    ' "$cred_file" | head -n 1
+}
+
+find_tea_login_for_host() {
+    local host="$1"
+    local logins_json
+
+    command -v tea >/dev/null 2>&1 || return 1
+    logins_json=$(tea login list --output json 2>/dev/null) || return 1
+    TEA_LOGINS_JSON="$logins_json" python3 - "$host" <<'PY'
+import json
+import os
+import sys
+from urllib.parse import urlparse
+
+host = sys.argv[1]
+try:
+    logins = json.loads(os.environ.get("TEA_LOGINS_JSON", "[]"))
+except Exception:
+    raise SystemExit(1)
+
+for login in logins if isinstance(logins, list) else []:
+    url = str(login.get("url") or login.get("URL") or "")
+    name = str(login.get("name") or login.get("Name") or "")
+    parsed = urlparse(url)
+    if parsed.hostname == host and name:
+        print(name)
+        raise SystemExit(0)
+
+raise SystemExit(1)
+PY
+}
+
+tea_login_matches_host() {
+    local login_name="$1" host="$2"
+    local logins_json
+
+    command -v tea >/dev/null 2>&1 || return 1
+    logins_json=$(tea login list --output json 2>/dev/null) || return 1
+    TEA_LOGINS_JSON="$logins_json" python3 - "$login_name" "$host" <<'PY'
+import json
+import os
+import sys
+from urllib.parse import urlparse
+
+login_name, host = sys.argv[1], sys.argv[2]
+try:
+    logins = json.loads(os.environ.get("TEA_LOGINS_JSON", "[]"))
+except Exception:
+    raise SystemExit(1)
+
+for login in logins if isinstance(logins, list) else []:
+    url = str(login.get("url") or login.get("URL") or "")
+    name = str(login.get("name") or login.get("Name") or "")
+    parsed = urlparse(url)
+    if name == login_name and parsed.hostname == host:
+        raise SystemExit(0)
+
+raise SystemExit(1)
+PY
+}
+
+get_gitea_login_for_host() {
+    local host="${1:-}"
+    local login
+
+    if [[ -z "$host" ]]; then
+        host=$(get_remote_host) || return 1
+    fi
+
+    if [[ -n "${GITEA_LOGIN:-}" ]]; then
+        if gitea_url_matches_host "${GITEA_URL:-}" "$host" || tea_login_matches_host "$GITEA_LOGIN" "$host"; then
+            echo "$GITEA_LOGIN"
+            return 0
+        fi
+    fi
+
+    login=$(find_tea_login_for_host "$host" || true)
+    if [[ -n "$login" ]]; then
+        echo "$login"
+        return 0
+    fi
+
+    return 1
+}
+
+get_default_tea_login() {
+    local logins_json
+
+    command -v tea >/dev/null 2>&1 || return 1
+    logins_json=$(tea login list --output json 2>/dev/null) || return 1
+    TEA_LOGINS_JSON="$logins_json" python3 - <<'PY'
+import json
+import os
+
+try:
+    logins = json.loads(os.environ.get("TEA_LOGINS_JSON", "[]"))
+except Exception:
+    raise SystemExit(1)
+
+if not isinstance(logins, list) or not logins:
+    raise SystemExit(1)
+
+for login in logins:
+    if not isinstance(login, dict):
+        continue
+    is_default = str(login.get("default") or login.get("Default") or "").lower()
+    name = str(login.get("name") or login.get("Name") or "")
+    if name and is_default == "true":
+        print(name)
+        raise SystemExit(0)
+
+for login in logins:
+    if not isinstance(login, dict):
+        continue
+    name = str(login.get("name") or login.get("Name") or "")
+    if name:
+        print(name)
+        raise SystemExit(0)
+
+raise SystemExit(1)
+PY
+}
+
+get_gitea_login_for_repo_override() {
+    local login
+
+    if [[ -n "${GITEA_LOGIN:-}" ]]; then
+        echo "$GITEA_LOGIN"
+        return 0
+    fi
+
+    login=$(get_default_tea_login || true)
+    if [[ -n "$login" ]]; then
+        echo "$login"
+        return 0
+    fi
+
+    return 1
+}
+
 get_gitea_repo_args() {
-    local repo
+    local repo host login
     repo=$(get_repo_slug) || return 1
-    printf -- '--repo %q --login %q' "$repo" "${GITEA_LOGIN:-mosaicstack}"
+    host=$(get_remote_host) || return 1
+    login=$(get_gitea_login_for_host "$host") || return 1
+    printf -- '--repo %q --login %q' "$repo" "$login"
+}
+
+get_gitea_login() {
+    get_gitea_login_for_host "$(get_remote_host)"
 }
 
 get_remote_host() {
@@ -91,7 +267,8 @@ get_remote_host() {
         return 1
     fi
     if [[ "$remote_url" =~ ^https?://([^/]+)/ ]]; then
-        echo "${BASH_REMATCH[1]}"
+        local host="${BASH_REMATCH[1]}"
+        echo "${host##*@}"
         return 0
     fi
     if [[ "$remote_url" =~ ^git@([^:]+): ]]; then
diff --git a/packages/mosaic/framework/tools/git/issue-assign.sh b/packages/mosaic/framework/tools/git/issue-assign.sh
index 941f22a..f3a15cb 100755
--- a/packages/mosaic/framework/tools/git/issue-assign.sh
+++ b/packages/mosaic/framework/tools/git/issue-assign.sh
@@ -98,7 +98,11 @@ case "$PLATFORM" in
         ;;
     gitea)
         # tea issue edit syntax
-        CMD="tea issue edit $ISSUE"
+        REPO_ARGS=$(get_gitea_repo_args) || {
+            echo "Error: Could not resolve Gitea repo/login args for remote host" >&2
+            exit 1
+        }
+        CMD="tea issue edit $ISSUE $REPO_ARGS"
         NEEDS_EDIT=false
 
