From 0bda50c91716b2418220c4fb126f0ef7a9acbcb9 Mon Sep 17 00:00:00 2001
From: kzoeps <kzoepa@gmail.com>
Date: Tue, 10 Nov 2026 16:20:18 +0600
Subject: [PATCH] lua: share one NSID validator across endpoints

Eight endpoints carried private copies of the same NSID check. They accept
identical inputs, so they are replaced by lua/shared/nsidValidation.lua and
added to the eight bundles that use it. Endpoint behavior is unchanged.
---
 .../lua/endpoints/getActorReactions.lua       | 35 ++++++++++---------
 .../lua/endpoints/getEntityFollows.lua        | 34 +++++++++---------
 .../lua/endpoints/getReactionCounts.lua       | 35 ++++++++++---------
 .../lua/endpoints/listAcknowledgements.lua    | 33 ++++++++---------
 .../lua/endpoints/listBadgeAwards.lua         | 35 ++++++++++---------
 .../lua/endpoints/listEvaluations.lua         |  8 ++---
 .../lua/endpoints/listMeasurements.lua        |  7 ++--
 .../lua/endpoints/listReceipts.lua            | 30 +++++++---------
 .../lua/shared/acknowledgementList.lua        | 16 ---------
 .../lua/shared/evaluationList.lua             | 21 -----------
 .../lua/shared/feedActorReactions.lua         | 18 +---------
 .../lua/shared/fundingReceiptList.lua         | 23 +-----------
 .../lua/shared/nsidValidation.lua             | 16 +++++++++
 .../lua/src/getEntityFollows.lua              | 17 ---------
 .../lua/src/getReactionCounts.lua             | 18 +---------
 happyview-modules/lua/src/listBadgeAwards.lua | 18 +---------
 .../lua/src/listMeasurements.lua              | 20 -----------
 .../modules/acknowledgements/manifest.json    |  1 +
 .../modules/badge-queries/manifest.json       |  3 +-
 .../modules/context-evaluation/manifest.json  |  1 +
 .../context-measurements/manifest.json        |  3 +-
 .../modules/entity-follow/manifest.json       |  3 +-
 .../modules/feed-reactions/manifest.json      |  4 ++-
 .../modules/funding/manifest.json             |  1 +
 24 files changed, 137 insertions(+), 263 deletions(-)
 create mode 100644 happyview-modules/lua/shared/nsidValidation.lua

diff --git a/happyview-modules/lua/endpoints/getActorReactions.lua b/happyview-modules/lua/endpoints/getActorReactions.lua
index 717bad3e..dab2fca3 100644
--- a/happyview-modules/lua/endpoints/getActorReactions.lua
+++ b/happyview-modules/lua/endpoints/getActorReactions.lua
@@ -51,6 +51,23 @@ local function record_view(row)
   }
 end
 
+-- An atproto NSID: at least three dot-separated segments, at most 317 characters.
+local function valid_nsid(value)
+  if type(value) ~= "string" or #value > 317 then return false end
+  local segments = {}
+  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
+  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
+  for index = 1, #segments - 1 do
+    local segment = segments[index]
+    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
+    local first, last = segment:sub(1, 1), segment:sub(-1)
+    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
+      or not last:match("^[A-Za-z0-9]$") then return false end
+  end
+  local name = segments[#segments]
+  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
+end
+
 local ACTOR_REACTION_NULL = json.decode("null")
 local ACTOR_REACTION_LIMIT = 100
 local ACTOR_REACTION_COLLECTIONS = {
@@ -67,25 +84,9 @@ local function actor_reaction_sort_key()
     ", 'timestamptz') THEN (" .. created .. ")::timestamptz ELSE COALESCE(indexed_at::timestamptz, created_at::timestamptz) END"
 end
 
