[feature] Add from: search operator and account_id query param (#2943)

* Add from: search operator

* Fix whitespace in Swagger YAML comment

* Move query parsing into its own method

* Document search

* Clarify post search scope

11 files changed, 312 insertions, 15 deletions

diff --git a/docs/api/swagger.yaml b/docs/api/swagger.yaml
index a83ea643a..78725f325 100644
--- a/docs/api/swagger.yaml
+++ b/docs/api/swagger.yaml
@@ -2872,6 +2872,9 @@ paths:
                     - `https://example.org/some/arbitrary/url` -- search for an account OR a status with the given URL. Will only ever return 1 result at most.
                     - `#[hashtag_name]` -- search for a hashtag with the given hashtag name, or starting with the given hashtag name. Case insensitive. Can return multiple results.
                     - any arbitrary string -- search for accounts or statuses containing the given string. Can return multiple results.
+
+                    Arbitrary string queries may include the following operators:
+                    - `from:localuser`, `from:remoteuser@instance.tld`: restrict results to statuses created by the specified account.
                   in: query
                   name: q
                   required: true
@@ -2902,6 +2905,10 @@ paths:
                   in: query
                   name: exclude_unreviewed
                   type: boolean
+                - description: Restrict results to statuses created by the specified account.
+                  in: query
+                  name: account_id
+                  type: string
             produces:
                 - application/json
             responses:
diff --git a/docs/user_guide/search.md b/docs/user_guide/search.md
new file mode 100644
index 000000000..a6bf2cbea
--- /dev/null
+++ b/docs/user_guide/search.md
@@ -0,0 +1,20 @@
+# Search
+
+## Query formats
+
+GotoSocial accepts several kinds of search query:
+
+- `@username`: search for an account with the given username on any domain. Can return multiple results.
+- `@username@domain`: search for a remote account with exact username and domain. Will only ever return 1 result at most.
+- `https://example.org/some/arbitrary/url`: search for an account or post with the given URL. If the account or post hasn't already federated to GotoSocial, it will try to retrieve it. Will only ever return 1 result at most.
+- `#hashtag_name`: search for a hashtag with the given hashtag name, or starting with the given hashtag name. Case insensitive. Can return multiple results.
+- `any arbitrary text`: search for posts containing the text, hashtags containing the text, and accounts with usernames, display names, or bios containing the text, exactly as written. Both posts you've written as well as posts replying to you will be searched. Account bios will only be searched for accounts that you follow. Can return multiple results.
+
+## Search operators
+
+Arbitrary text queries may include the following search operators:
+
+- `from:username`: restrict results to statuses created by the specified *local* account.
+- `from:username@domain`: restrict results to statuses created by the specified remote account.
+
+For example, you can search for `sloth from:yourusername` to find your own posts about sloths.
diff --git a/internal/api/client/search/searchget.go b/internal/api/client/search/searchget.go
index 76cb929bf..d7ab81388 100644
--- a/internal/api/client/search/searchget.go
+++ b/internal/api/client/search/searchget.go
@@ -99,6 +99,9 @@ import (
 //			- `https://example.org/some/arbitrary/url` -- search for an account OR a status with the given URL. Will only ever return 1 result at most.
 //			- `#[hashtag_name]` -- search for a hashtag with the given hashtag name, or starting with the given hashtag name. Case insensitive. Can return multiple results.
 //			- any arbitrary string -- search for accounts or statuses containing the given string. Can return multiple results.
+//
+//			Arbitrary string queries may include the following operators:
+//			- `from:localuser`, `from:remoteuser@instance.tld`: restrict results to statuses created by the specified account.
 //		in: query
 //		required: true
 //	-
@@ -138,6 +141,12 @@ import (
 //			Currently this parameter is unused.
 //		default: false
 //		in: query
+//	-
+//		name: account_id
+//		type: string
+//		description: >-
+//			Restrict results to statuses created by the specified account.
+//		in: query
 //
 //	security:
 //	- OAuth2 Bearer:
@@ -238,6 +247,7 @@ func (m *Module) SearchGETHandler(c *gin.Context) {
 		Resolve:           resolve,
 		Following:         following,
 		ExcludeUnreviewed: excludeUnreviewed,
+		AccountID:         c.Query(apiutil.SearchAccountIDKey),
 		APIv1:             apiVersion == apiutil.APIv1,
 	}
 