         if [[ -n "$ASSIGNEE" ]]; then
@@ -112,7 +116,7 @@ case "$PLATFORM" in
             NEEDS_EDIT=true
         fi
         if [[ -n "$MILESTONE" ]]; then
-            MILESTONE_ID=$(tea milestones list 2>/dev/null | grep -E "^\s*[0-9]+" | grep "$MILESTONE" | awk '{print $1}' | head -1)
+            MILESTONE_ID=$(tea milestones list $REPO_ARGS 2>/dev/null | grep -E "^\s*[0-9]+" | grep "$MILESTONE" | awk '{print $1}' | head -1)
             if [[ -n "$MILESTONE_ID" ]]; then
                 CMD="$CMD --milestone $MILESTONE_ID"
                 NEEDS_EDIT=true
diff --git a/packages/mosaic/framework/tools/git/issue-close.sh b/packages/mosaic/framework/tools/git/issue-close.sh
index b773357..646c8b0 100755
--- a/packages/mosaic/framework/tools/git/issue-close.sh
+++ b/packages/mosaic/framework/tools/git/issue-close.sh
@@ -44,10 +44,43 @@ if [[ -z "$ISSUE_NUMBER" ]]; then
 fi
 
 # Detect platform and close issue
-detect_platform
+detect_platform >/dev/null
 OWNER=$(get_repo_owner)
 REPO=$(get_repo_name)
 
+gitea_issue_comment_api() {
+    local host token url payload
+    host=$(get_remote_host) || return 1
+    token=$(get_gitea_token "$host") || return 1
+    url="https://${host}/api/v1/repos/${OWNER}/${REPO}/issues/${ISSUE_NUMBER}/comments"
+    payload=$(COMMENT="$COMMENT" python3 - <<'PY'
+import json
+import os
+
+print(json.dumps({"body": os.environ["COMMENT"]}))
+PY
+)
+    curl -fsS -X POST \
+        -H "User-Agent: curl/8" \
+        -H "Authorization: token ${token}" \
+        -H "Content-Type: application/json" \
+        -d "$payload" \
+        "$url" >/dev/null
+}
+
+gitea_issue_close_api() {
+    local host token url
+    host=$(get_remote_host) || return 1
+    token=$(get_gitea_token "$host") || return 1
+    url="https://${host}/api/v1/repos/${OWNER}/${REPO}/issues/${ISSUE_NUMBER}"
+    curl -fsS -X PATCH \
+        -H "User-Agent: curl/8" \
+        -H "Authorization: token ${token}" \
+        -H "Content-Type: application/json" \
+        -d '{"state":"closed"}' \
+        "$url" >/dev/null
+}
+
 if [[ "$PLATFORM" == "github" ]]; then
     if [[ -n "$COMMENT" ]]; then
         gh issue comment "$ISSUE_NUMBER" --body "$COMMENT"
@@ -55,10 +88,19 @@ if [[ "$PLATFORM" == "github" ]]; then
     gh issue close "$ISSUE_NUMBER"
     echo "Closed GitHub issue #$ISSUE_NUMBER"
 elif [[ "$PLATFORM" == "gitea" ]]; then
-    if [[ -n "$COMMENT" ]]; then
-        tea issue comment "$ISSUE_NUMBER" "$COMMENT" --repo "$OWNER/$REPO" --login "${GITEA_LOGIN:-mosaicstack}"
+    GITEA_LOGIN_NAME=$(get_gitea_login || true)
+    if [[ -n "$GITEA_LOGIN_NAME" ]]; then
+        if [[ -n "$COMMENT" ]]; then
+            tea issue comment "$ISSUE_NUMBER" "$COMMENT" --repo "$OWNER/$REPO" --login "$GITEA_LOGIN_NAME"
+        fi
+        tea issue close "$ISSUE_NUMBER" --repo "$OWNER/$REPO" --login "$GITEA_LOGIN_NAME"
+    else
+        echo "No tea login configured for $(get_remote_host); using authenticated Gitea API fallback." >&2
+        if [[ -n "$COMMENT" ]]; then
+            gitea_issue_comment_api
+        fi
+        gitea_issue_close_api
     fi
-    tea issue close "$ISSUE_NUMBER" --repo "$OWNER/$REPO" --login "${GITEA_LOGIN:-mosaicstack}"
     echo "Closed Gitea issue #$ISSUE_NUMBER"
 else
     echo "Error: Unknown platform"
diff --git a/packages/mosaic/framework/tools/git/issue-comment.sh b/packages/mosaic/framework/tools/git/issue-comment.sh
index b1cc4ad..70f4a42 100755
--- a/packages/mosaic/framework/tools/git/issue-comment.sh
+++ b/packages/mosaic/framework/tools/git/issue-comment.sh
@@ -47,7 +47,7 @@ if [[ -z "$COMMENT" ]]; then
     exit 1
 fi
 