-local function valid_actor_reaction_nsid(value)
-  if type(value) ~= "string" or #value > 317 then return false end
-  local segments = {}
-  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
-  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-  for index = 1, #segments - 1 do
-    local segment = segments[index]
-    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
-    local first, last = segment:sub(1, 1), segment:sub(-1)
-    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
-      or not last:match("^[A-Za-z0-9]$") then return false end
-  end
-  local name = segments[#segments]
-  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
-end
-
 local function valid_actor_reaction_subject_uri(value)
   local valid, collection = valid_record_uri(value)
-  return valid and valid_actor_reaction_nsid(collection)
+  return valid and valid_nsid(collection)
 end
 
 local function feed_actor_reaction_subjects(value)
diff --git a/happyview-modules/lua/endpoints/getEntityFollows.lua b/happyview-modules/lua/endpoints/getEntityFollows.lua
index e22319e5..882bb606 100644
--- a/happyview-modules/lua/endpoints/getEntityFollows.lua
+++ b/happyview-modules/lua/endpoints/getEntityFollows.lua
@@ -142,27 +142,27 @@ local function follow_batch_targets(actor, key, value, validate, description, en
   return targets, unique
 end
 
+-- An atproto NSID: at least three dot-separated segments, at most 317 characters.
+local function valid_nsid(value)
+  if type(value) ~= "string" or #value > 317 then return false end
+  local segments = {}
+  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
+  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
+  for index = 1, #segments - 1 do
+    local segment = segments[index]
+    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
+    local first, last = segment:sub(1, 1), segment:sub(-1)
+    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
+      or not last:match("^[A-Za-z0-9]$") then return false end
+  end
+  local name = segments[#segments]
+  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
+end
+
 local function get_entity_follows()
   keys_only(params, { actor = true, entities = true })
   local actor = scalar(params, "actor")
   if not actor or not valid_did(actor) then invalid("actor must be a valid DID") end
-  local function valid_nsid(value)
-    if type(value) ~= "string" or #value > 317 then return false end
-    local segments = {}
-    for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
-    if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-
-    for _, segment in ipairs(segments) do
-      if #segment > 63 or segment:find("[^A-Za-z0-9%-]")
-        or segment:sub(1, 1) == "-" or segment:sub(-1) == "-" then
-        return false
-      end
-    end
-
-    if not segments[1]:sub(1, 1):match("^[A-Za-z]$") then return false end
-    return segments[#segments]:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
-  end
-
   local function valid_entity_uri(value)
     if #value > 8192 then return false end
     local valid, collection = valid_record_uri(value)
diff --git a/happyview-modules/lua/endpoints/getReactionCounts.lua b/happyview-modules/lua/endpoints/getReactionCounts.lua
index 15d19196..311b2728 100644
--- a/happyview-modules/lua/endpoints/getReactionCounts.lua
+++ b/happyview-modules/lua/endpoints/getReactionCounts.lua
@@ -39,6 +39,23 @@ local function valid_record_uri(value)
   return true, collection, authority
 end
 
+-- An atproto NSID: at least three dot-separated segments, at most 317 characters.
+local function valid_nsid(value)
+  if type(value) ~= "string" or #value > 317 then return false end
+  local segments = {}
+  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
+  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
+  for index = 1, #segments - 1 do
+    local segment = segments[index]
+    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
+    local first, last = segment:sub(1, 1), segment:sub(-1)
+    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
+      or not last:match("^[A-Za-z0-9]$") then return false end
+  end
+  local name = segments[#segments]
+  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
+end
+
 local LIKE = "app.certified.feed.like"
 local REPOST = "app.certified.feed.repost"
 
@@ -55,22 +72,6 @@ local function reaction_count_valid_did_percent_escapes(authority)
   return true
 end
 
-local function reaction_count_valid_nsid(value)
-  if type(value) ~= "string" or #value > 317 then return false end
-  local segments = {}
-  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
-  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-  for index = 1, #segments - 1 do
-    local segment = segments[index]
-    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
-    local first, last = segment:sub(1, 1), segment:sub(-1)
-    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
-      or not last:match("^[A-Za-z0-9]$") then return false end
-  end
-  local name = segments[#segments]
-  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
-end
-
 local function reaction_count_subjects()
   local value = params.subjects
   if value == nil then invalid("subjects is required") end
@@ -104,7 +105,7 @@ local function reaction_count_subjects()
   for _, subject in ipairs(supplied) do
     local valid, collection, authority = valid_record_uri(subject)
     if not valid or not reaction_count_valid_did_percent_escapes(authority)
-      or not reaction_count_valid_nsid(collection) then
+      or not valid_nsid(collection) then
       invalid("each subjects value must be a full AT-URI with a valid DID authority and collection NSID")
     end
     if not seen[subject] then
diff --git a/happyview-modules/lua/endpoints/listAcknowledgements.lua b/happyview-modules/lua/endpoints/listAcknowledgements.lua
index 3da756ed..ff6fba61 100644
--- a/happyview-modules/lua/endpoints/listAcknowledgements.lua
+++ b/happyview-modules/lua/endpoints/listAcknowledgements.lua
@@ -130,22 +130,7 @@ local function hydrate_acknowledgement_authors(views)
   end
 end
 