diff --git a/internal/api/client/search/searchget_test.go b/internal/api/client/search/searchget_test.go
index 1b4b92c21..a0d0cad0e 100644
--- a/internal/api/client/search/searchget_test.go
+++ b/internal/api/client/search/searchget_test.go
@@ -60,6 +60,7 @@ func (suite *SearchGetTestSuite) getSearch(
 	queryType *string,
 	resolve *bool,
 	following *bool,
+	fromAccountID *string,
 	expectedHTTPStatus int,
 	expectedBody string,
 ) (*apimodel.SearchResult, error) {
@@ -103,6 +104,10 @@ func (suite *SearchGetTestSuite) getSearch(
 		queryParts = append(queryParts, apiutil.SearchFollowingKey+"="+strconv.FormatBool(*following))
 	}
 
+	if fromAccountID != nil {
+		queryParts = append(queryParts, apiutil.SearchAccountIDKey+"="+url.QueryEscape(*fromAccountID))
+	}
+
 	requestURL.RawQuery = strings.Join(queryParts, "&")
 	ctx.Request = httptest.NewRequest(http.MethodGet, requestURL.String(), nil)
 	ctx.Set(oauth.SessionAuthorizedAccount, requestingAccount)
@@ -174,6 +179,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByURI() {
 		query                      = "https://unknown-instance.com/users/brand_new_person"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -191,6 +197,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByURI() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -218,6 +225,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByNamestring() {
 		query                      = "@brand_new_person@unknown-instance.com"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -235,6 +243,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByNamestring() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -262,6 +271,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByNamestringUppercase()
 		query                      = "@Some_User@example.org"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -279,6 +289,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByNamestringUppercase()
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -306,6 +317,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByNamestringNoLeadingAt(
 		query                      = "brand_new_person@unknown-instance.com"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -323,6 +335,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByNamestringNoLeadingAt(
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -350,6 +363,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByNamestringNoResolve()
 		query                      = "@brand_new_person@unknown-instance.com"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -367,6 +381,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByNamestringNoResolve()
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -389,6 +404,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByNamestringSpecialChars
 		query                      = "@üser@ëxample.org"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -406,6 +422,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByNamestringSpecialChars
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -431,6 +448,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByNamestringSpecialChars
 		query                      = "@üser@xn--xample-ova.org"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -448,6 +466,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteAccountByNamestringSpecialChars
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -473,6 +492,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalAccountByNamestring() {
 		query                      = "@the_mighty_zork"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -490,6 +510,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalAccountByNamestring() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -517,6 +538,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalAccountByNamestringWithDomain()
 		query                      = "@the_mighty_zork@localhost:8080"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -534,6 +556,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalAccountByNamestringWithDomain()
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -561,6 +584,7 @@ func (suite *SearchGetTestSuite) TestSearchNonexistingLocalAccountByNamestringRe
 		query                      = "@somone_made_up@localhost:8080"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -578,6 +602,7 @@ func (suite *SearchGetTestSuite) TestSearchNonexistingLocalAccountByNamestringRe
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -600,6 +625,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalAccountByURI() {
 		query                      = "http://localhost:8080/users/the_mighty_zork"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -617,6 +643,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalAccountByURI() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -644,6 +671,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalAccountByURL() {
 		query                      = "http://localhost:8080/@the_mighty_zork"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -661,6 +689,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalAccountByURL() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -688,6 +717,7 @@ func (suite *SearchGetTestSuite) TestSearchNonexistingLocalAccountByURL() {
 		query                      = "http://localhost:8080/@the_shmighty_shmork"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -705,6 +735,7 @@ func (suite *SearchGetTestSuite) TestSearchNonexistingLocalAccountByURL() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -727,6 +758,7 @@ func (suite *SearchGetTestSuite) TestSearchStatusByURL() {
 		query                      = "https://turnip.farm/users/turniplover6969/statuses/70c53e54-3146-42d5-a630-83c8b6c7c042"
 		queryType          *string = func() *string { i := "statuses"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -744,6 +776,7 @@ func (suite *SearchGetTestSuite) TestSearchStatusByURL() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -771,6 +804,7 @@ func (suite *SearchGetTestSuite) TestSearchBlockedDomainURL() {
 		query                      = "https://replyguys.com/@someone"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -788,6 +822,7 @@ func (suite *SearchGetTestSuite) TestSearchBlockedDomainURL() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -812,6 +847,7 @@ func (suite *SearchGetTestSuite) TestSearchBlockedDomainNamestring() {
 		query                      = "@someone@replyguys.com"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -829,6 +865,7 @@ func (suite *SearchGetTestSuite) TestSearchBlockedDomainNamestring() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -853,6 +890,7 @@ func (suite *SearchGetTestSuite) TestSearchAAny() {
 		query                      = "a"
 		queryType          *string = nil // Return anything.
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -870,6 +908,7 @@ func (suite *SearchGetTestSuite) TestSearchAAny() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -894,6 +933,7 @@ func (suite *SearchGetTestSuite) TestSearchAAnyFollowingOnly() {
 		query                      = "a"
 		queryType          *string = nil // Return anything.
 		following          *bool   = func() *bool { i := true; return &i }()
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -911,6 +951,7 @@ func (suite *SearchGetTestSuite) TestSearchAAnyFollowingOnly() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -935,6 +976,7 @@ func (suite *SearchGetTestSuite) TestSearchAStatuses() {
 		query                      = "a"
 		queryType          *string = func() *string { i := "statuses"; return &i }() // Only statuses.
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -952,6 +994,7 @@ func (suite *SearchGetTestSuite) TestSearchAStatuses() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -963,6 +1006,92 @@ func (suite *SearchGetTestSuite) TestSearchAStatuses() {
 	suite.Len(searchResult.Hashtags, 0)
 }
 