-detect_platform
+detect_platform >/dev/null
 
 if [[ "$PLATFORM" == "github" ]]; then
     gh issue comment "$ISSUE_NUMBER" --body "$COMMENT"
diff --git a/packages/mosaic/framework/tools/git/issue-create.sh b/packages/mosaic/framework/tools/git/issue-create.sh
index 6fd1799..d516ed0 100755
--- a/packages/mosaic/framework/tools/git/issue-create.sh
+++ b/packages/mosaic/framework/tools/git/issue-create.sh
@@ -48,6 +48,7 @@ PY
 
     url="https://${host}/api/v1/repos/${repo}/issues"
     curl -fsS -X POST \
+      -H "User-Agent: curl/8" \
       -H "Authorization: token ${token}" \
       -H "Content-Type: application/json" \
       -d "$payload" \
@@ -121,7 +122,12 @@ case "$PLATFORM" in
     gitea)
         if command -v tea >/dev/null 2>&1; then
             REPO_SLUG=$(get_repo_slug)
-            REPO_ARGS=(--repo "$REPO_SLUG" --login "${GITEA_LOGIN:-mosaicstack}")
+            GITEA_LOGIN_NAME=$(get_gitea_login) || {
+                echo "Warning: could not resolve Gitea login for tea; trying Gitea API fallback..." >&2
+                gitea_issue_create_api
+                exit $?
+            }
+            REPO_ARGS=(--repo "$REPO_SLUG" --login "$GITEA_LOGIN_NAME")
             CMD=(tea issue create "${REPO_ARGS[@]}" --title "$TITLE")
             [[ -n "$BODY" ]] && CMD+=(--description "$BODY")
             [[ -n "$LABELS" ]] && CMD+=(--labels "$LABELS")
diff --git a/packages/mosaic/framework/tools/git/issue-edit.sh b/packages/mosaic/framework/tools/git/issue-edit.sh
index 70d57c9..0ffcc0b 100755
--- a/packages/mosaic/framework/tools/git/issue-edit.sh
+++ b/packages/mosaic/framework/tools/git/issue-edit.sh
@@ -60,7 +60,7 @@ if [[ -z "$ISSUE_NUMBER" ]]; then
     exit 1
 fi
 
-detect_platform
+detect_platform >/dev/null
 
 if [[ "$PLATFORM" == "github" ]]; then
     CMD="gh issue edit $ISSUE_NUMBER"
@@ -71,7 +71,11 @@ if [[ "$PLATFORM" == "github" ]]; then
     eval $CMD
     echo "Updated GitHub issue #$ISSUE_NUMBER"
 elif [[ "$PLATFORM" == "gitea" ]]; then
-    CMD="tea issue edit $ISSUE_NUMBER"
+    REPO_ARGS=$(get_gitea_repo_args) || {
+        echo "Error: Could not resolve Gitea repo/login args for remote host" >&2
+        exit 1
+    }
+    CMD="tea issue edit $ISSUE_NUMBER $REPO_ARGS"
     [[ -n "$TITLE" ]] && CMD="$CMD --title \"$TITLE\""
     [[ -n "$BODY" ]] && CMD="$CMD --description \"$BODY\""
     [[ -n "$LABELS" ]] && CMD="$CMD --add-labels \"$LABELS\""
diff --git a/packages/mosaic/framework/tools/git/issue-list.sh b/packages/mosaic/framework/tools/git/issue-list.sh
index b162592..dd7b73d 100755
--- a/packages/mosaic/framework/tools/git/issue-list.sh
+++ b/packages/mosaic/framework/tools/git/issue-list.sh
@@ -98,7 +98,18 @@ case "$PLATFORM" in
         "${CMD[@]}"
         ;;
     gitea)
-        CMD=(tea issues list --repo "$REPO_INFO" --login "${GITEA_LOGIN:-mosaicstack}" --state "$STATE" --limit "$LIMIT")
+        if [[ -n "$REPO_OVERRIDE" ]]; then
+            GITEA_LOGIN_NAME=$(get_gitea_login_for_repo_override) || {
+                echo "Error: Could not resolve Gitea login for --repo override. Set GITEA_LOGIN or configure a default tea login." >&2
+                exit 1
+            }
+        else
+            GITEA_LOGIN_NAME=$(get_gitea_login) || {
+                echo "Error: Could not resolve Gitea login for remote host" >&2
+                exit 1
+            }
+        fi
+        CMD=(tea issues list --repo "$REPO_INFO" --login "$GITEA_LOGIN_NAME" --state "$STATE" --limit "$LIMIT")
         [[ -n "$LABEL" ]] && CMD+=(--labels "$LABEL")
         [[ -n "$MILESTONE" ]] && CMD+=(--milestones "$MILESTONE")
         # Note: tea may not support assignee filter directly in all versions.
diff --git a/packages/mosaic/framework/tools/git/issue-reopen.sh b/packages/mosaic/framework/tools/git/issue-reopen.sh
index 734fe34..cb92acd 100755
--- a/packages/mosaic/framework/tools/git/issue-reopen.sh
+++ b/packages/mosaic/framework/tools/git/issue-reopen.sh
@@ -42,7 +42,42 @@ if [[ -z "$ISSUE_NUMBER" ]]; then
     exit 1
 fi
 