-local generic_valid_datetime = valid_datetime
-
-local function acknowledgement_valid_datetime(value)
-  if type(value) ~= "string" then return false end
-  if value:match("^(%d%d%d%d)") == "0000" then return false end
-  return generic_valid_datetime(value)
-end
-
-local function valid_cursor_timestamp(value)
-  if type(value) ~= "string" or #value ~= 27
-    or not value:match("^%d%d%d%d%-%d%d%-%d%dT%d%d:%d%d:%d%d%.%d%d%d%d%d%dZ$") then
-    return false
-  end
-  return acknowledgement_valid_datetime(value)
-end
-
+-- An atproto NSID: at least three dot-separated segments, at most 317 characters.
 local function valid_nsid(value)
   if type(value) ~= "string" or #value > 317 then return false end
   local segments = {}
@@ -162,6 +147,22 @@ local function valid_nsid(value)
   return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
 end
 
+local generic_valid_datetime = valid_datetime
+
+local function acknowledgement_valid_datetime(value)
+  if type(value) ~= "string" then return false end
+  if value:match("^(%d%d%d%d)") == "0000" then return false end
+  return generic_valid_datetime(value)
+end
+
+local function valid_cursor_timestamp(value)
+  if type(value) ~= "string" or #value ~= 27
+    or not value:match("^%d%d%d%d%-%d%d%-%d%dT%d%d:%d%d:%d%d%.%d%d%d%d%d%dZ$") then
+    return false
+  end
+  return acknowledgement_valid_datetime(value)
+end
+
 local function acknowledgement_array(key, format)
   local value = params[key]
   if value == nil then return nil end
diff --git a/happyview-modules/lua/endpoints/listBadgeAwards.lua b/happyview-modules/lua/endpoints/listBadgeAwards.lua
index 3c615989..b5d0df37 100644
--- a/happyview-modules/lua/endpoints/listBadgeAwards.lua
+++ b/happyview-modules/lua/endpoints/listBadgeAwards.lua
@@ -123,22 +123,8 @@ local function hydrate_actor_views(actors, run_query)
   end
 end
 
-local AWARD = "app.certified.badge.award"
-local DEFINITION = "app.certified.badge.definition"
-local RESPONSE = "app.certified.badge.response"
-local RESPONSE_STATUSES = { accepted = true, rejected = true, unanswered = true }
-
-local function valid_badge_award_uri(value)
-  local valid, collection = valid_record_uri(value)
-  return valid and collection == AWARD
-end
-
-local function valid_badge_definition_uri(value)
-  local valid, collection = valid_record_uri(value)
-  return valid and collection == DEFINITION
-end
-
-local function valid_badge_subject_nsid(value)
+-- An atproto NSID: at least three dot-separated segments, at most 317 characters.
+local function valid_nsid(value)
   if type(value) ~= "string" or #value > 317 then return false end
   local segments = {}
   for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
@@ -154,6 +140,21 @@ local function valid_badge_subject_nsid(value)
   return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
 end
 