-detect_platform
+detect_platform >/dev/null
+OWNER=$(get_repo_owner)
+REPO=$(get_repo_name)
+
+gitea_issue_comment_api() {
+    local host token url payload
+    host=$(get_remote_host) || return 1
+    token=$(get_gitea_token "$host") || return 1
+    url="https://${host}/api/v1/repos/${OWNER}/${REPO}/issues/${ISSUE_NUMBER}/comments"
+    payload=$(COMMENT="$COMMENT" python3 - <<'PY'
+import json
+import os
+
+print(json.dumps({"body": os.environ["COMMENT"]}))
+PY
+)
+    curl -fsS -X POST \
+        -H "User-Agent: curl/8" \
+        -H "Authorization: token ${token}" \
+        -H "Content-Type: application/json" \
+        -d "$payload" \
+        "$url" >/dev/null
+}
+
+gitea_issue_reopen_api() {
+    local host token url
+    host=$(get_remote_host) || return 1
+    token=$(get_gitea_token "$host") || return 1
+    url="https://${host}/api/v1/repos/${OWNER}/${REPO}/issues/${ISSUE_NUMBER}"
+    curl -fsS -X PATCH \
+        -H "User-Agent: curl/8" \
+        -H "Authorization: token ${token}" \
+        -H "Content-Type: application/json" \
+        -d '{"state":"open"}' \
+        "$url" >/dev/null
+}
 
 if [[ "$PLATFORM" == "github" ]]; then
     if [[ -n "$COMMENT" ]]; then
@@ -51,10 +86,19 @@ if [[ "$PLATFORM" == "github" ]]; then
     gh issue reopen "$ISSUE_NUMBER"
     echo "Reopened GitHub issue #$ISSUE_NUMBER"
 elif [[ "$PLATFORM" == "gitea" ]]; then
-    if [[ -n "$COMMENT" ]]; then
-        tea issue comment "$ISSUE_NUMBER" "$COMMENT" $(get_gitea_repo_args)
+    REPO_ARGS=$(get_gitea_repo_args || true)
+    if [[ -n "$REPO_ARGS" ]]; then
+        if [[ -n "$COMMENT" ]]; then
+            tea issue comment "$ISSUE_NUMBER" "$COMMENT" $REPO_ARGS
+        fi
+        tea issue reopen "$ISSUE_NUMBER" $REPO_ARGS
+    else
+        echo "No tea login configured for $(get_remote_host); using authenticated Gitea API fallback." >&2
+        if [[ -n "$COMMENT" ]]; then
+            gitea_issue_comment_api
+        fi
+        gitea_issue_reopen_api
     fi
-    tea issue reopen "$ISSUE_NUMBER" $(get_gitea_repo_args)
     echo "Reopened Gitea issue #$ISSUE_NUMBER"
 else
     echo "Error: Unknown platform"
diff --git a/packages/mosaic/framework/tools/git/issue-view.sh b/packages/mosaic/framework/tools/git/issue-view.sh
index 18460e5..eccab98 100755
--- a/packages/mosaic/framework/tools/git/issue-view.sh
+++ b/packages/mosaic/framework/tools/git/issue-view.sh
@@ -29,9 +29,9 @@ gitea_issue_view_api() {
 
     url="https://${host}/api/v1/repos/${repo}/issues/${ISSUE_NUMBER}"
     if command -v python3 >/dev/null 2>&1; then
-        curl -fsS -H "Authorization: token ${token}" "$url" | python3 -m json.tool
+        curl -fsS -H "User-Agent: curl/8" -H "Authorization: token ${token}" "$url" | python3 -m json.tool
     else
-        curl -fsS -H "Authorization: token ${token}" "$url"
+        curl -fsS -H "User-Agent: curl/8" -H "Authorization: token ${token}" "$url"
     fi
 }
 
@@ -61,7 +61,7 @@ if [[ -z "$ISSUE_NUMBER" ]]; then
     exit 1
 fi
 
-detect_platform
+detect_platform >/dev/null
 
 if [[ "$PLATFORM" == "github" ]]; then
     gh issue view "$ISSUE_NUMBER"
diff --git a/packages/mosaic/framework/tools/git/milestone-close.sh b/packages/mosaic/framework/tools/git/milestone-close.sh
index ac7ad89..9d5a9f7 100755
--- a/packages/mosaic/framework/tools/git/milestone-close.sh
+++ b/packages/mosaic/framework/tools/git/milestone-close.sh
@@ -36,7 +36,7 @@ if [[ -z "$TITLE" ]]; then
     exit 1
 fi
 
-detect_platform
+detect_platform >/dev/null
 
 if [[ "$PLATFORM" == "github" ]]; then
     gh api -X PATCH "/repos/{owner}/{repo}/milestones/$(gh api "/repos/{owner}/{repo}/milestones" --jq ".[] | select(.title==\"$TITLE\") | .number")" -f state=closed
diff --git a/packages/mosaic/framework/tools/git/milestone-list.sh b/packages/mosaic/framework/tools/git/milestone-list.sh
index e9b8656..c28b0eb 100755
--- a/packages/mosaic/framework/tools/git/milestone-list.sh
+++ b/packages/mosaic/framework/tools/git/milestone-list.sh
@@ -31,7 +31,7 @@ while [[ $# -gt 0 ]]; do
     esac
 done
 
-detect_platform
+detect_platform >/dev/null
 
 if [[ "$PLATFORM" == "github" ]]; then
     gh api "/repos/{owner}/{repo}/milestones?state=$STATE" --jq '.[] | "\(.title) (\(.state)) - \(.open_issues) open, \(.closed_issues) closed"'
diff --git a/packages/mosaic/framework/tools/git/pr-ci-wait.sh b/packages/mosaic/framework/tools/git/pr-ci-wait.sh
index 50c8b21..d9f0a6c 100755
--- a/packages/mosaic/framework/tools/git/pr-ci-wait.sh
+++ b/packages/mosaic/framework/tools/git/pr-ci-wait.sh
@@ -124,7 +124,7 @@ gitea_get_pr_head_sha() {
     local repo="$2"
     local token="$3"
     local url="https://${host}/api/v1/repos/${repo}/pulls/${PR_NUMBER}"
-    curl -fsSL -H "Authorization: token ${token}" "$url" | python3 -c '
+    curl -fsSL -H "User-Agent: curl/8" -H "Authorization: token ${token}" "$url" | python3 -c '
 import json, sys
 data = json.load(sys.stdin)
 print((data.get("head") or {}).get("sha", ""))
@@ -137,7 +137,7 @@ gitea_get_commit_status_json() {
     local token="$3"
     local sha="$4"
     local url="https://${host}/api/v1/repos/${repo}/commits/${sha}/status"
-    curl -fsSL -H "Authorization: token ${token}" "$url"
+    curl -fsSL -H "User-Agent: curl/8" -H "Authorization: token ${token}" "$url"
 }
 
 while [[ $# -gt 0 ]]; do
diff --git a/packages/mosaic/framework/tools/git/pr-close.sh b/packages/mosaic/framework/tools/git/pr-close.sh
index afdfd3e..9fcb00f 100755
--- a/packages/mosaic/framework/tools/git/pr-close.sh
+++ b/packages/mosaic/framework/tools/git/pr-close.sh
@@ -42,7 +42,7 @@ if [[ -z "$PR_NUMBER" ]]; then
     exit 1
 fi
 
-detect_platform
+detect_platform >/dev/null
 
 if [[ "$PLATFORM" == "github" ]]; then
     if [[ -n "$COMMENT" ]]; then
diff --git a/packages/mosaic/framework/tools/git/pr-create.sh b/packages/mosaic/framework/tools/git/pr-create.sh
index 30747d8..60997e6 100755
--- a/packages/mosaic/framework/tools/git/pr-create.sh
+++ b/packages/mosaic/framework/tools/git/pr-create.sh
@@ -56,6 +56,7 @@ PY
 
     url="https://${host}/api/v1/repos/${repo}/pulls"
     curl -fsS -X POST \
+      -H "User-Agent: curl/8" \
       -H "Authorization: token ${token}" \
       -H "Content-Type: application/json" \
       -d "$payload" \
@@ -177,7 +178,12 @@ case "$PLATFORM" in
         # is unreliable in Mosaic worktrees/profile shells. Use arrays instead
         # of eval so markdown backticks/body content are not shell-executed.
         REPO_SLUG=$(get_repo_slug)
-        REPO_ARGS=(--repo "$REPO_SLUG" --login "${GITEA_LOGIN:-mosaicstack}")
+        GITEA_LOGIN_NAME=$(get_gitea_login) || {
+            echo "Warning: could not resolve Gitea login for tea; trying Gitea API fallback..." >&2
+            gitea_pr_create_api
+            exit $?
+        }
+        REPO_ARGS=(--repo "$REPO_SLUG" --login "$GITEA_LOGIN_NAME")
         CMD=(tea pr create "${REPO_ARGS[@]}" --title "$TITLE")
         [[ -n "$BODY" ]] && CMD+=(--description "$BODY")
         [[ -n "$BASE_BRANCH" ]] && CMD+=(--base "$BASE_BRANCH")
diff --git a/packages/mosaic/framework/tools/git/pr-diff.sh b/packages/mosaic/framework/tools/git/pr-diff.sh
index 2b2cfc7..34792d9 100755
--- a/packages/mosaic/framework/tools/git/pr-diff.sh
+++ b/packages/mosaic/framework/tools/git/pr-diff.sh
@@ -76,9 +76,9 @@ elif [[ "$PLATFORM" == "gitea" ]]; then
     GITEA_API_TOKEN=$(get_gitea_token "$HOST" || true)
 
     if [[ -n "$GITEA_API_TOKEN" ]]; then
-        DIFF_CONTENT=$(curl -sS -H "Authorization: token $GITEA_API_TOKEN" "$DIFF_URL")
+        DIFF_CONTENT=$(curl -sS -H "User-Agent: curl/8" -H "Authorization: token $GITEA_API_TOKEN" "$DIFF_URL")
     else
-        DIFF_CONTENT=$(curl -sS "$DIFF_URL")
+        DIFF_CONTENT=$(curl -sS -H "User-Agent: curl/8" "$DIFF_URL")
     fi
 