+local AWARD = "app.certified.badge.award"
+local DEFINITION = "app.certified.badge.definition"
+local RESPONSE = "app.certified.badge.response"
+local RESPONSE_STATUSES = { accepted = true, rejected = true, unanswered = true }
+
+local function valid_badge_award_uri(value)
+  local valid, collection = valid_record_uri(value)
+  return valid and collection == AWARD
+end
+
+local function valid_badge_definition_uri(value)
+  local valid, collection = valid_record_uri(value)
+  return valid and collection == DEFINITION
+end
+
 local function query(sql, values)
   if db.backend() ~= "postgres" then
     error("BadgeAwardQueryFailed: badge award API requires PostgreSQL", 0)
@@ -205,7 +206,7 @@ local function subject_values()
     local is_did = valid_did(item)
     local valid_uri, collection
     if not is_did then valid_uri, collection = valid_record_uri(item) end
-    if not is_did and (not valid_uri or not valid_badge_subject_nsid(collection)) then
+    if not is_did and (not valid_uri or not valid_nsid(collection)) then
       invalid("subjects[" .. index .. "] must be a valid DID or full record AT-URI with a valid collection NSID")
     end
     if not seen[item] then
diff --git a/happyview-modules/lua/endpoints/listEvaluations.lua b/happyview-modules/lua/endpoints/listEvaluations.lua
index 90126461..c0232b88 100644
--- a/happyview-modules/lua/endpoints/listEvaluations.lua
+++ b/happyview-modules/lua/endpoints/listEvaluations.lua
@@ -206,23 +206,19 @@ local function hydrate_evaluation_views(views)
   end
 end
 
+-- An atproto NSID: at least three dot-separated segments, at most 317 characters.
 local function valid_nsid(value)
   if type(value) ~= "string" or #value > 317 then return false end
-
   local segments = {}
   for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
   if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-
   for index = 1, #segments - 1 do
     local segment = segments[index]
     if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
     local first, last = segment:sub(1, 1), segment:sub(-1)
     if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
-      or not last:match("^[A-Za-z0-9]$") then
-      return false
-    end
+      or not last:match("^[A-Za-z0-9]$") then return false end
   end
-
   local name = segments[#segments]
   return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
 end
diff --git a/happyview-modules/lua/endpoints/listMeasurements.lua b/happyview-modules/lua/endpoints/listMeasurements.lua
index 85f0d628..b1be923d 100644
--- a/happyview-modules/lua/endpoints/listMeasurements.lua
+++ b/happyview-modules/lua/endpoints/listMeasurements.lua
@@ -165,22 +165,19 @@ local function hydrate_measurement_views(views)
   end
 end
 
+-- An atproto NSID: at least three dot-separated segments, at most 317 characters.
 local function valid_nsid(value)
   if type(value) ~= "string" or #value > 317 then return false end
   local segments = {}
   for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
   if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-
   for index = 1, #segments - 1 do
     local segment = segments[index]
     if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
     local first, last = segment:sub(1, 1), segment:sub(-1)
     if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
-      or not last:match("^[A-Za-z0-9]$") then
-      return false
-    end
+      or not last:match("^[A-Za-z0-9]$") then return false end
   end
-
   local name = segments[#segments]
   return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
 end
diff --git a/happyview-modules/lua/endpoints/listReceipts.lua b/happyview-modules/lua/endpoints/listReceipts.lua
index 6c33a906..fa320206 100644
--- a/happyview-modules/lua/endpoints/listReceipts.lua
+++ b/happyview-modules/lua/endpoints/listReceipts.lua
@@ -147,30 +147,26 @@ local function hydrate_funding_receipt_views(views)
   end
 end
 
-local function valid_funding_nsid(value)
-  if type(value) ~= "string" or #value < 5 or #value > 317 or value:find("[^A-Za-z0-9.%-]") then
-    return false
-  end
+-- An atproto NSID: at least three dot-separated segments, at most 317 characters.
+local function valid_nsid(value)
+  if type(value) ~= "string" or #value > 317 then return false end
   local segments = {}
-  for segment in value:gmatch("[^.]+") do segments[#segments + 1] = segment end
+  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
   if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-
-  for index, segment in ipairs(segments) do
-    if #segment > 63 or segment:find("^[%-]") or segment:find("[%-]$") then return false end
-    if index == 1 then
-      if not segment:match("^[A-Za-z]") then return false end
-    elseif index == #segments then
-      if not segment:match("^[A-Za-z][A-Za-z0-9]*$") then return false end
-    elseif not segment:match("^[A-Za-z0-9]") then
-      return false
-    end
+  for index = 1, #segments - 1 do
+    local segment = segments[index]
+    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
+    local first, last = segment:sub(1, 1), segment:sub(-1)
+    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
+      or not last:match("^[A-Za-z0-9]$") then return false end
   end
-  return true
+  local name = segments[#segments]
+  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
 end
 
 local function valid_funding_record_uri(value)
   local valid, collection = valid_record_uri(value)
-  if not valid or not valid_funding_nsid(collection) then return false, collection end
+  if not valid or not valid_nsid(collection) then return false, collection end
   return true, collection
 end
 
diff --git a/happyview-modules/lua/shared/acknowledgementList.lua b/happyview-modules/lua/shared/acknowledgementList.lua
index d57fec01..ef3773e5 100644
--- a/happyview-modules/lua/shared/acknowledgementList.lua
+++ b/happyview-modules/lua/shared/acknowledgementList.lua
@@ -14,22 +14,6 @@ local function valid_cursor_timestamp(value)
   return acknowledgement_valid_datetime(value)
 end
 
-local function valid_nsid(value)
-  if type(value) ~= "string" or #value > 317 then return false end
-  local segments = {}
-  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
-  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-  for index = 1, #segments - 1 do
-    local segment = segments[index]
-    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
-    local first, last = segment:sub(1, 1), segment:sub(-1)
-    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
-      or not last:match("^[A-Za-z0-9]$") then return false end
-  end
-  local name = segments[#segments]
-  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
-end
-
 local function acknowledgement_array(key, format)
   local value = params[key]
   if value == nil then return nil end
diff --git a/happyview-modules/lua/shared/evaluationList.lua b/happyview-modules/lua/shared/evaluationList.lua
index e737b2b0..febddba5 100644
--- a/happyview-modules/lua/shared/evaluationList.lua
+++ b/happyview-modules/lua/shared/evaluationList.lua
@@ -1,24 +1,3 @@
-local function valid_nsid(value)
-  if type(value) ~= "string" or #value > 317 then return false end
-
-  local segments = {}
-  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
-  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-
-  for index = 1, #segments - 1 do
-    local segment = segments[index]
-    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
-    local first, last = segment:sub(1, 1), segment:sub(-1)
-    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
-      or not last:match("^[A-Za-z0-9]$") then
-      return false
-    end
-  end
-
-  local name = segments[#segments]
-  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
-end
-
 local function evaluation_array(key, format)
   local value = params[key]
   if value == nil then return nil end
diff --git a/happyview-modules/lua/shared/feedActorReactions.lua b/happyview-modules/lua/shared/feedActorReactions.lua
index 9e27defa..578ff264 100644
--- a/happyview-modules/lua/shared/feedActorReactions.lua
+++ b/happyview-modules/lua/shared/feedActorReactions.lua
@@ -14,25 +14,9 @@ local function actor_reaction_sort_key()
     ", 'timestamptz') THEN (" .. created .. ")::timestamptz ELSE COALESCE(indexed_at::timestamptz, created_at::timestamptz) END"
 end
 
-local function valid_actor_reaction_nsid(value)
-  if type(value) ~= "string" or #value > 317 then return false end
-  local segments = {}
-  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
-  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-  for index = 1, #segments - 1 do
-    local segment = segments[index]
-    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
-    local first, last = segment:sub(1, 1), segment:sub(-1)
-    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
-      or not last:match("^[A-Za-z0-9]$") then return false end
-  end
-  local name = segments[#segments]
-  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
-end
-
 local function valid_actor_reaction_subject_uri(value)
   local valid, collection = valid_record_uri(value)
-  return valid and valid_actor_reaction_nsid(collection)
+  return valid and valid_nsid(collection)
 end
 