     if [[ -n "$OUTPUT_FILE" ]]; then
diff --git a/packages/mosaic/framework/tools/git/pr-list.sh b/packages/mosaic/framework/tools/git/pr-list.sh
index 7f0719b..0b923d2 100755
--- a/packages/mosaic/framework/tools/git/pr-list.sh
+++ b/packages/mosaic/framework/tools/git/pr-list.sh
@@ -93,7 +93,18 @@ case "$PLATFORM" in
         "${CMD[@]}"
         ;;
     gitea)
-        CMD=(tea pr list --repo "$REPO_INFO" --login "${GITEA_LOGIN:-mosaicstack}" --state "$STATE" --limit "$LIMIT")
+        if [[ -n "$REPO_OVERRIDE" ]]; then
+            GITEA_LOGIN_NAME=$(get_gitea_login_for_repo_override) || {
+                echo "Error: Could not resolve Gitea login for --repo override. Set GITEA_LOGIN or configure a default tea login." >&2
+                exit 1
+            }
+        else
+            GITEA_LOGIN_NAME=$(get_gitea_login) || {
+                echo "Error: Could not resolve Gitea login for remote host" >&2
+                exit 1
+            }
+        fi
+        CMD=(tea pr list --repo "$REPO_INFO" --login "$GITEA_LOGIN_NAME" --state "$STATE" --limit "$LIMIT")
 
         # tea filtering may be limited
         if [[ -n "$LABEL" ]]; then
diff --git a/packages/mosaic/framework/tools/git/pr-merge.sh b/packages/mosaic/framework/tools/git/pr-merge.sh
index 3c48b08..be658a8 100755
--- a/packages/mosaic/framework/tools/git/pr-merge.sh
+++ b/packages/mosaic/framework/tools/git/pr-merge.sh
@@ -106,34 +106,6 @@ PLATFORM=$(detect_platform)
 OWNER=$(get_repo_owner)
 REPO=$(get_repo_name)
 
-find_tea_login_for_host() {
-    local host="$1"
-    local logins_json
-
-    command -v tea >/dev/null 2>&1 || return 1
-    logins_json=$(tea login list --output json 2>/dev/null) || return 1
-    TEA_LOGINS_JSON="$logins_json" python3 - "$host" <<'PY'
-import json
-import os
-import sys
-
-host = sys.argv[1]
-try:
-    logins = json.loads(os.environ.get("TEA_LOGINS_JSON", "[]"))
-except Exception:
-    raise SystemExit(1)
-
-for login in logins if isinstance(logins, list) else []:
-    url = str(login.get("url") or login.get("URL") or "")
-    name = str(login.get("name") or login.get("Name") or "")
-    if url.rstrip("/").endswith(host) and name:
-        print(name)
-        raise SystemExit(0)
-
-raise SystemExit(1)
-PY
-}
-
 is_known_tea_empty_identity_failure() {
     local error_file="$1"
 
@@ -164,6 +136,7 @@ merge_gitea_with_api() {
     if [[ -n "$token" ]]; then
         raw_code=$(curl -sS -w '%{http_code}' -o "$body_file" \
             -X POST \
+            -H "User-Agent: curl/8" \
             -H "Authorization: token $token" \
             -H 'Content-Type: application/json' \
             -d "$payload" \
@@ -179,6 +152,7 @@ merge_gitea_with_api() {
         raw_code=$(curl -sS -w '%{http_code}' -o "$body_file" \
             -X POST \
             -u "$basic_auth" \
+            -H "User-Agent: curl/8" \
             -H 'Content-Type: application/json' \
             -d "$payload" \
             "$api_url" || true)
@@ -214,7 +188,7 @@ if [[ "$DRY_RUN" == true ]]; then
             echo "Error: Cannot determine host from origin remote URL" >&2
             exit 1
         }
-        TEA_LOGIN="${GITEA_LOGIN:-$(find_tea_login_for_host "$HOST" || true)}"
+        TEA_LOGIN="$(get_gitea_login_for_host "$HOST" || true)"
         if [[ -n "$TEA_LOGIN" ]]; then
             echo "Dry run: would merge PR #$PR_NUMBER on $HOST with tea login '$TEA_LOGIN' (base=$BASE_BRANCH, method=squash)."
         else
@@ -237,7 +211,7 @@ case "$PLATFORM" in
             echo "Error: Cannot determine host from origin remote URL" >&2
             exit 1
         }
-        TEA_LOGIN="${GITEA_LOGIN:-$(find_tea_login_for_host "$HOST" || true)}"
+        TEA_LOGIN="$(get_gitea_login_for_host "$HOST" || true)"
 
         if [[ -n "$TEA_LOGIN" ]]; then
             mkdir -p "${AGENT_WORK_ROOT:-/home/hermes/agent-work}"
diff --git a/packages/mosaic/framework/tools/git/pr-metadata.sh b/packages/mosaic/framework/tools/git/pr-metadata.sh
index 40fc0d2..b6373bf 100755
--- a/packages/mosaic/framework/tools/git/pr-metadata.sh
+++ b/packages/mosaic/framework/tools/git/pr-metadata.sh
@@ -59,7 +59,7 @@ curl_gitea_pull() {
 