 local function feed_actor_reaction_subjects(value)
diff --git a/happyview-modules/lua/shared/fundingReceiptList.lua b/happyview-modules/lua/shared/fundingReceiptList.lua
index 8fddb8dc..263b9655 100644
--- a/happyview-modules/lua/shared/fundingReceiptList.lua
+++ b/happyview-modules/lua/shared/fundingReceiptList.lua
@@ -1,27 +1,6 @@
-local function valid_funding_nsid(value)
-  if type(value) ~= "string" or #value < 5 or #value > 317 or value:find("[^A-Za-z0-9.%-]") then
-    return false
-  end
-  local segments = {}
-  for segment in value:gmatch("[^.]+") do segments[#segments + 1] = segment end
-  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-
-  for index, segment in ipairs(segments) do
-    if #segment > 63 or segment:find("^[%-]") or segment:find("[%-]$") then return false end
-    if index == 1 then
-      if not segment:match("^[A-Za-z]") then return false end
-    elseif index == #segments then
-      if not segment:match("^[A-Za-z][A-Za-z0-9]*$") then return false end
-    elseif not segment:match("^[A-Za-z0-9]") then
-      return false
-    end
-  end
-  return true
-end
-
 local function valid_funding_record_uri(value)
   local valid, collection = valid_record_uri(value)
-  if not valid or not valid_funding_nsid(collection) then return false, collection end
+  if not valid or not valid_nsid(collection) then return false, collection end
   return true, collection
 end
 
diff --git a/happyview-modules/lua/shared/nsidValidation.lua b/happyview-modules/lua/shared/nsidValidation.lua
new file mode 100644
index 00000000..e7bd55a4
--- /dev/null
+++ b/happyview-modules/lua/shared/nsidValidation.lua
@@ -0,0 +1,16 @@
+-- An atproto NSID: at least three dot-separated segments, at most 317 characters.
+local function valid_nsid(value)
+  if type(value) ~= "string" or #value > 317 then return false end
+  local segments = {}
+  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
+  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
+  for index = 1, #segments - 1 do
+    local segment = segments[index]
+    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
+    local first, last = segment:sub(1, 1), segment:sub(-1)
+    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
+      or not last:match("^[A-Za-z0-9]$") then return false end
+  end
+  local name = segments[#segments]
+  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
+end
diff --git a/happyview-modules/lua/src/getEntityFollows.lua b/happyview-modules/lua/src/getEntityFollows.lua
index 148059d1..d2f3cde3 100644
--- a/happyview-modules/lua/src/getEntityFollows.lua
+++ b/happyview-modules/lua/src/getEntityFollows.lua
@@ -2,23 +2,6 @@ local function get_entity_follows()
   keys_only(params, { actor = true, entities = true })
   local actor = scalar(params, "actor")
   if not actor or not valid_did(actor) then invalid("actor must be a valid DID") end
-  local function valid_nsid(value)
-    if type(value) ~= "string" or #value > 317 then return false end
-    local segments = {}
-    for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
-    if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-
-    for _, segment in ipairs(segments) do
-      if #segment > 63 or segment:find("[^A-Za-z0-9%-]")
-        or segment:sub(1, 1) == "-" or segment:sub(-1) == "-" then
-        return false
-      end
-    end
-
-    if not segments[1]:sub(1, 1):match("^[A-Za-z]$") then return false end
-    return segments[#segments]:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
-  end
-
   local function valid_entity_uri(value)
     if #value > 8192 then return false end
     local valid, collection = valid_record_uri(value)
diff --git a/happyview-modules/lua/src/getReactionCounts.lua b/happyview-modules/lua/src/getReactionCounts.lua
index 369219d1..8187425e 100644
--- a/happyview-modules/lua/src/getReactionCounts.lua
+++ b/happyview-modules/lua/src/getReactionCounts.lua
@@ -14,22 +14,6 @@ local function reaction_count_valid_did_percent_escapes(authority)
   return true
 end
 
-local function reaction_count_valid_nsid(value)
-  if type(value) ~= "string" or #value > 317 then return false end
-  local segments = {}
-  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
-  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-  for index = 1, #segments - 1 do
-    local segment = segments[index]
-    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
-    local first, last = segment:sub(1, 1), segment:sub(-1)
-    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
-      or not last:match("^[A-Za-z0-9]$") then return false end
-  end
-  local name = segments[#segments]
-  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
-end
-
 local function reaction_count_subjects()
   local value = params.subjects
   if value == nil then invalid("subjects is required") end
@@ -63,7 +47,7 @@ local function reaction_count_subjects()
   for _, subject in ipairs(supplied) do
     local valid, collection, authority = valid_record_uri(subject)
     if not valid or not reaction_count_valid_did_percent_escapes(authority)
-      or not reaction_count_valid_nsid(collection) then
+      or not valid_nsid(collection) then
       invalid("each subjects value must be a full AT-URI with a valid DID authority and collection NSID")
     end
     if not seen[subject] then
diff --git a/happyview-modules/lua/src/listBadgeAwards.lua b/happyview-modules/lua/src/listBadgeAwards.lua
index 79b2adbb..0ec48fec 100644
--- a/happyview-modules/lua/src/listBadgeAwards.lua
+++ b/happyview-modules/lua/src/listBadgeAwards.lua
@@ -13,22 +13,6 @@ local function valid_badge_definition_uri(value)
   return valid and collection == DEFINITION
 end
 