     token=$(get_gitea_token "$HOST" || true)
     if [[ -n "$token" ]]; then
-        raw_code=$(curl -sS -w '%{http_code}' -o "$body_file" -H "Authorization: token $token" "$api_url" || true)
+        raw_code=$(curl -sS -w '%{http_code}' -o "$body_file" -H "User-Agent: curl/8" -H "Authorization: token $token" "$api_url" || true)
         if [[ "$raw_code" =~ ^2 ]]; then
             cat "$body_file"
             rm -f "$body_file"
@@ -70,7 +70,7 @@ curl_gitea_pull() {
 
     basic_auth=$(get_gitea_basic_auth "$HOST" || true)
     if [[ -n "$basic_auth" ]]; then
-        raw_code=$(curl -sS -w '%{http_code}' -o "$body_file" -u "$basic_auth" "$api_url" || true)
+        raw_code=$(curl -sS -w '%{http_code}' -o "$body_file" -u "$basic_auth" -H "User-Agent: curl/8" "$api_url" || true)
         if [[ "$raw_code" =~ ^2 ]]; then
             cat "$body_file"
             rm -f "$body_file"
@@ -80,7 +80,7 @@ curl_gitea_pull() {
     fi
 
     if [[ -z "${http_code:-}" ]]; then
-        raw_code=$(curl -sS -w '%{http_code}' -o "$body_file" "$api_url" || true)
+        raw_code=$(curl -sS -w '%{http_code}' -o "$body_file" -H "User-Agent: curl/8" "$api_url" || true)
         http_code="$raw_code"
     fi
 
diff --git a/packages/mosaic/framework/tools/git/pr-review.sh b/packages/mosaic/framework/tools/git/pr-review.sh
index 51c2bb4..35acf9a 100755
--- a/packages/mosaic/framework/tools/git/pr-review.sh
+++ b/packages/mosaic/framework/tools/git/pr-review.sh
@@ -53,7 +53,7 @@ if [[ -z "$ACTION" ]]; then
     exit 1
 fi
 