-local function valid_badge_subject_nsid(value)
-  if type(value) ~= "string" or #value > 317 then return false end
-  local segments = {}
-  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
-  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-  for index = 1, #segments - 1 do
-    local segment = segments[index]
-    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
-    local first, last = segment:sub(1, 1), segment:sub(-1)
-    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
-      or not last:match("^[A-Za-z0-9]$") then return false end
-  end
-  local name = segments[#segments]
-  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
-end
-
 local function query(sql, values)
   if db.backend() ~= "postgres" then
     error("BadgeAwardQueryFailed: badge award API requires PostgreSQL", 0)
@@ -80,7 +64,7 @@ local function subject_values()
     local is_did = valid_did(item)
     local valid_uri, collection
     if not is_did then valid_uri, collection = valid_record_uri(item) end
-    if not is_did and (not valid_uri or not valid_badge_subject_nsid(collection)) then
+    if not is_did and (not valid_uri or not valid_nsid(collection)) then
       invalid("subjects[" .. index .. "] must be a valid DID or full record AT-URI with a valid collection NSID")
     end
     if not seen[item] then
diff --git a/happyview-modules/lua/src/listMeasurements.lua b/happyview-modules/lua/src/listMeasurements.lua
index 053dc79d..5f6143f1 100644
--- a/happyview-modules/lua/src/listMeasurements.lua
+++ b/happyview-modules/lua/src/listMeasurements.lua
@@ -1,23 +1,3 @@
-local function valid_nsid(value)
-  if type(value) ~= "string" or #value > 317 then return false end
-  local segments = {}
-  for segment in value:gmatch("[^%.]+") do segments[#segments + 1] = segment end
-  if #segments < 3 or table.concat(segments, ".") ~= value then return false end
-
-  for index = 1, #segments - 1 do
-    local segment = segments[index]
-    if #segment > 63 or segment:find("[^A-Za-z0-9%-]") then return false end
-    local first, last = segment:sub(1, 1), segment:sub(-1)
-    if not first:match(index == 1 and "^[A-Za-z]$" or "^[A-Za-z0-9]$")
-      or not last:match("^[A-Za-z0-9]$") then
-      return false
-    end
-  end
-
-  local name = segments[#segments]
-  return #name <= 63 and name:match("^[A-Za-z][A-Za-z0-9]*$") ~= nil
-end
-
 local function measurement_array(key, format)
   local value = params[key]
   if value == nil then return nil end
diff --git a/happyview-modules/modules/acknowledgements/manifest.json b/happyview-modules/modules/acknowledgements/manifest.json
index 847e4231..4ae64fd3 100644
--- a/happyview-modules/modules/acknowledgements/manifest.json
+++ b/happyview-modules/modules/acknowledgements/manifest.json
@@ -67,6 +67,7 @@
         "../../lua/shared/datetimeValidation.lua",
         "../../lua/shared/listValidation.lua",
         "../../lua/shared/acknowledgement.lua",
+        "../../lua/shared/nsidValidation.lua",
         "../../lua/shared/acknowledgementList.lua"
       ],
       "config": {
diff --git a/happyview-modules/modules/badge-queries/manifest.json b/happyview-modules/modules/badge-queries/manifest.json
index d9094381..04b597b8 100644
--- a/happyview-modules/modules/badge-queries/manifest.json
+++ b/happyview-modules/modules/badge-queries/manifest.json
@@ -107,7 +107,8 @@
         "../../lua/shared/listValidation.lua",
         "../../lua/shared/listQuery.lua",
         "../../lua/shared/recordView.lua",
-        "../../lua/shared/actorView.lua"
+        "../../lua/shared/actorView.lua",
+        "../../lua/shared/nsidValidation.lua"
       ],
       "config": {
         "script_type": "lua",
diff --git a/happyview-modules/modules/context-evaluation/manifest.json b/happyview-modules/modules/context-evaluation/manifest.json
index 88ed89a6..e0b0c434 100644
--- a/happyview-modules/modules/context-evaluation/manifest.json
+++ b/happyview-modules/modules/context-evaluation/manifest.json
@@ -54,6 +54,7 @@
         "../../lua/shared/recordView.lua",
         "../../lua/shared/actorView.lua",
         "../../lua/shared/evaluation.lua",
+        "../../lua/shared/nsidValidation.lua",
         "../../lua/shared/evaluationList.lua"
       ],
       "config": {
diff --git a/happyview-modules/modules/context-measurements/manifest.json b/happyview-modules/modules/context-measurements/manifest.json
index 8bc0c670..99a5e3b7 100644
--- a/happyview-modules/modules/context-measurements/manifest.json
+++ b/happyview-modules/modules/context-measurements/manifest.json
@@ -53,7 +53,8 @@
         "../../lua/shared/listQuery.lua",
         "../../lua/shared/recordView.lua",
         "../../lua/shared/actorView.lua",
-        "../../lua/shared/measurementQuery.lua"
+        "../../lua/shared/measurementQuery.lua",
+        "../../lua/shared/nsidValidation.lua"
       ],
       "config": {
         "script_type": "lua"
diff --git a/happyview-modules/modules/entity-follow/manifest.json b/happyview-modules/modules/entity-follow/manifest.json
index 870ea335..b9af0b0d 100644
--- a/happyview-modules/modules/entity-follow/manifest.json
+++ b/happyview-modules/modules/entity-follow/manifest.json
@@ -73,7 +73,8 @@
         "../../lua/shared/query.lua",
         "../../lua/shared/recordIdentifier.lua",
         "../../lua/shared/entityFollow.lua",
-        "../../lua/shared/followBatch.lua"
+        "../../lua/shared/followBatch.lua",
+        "../../lua/shared/nsidValidation.lua"
       ],
       "config": {
         "script_type": "lua",
diff --git a/happyview-modules/modules/feed-reactions/manifest.json b/happyview-modules/modules/feed-reactions/manifest.json
index 905d2513..ecb0b51c 100644
--- a/happyview-modules/modules/feed-reactions/manifest.json
+++ b/happyview-modules/modules/feed-reactions/manifest.json
@@ -142,6 +142,7 @@
         "../../lua/shared/query.lua",
         "../../lua/shared/recordIdentifier.lua",
         "../../lua/shared/recordView.lua",
+        "../../lua/shared/nsidValidation.lua",
         "../../lua/shared/feedActorReactions.lua"
       ],
       "config": { "script_type": "lua", "description": "Actor feed reaction API handler" },
@@ -155,7 +156,8 @@
       "sharedSourcePaths": [
         "../../lua/shared/didValidation.lua",
         "../../lua/shared/query.lua",
-        "../../lua/shared/recordIdentifier.lua"
+        "../../lua/shared/recordIdentifier.lua",
+        "../../lua/shared/nsidValidation.lua"
       ],
       "config": {
         "script_type": "lua",
diff --git a/happyview-modules/modules/funding/manifest.json b/happyview-modules/modules/funding/manifest.json
index dfb6e92b..a1dae3f8 100644
--- a/happyview-modules/modules/funding/manifest.json
+++ b/happyview-modules/modules/funding/manifest.json
@@ -53,6 +53,7 @@
         "../../lua/shared/recordView.lua",
         "../../lua/shared/actorView.lua",
         "../../lua/shared/fundingReceipt.lua",
+        "../../lua/shared/nsidValidation.lua",
         "../../lua/shared/fundingReceiptList.lua"
       ],
       "config": {