-detect_platform
+detect_platform >/dev/null
 
 if [[ "$PLATFORM" == "github" ]]; then
     case $ACTION in
diff --git a/packages/mosaic/framework/tools/git/pr-view.sh b/packages/mosaic/framework/tools/git/pr-view.sh
index 25b0d01..8a1283a 100755
--- a/packages/mosaic/framework/tools/git/pr-view.sh
+++ b/packages/mosaic/framework/tools/git/pr-view.sh
@@ -58,7 +58,18 @@ fi
 if [[ "$PLATFORM" == "github" ]]; then
     gh pr view "$PR_NUMBER" --repo "$REPO_INFO"
 elif [[ "$PLATFORM" == "gitea" ]]; then
-    tea pr "$PR_NUMBER" --repo "$REPO_INFO" --login "${GITEA_LOGIN:-mosaicstack}"
+    if [[ -n "$REPO_OVERRIDE" ]]; then
+        GITEA_LOGIN_NAME=$(get_gitea_login_for_repo_override) || {
+            echo "Error: Could not resolve Gitea login for --repo override. Set GITEA_LOGIN or configure a default tea login." >&2
+            exit 1
+        }
+    else
+        GITEA_LOGIN_NAME=$(get_gitea_login) || {
+            echo "Error: Could not resolve Gitea login for remote host" >&2
+            exit 1
+        }
+    fi
+    tea pr "$PR_NUMBER" --repo "$REPO_INFO" --login "$GITEA_LOGIN_NAME"
 else
     echo "Error: Unknown platform"
     exit 1
diff --git a/packages/mosaic/framework/tools/git/test-gitea-login-resolution.sh b/packages/mosaic/framework/tools/git/test-gitea-login-resolution.sh
new file mode 100755
index 0000000..de80dcb
--- /dev/null
+++ b/packages/mosaic/framework/tools/git/test-gitea-login-resolution.sh
@@ -0,0 +1,138 @@
+#!/usr/bin/env bash
+# Regression harness for host-specific Gitea tea login resolution.
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+WORK_DIR="${MOSAIC_TEST_WORK_DIR:-$PWD/.mosaic-test-work/gitea-login-resolution}"
+REPO_DIR="$WORK_DIR/repo"
+BIN_DIR="$WORK_DIR/bin"
+LOG_FILE="$WORK_DIR/calls.log"
+CREDENTIALS_FILE="$WORK_DIR/credentials.json"
+
+rm -rf "$WORK_DIR"
+mkdir -p "$REPO_DIR" "$BIN_DIR"
+
+git -C "$REPO_DIR" init -q
+git -C "$REPO_DIR" remote add origin https://git.uscllc.com/USC/uconnect.git
+
+cat > "$CREDENTIALS_FILE" <<'JSON'
+{
+  "gitea": {
+    "mosaicstack": {
+      "url": "https://git.mosaicstack.dev",
+      "token": "mosaic-token"
+    },
+    "usc": {
+      "url": "https://git.uscllc.com",
+      "token": "usc-token"
+    }
+  }
+}
+JSON
+
+cat > "$BIN_DIR/tea" <<'SH'
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [[ "$*" == "login list --output json" ]]; then
+    cat <<'JSON'
+[
+  {"name":"evil-usc","url":"https://evilgit.uscllc.com","user":"bad.actor"},
+  {"name":"usc","url":"https://git.uscllc.com","user":"jason.woltje"}
+]
+JSON
+    exit 0
+fi
+
+printf 'tea %s\n' "$*" >> "$MOSAIC_TEST_LOG"
+exit 0
+SH
+
+cat > "$BIN_DIR/curl" <<'SH'
+#!/usr/bin/env bash
+set -euo pipefail
+
+printf 'curl %s\n' "$*" >> "$MOSAIC_TEST_LOG"
+printf '{}'
+SH
+
+chmod +x "$BIN_DIR/tea" "$BIN_DIR/curl"
+
+run_in_repo() {
+    (
+        cd "$REPO_DIR"
+        PATH="$BIN_DIR:$PATH" \
+        MOSAIC_CREDENTIALS_FILE="$CREDENTIALS_FILE" \
+        MOSAIC_TEST_LOG="$LOG_FILE" \
+        "$@"
+    )
+}
+
+usc_login=$(run_in_repo bash -c '
+    export GITEA_LOGIN=mosaicstack
+    export GITEA_URL=https://git.mosaicstack.dev
+    source "'"$SCRIPT_DIR"'/detect-platform.sh"
+    get_gitea_login
+')
+if [[ "$usc_login" != "usc" ]]; then
+    echo "Expected USC host to resolve tea login 'usc' despite stale mosaicstack env; got '$usc_login'" >&2
+    exit 1
+fi
+
+usc_login_without_url=$(run_in_repo bash -c '
+    export GITEA_LOGIN=mosaicstack
+    unset GITEA_URL
+    source "'"$SCRIPT_DIR"'/detect-platform.sh"
+    get_gitea_login
+')
+if [[ "$usc_login_without_url" != "usc" ]]; then
+    echo "Expected USC host to ignore unmatched GITEA_LOGIN without URL; got '$usc_login_without_url'" >&2
+    exit 1
+fi
+
+git -C "$REPO_DIR" remote set-url origin https://hermes:token@git.uscllc.com/USC/uconnect.git
+embedded_host=$(run_in_repo bash -c '
+    source "'"$SCRIPT_DIR"'/detect-platform.sh"
+    get_remote_host
+')
+if [[ "$embedded_host" != "git.uscllc.com" ]]; then
+    echo "Expected credential-bearing remote host to strip userinfo; got '$embedded_host'" >&2
+    exit 1
+fi
+git -C "$REPO_DIR" remote set-url origin https://git.uscllc.com/USC/uconnect.git
+
+override_login=$(run_in_repo bash -c '
+    export GITEA_LOGIN=usc
+    source "'"$SCRIPT_DIR"'/detect-platform.sh"
+    get_gitea_login_for_repo_override
+')
+if [[ "$override_login" != "usc" ]]; then
+    echo "Expected --repo override path to honor explicit GITEA_LOGIN; got '$override_login'" >&2
+    exit 1
+fi
+
+git -C "$REPO_DIR" remote set-url origin https://git.mosaicstack.dev/mosaicstack/stack.git
+: > "$LOG_FILE"
+run_in_repo env GITEA_LOGIN=usc "$SCRIPT_DIR/issue-list.sh" --repo USC/uconnect -n 1
+grep -q -- 'tea issues list --repo USC/uconnect --login usc' "$LOG_FILE"
+git -C "$REPO_DIR" remote set-url origin https://git.uscllc.com/USC/uconnect.git
+
+: > "$LOG_FILE"
+run_in_repo "$SCRIPT_DIR/issue-close.sh" -i 42
+grep -q -- 'tea issue close 42 --repo USC/uconnect --login usc' "$LOG_FILE"
+if grep -q -- '--login mosaicstack' "$LOG_FILE"; then
+    echo "issue-close.sh used hardcoded mosaicstack login on USC host" >&2
+    exit 1
+fi
+
+git -C "$REPO_DIR" remote set-url origin https://git.mosaicstack.dev/mosaicstack/stack.git
+: > "$LOG_FILE"
+run_in_repo env GITEA_TOKEN=mosaic-token GITEA_URL=https://git.mosaicstack.dev "$SCRIPT_DIR/issue-close.sh" -i 536
+grep -q -- 'curl .*https://git.mosaicstack.dev/api/v1/repos/mosaicstack/stack/issues/536' "$LOG_FILE"
+if grep -q -- 'tea issue close 536 .*--login mosaicstack' "$LOG_FILE"; then
+    echo "issue-close.sh invented a mosaicstack tea login instead of using API fallback" >&2
+    exit 1
+fi
+
+echo "Gitea login resolution regression harness passed"
diff --git a/packages/mosaic/framework/tools/git/test-pr-merge-gitea-empty-uid.sh b/packages/mosaic/framework/tools/git/test-pr-merge-gitea-empty-uid.sh
index 7be5cb8..9dbf2e2 100755
--- a/packages/mosaic/framework/tools/git/test-pr-merge-gitea-empty-uid.sh
+++ b/packages/mosaic/framework/tools/git/test-pr-merge-gitea-empty-uid.sh
@@ -99,6 +99,7 @@ git remote add origin https://git.mosaicstack.dev/mosaicstack/stack.git
 export PATH="$MOCK_BIN:$PATH"
 export PR_MERGE_TEST_LOG="$LOG_FILE"
 export GITEA_LOGIN="git.mosaicstack.dev"
+export GITEA_URL="https://git.mosaicstack.dev"
 export GITEA_TOKEN="redacted-test-token"
 
 OUTPUT="$SANDBOX/output.log"