+func (suite *SearchGetTestSuite) TestSearchHiStatusesWithAccountIDInQueryParam() {
+	var (
+		requestingAccount          = suite.testAccounts["local_account_1"]
+		token                      = suite.testTokens["local_account_1"]
+		user                       = suite.testUsers["local_account_1"]
+		maxID              *string = nil
+		minID              *string = nil
+		limit              *int    = nil
+		offset             *int    = nil
+		resolve            *bool   = func() *bool { i := true; return &i }()
+		query                      = "hi"
+		queryType          *string = func() *string { i := "statuses"; return &i }() // Only statuses.
+		following          *bool   = nil
+		fromAccountID      *string = func() *string { i := suite.testAccounts["local_account_2"].ID; return &i }()
+		expectedHTTPStatus         = http.StatusOK
+		expectedBody               = ""
+	)
+
+	searchResult, err := suite.getSearch(
+		requestingAccount,
+		token,
+		apiutil.APIv2,
+		user,
+		maxID,
+		minID,
+		limit,
+		offset,
+		query,
+		queryType,
+		resolve,
+		following,
+		fromAccountID,
+		expectedHTTPStatus,
+		expectedBody)
+	if err != nil {
+		suite.FailNow(err.Error())
+	}
+
+	suite.Len(searchResult.Accounts, 0)
+	suite.Len(searchResult.Statuses, 1)
+	suite.Len(searchResult.Hashtags, 0)
+}
+
+func (suite *SearchGetTestSuite) TestSearchHiStatusesWithAccountIDInQueryText() {
+	var (
+		requestingAccount          = suite.testAccounts["local_account_1"]
+		token                      = suite.testTokens["local_account_1"]
+		user                       = suite.testUsers["local_account_1"]
+		maxID              *string = nil
+		minID              *string = nil
+		limit              *int    = nil
+		offset             *int    = nil
+		resolve            *bool   = func() *bool { i := true; return &i }()
+		query                      = "hi from:1happyturtle"
+		queryType          *string = func() *string { i := "statuses"; return &i }() // Only statuses.
+		following          *bool   = nil
+		fromAccountID      *string = nil
+		expectedHTTPStatus         = http.StatusOK
+		expectedBody               = ""
+	)
+
+	searchResult, err := suite.getSearch(
+		requestingAccount,
+		token,
+		apiutil.APIv2,
+		user,
+		maxID,
+		minID,
+		limit,
+		offset,
+		query,
+		queryType,
+		resolve,
+		following,
+		fromAccountID,
+		expectedHTTPStatus,
+		expectedBody)
+	if err != nil {
+		suite.FailNow(err.Error())
+	}
+
+	suite.Len(searchResult.Accounts, 0)
+	suite.Len(searchResult.Statuses, 1)
+	suite.Len(searchResult.Hashtags, 0)
+}
+
 func (suite *SearchGetTestSuite) TestSearchAAccounts() {
 	var (
 		requestingAccount          = suite.testAccounts["local_account_1"]
@@ -976,6 +1105,7 @@ func (suite *SearchGetTestSuite) TestSearchAAccounts() {
 		query                      = "a"
 		queryType          *string = func() *string { i := "accounts"; return &i }() // Only accounts.
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -993,6 +1123,7 @@ func (suite *SearchGetTestSuite) TestSearchAAccounts() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1017,6 +1148,7 @@ func (suite *SearchGetTestSuite) TestSearchAccountsLimit1() {
 		query                      = "a"
 		queryType          *string = func() *string { i := "accounts"; return &i }() // Only accounts.
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -1034,6 +1166,7 @@ func (suite *SearchGetTestSuite) TestSearchAccountsLimit1() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1058,6 +1191,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalInstanceAccountByURI() {
 		query                      = "http://localhost:8080/users/localhost:8080"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -1075,6 +1209,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalInstanceAccountByURI() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1107,6 +1242,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalInstanceAccountFull() {
 		query                      = "@" + newDomain + "@" + newDomain
 		queryType          *string = nil
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -1124,6 +1260,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalInstanceAccountFull() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1156,6 +1293,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalInstanceAccountPartial() {
 		query                      = "@" + newDomain
 		queryType          *string = nil
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -1173,6 +1311,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalInstanceAccountPartial() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1206,6 +1345,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalInstanceAccountEvenMorePartial()
 		query                      = newDomain
 		queryType          *string = nil
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -1223,6 +1363,7 @@ func (suite *SearchGetTestSuite) TestSearchLocalInstanceAccountEvenMorePartial()
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1280,6 +1421,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteInstanceAccountPartial() {
 		query                      = "@" + theirDomain
 		queryType          *string = nil
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -1297,6 +1439,7 @@ func (suite *SearchGetTestSuite) TestSearchRemoteInstanceAccountPartial() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1323,6 +1466,7 @@ func (suite *SearchGetTestSuite) TestSearchBadQueryType() {
 		query                      = "whatever"
 		queryType          *string = func() *string { i := "aaaaaaaaaaa"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusBadRequest
 		expectedBody               = `{"error":"Bad Request: search query type aaaaaaaaaaa was not recognized, valid options are ['', 'accounts', 'statuses', 'hashtags']"}`
 	)
@@ -1340,6 +1484,7 @@ func (suite *SearchGetTestSuite) TestSearchBadQueryType() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1360,6 +1505,7 @@ func (suite *SearchGetTestSuite) TestSearchEmptyQuery() {
 		query                      = ""
 		queryType          *string = func() *string { i := "aaaaaaaaaaa"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusBadRequest
 		expectedBody               = `{"error":"Bad Request: required key q was not set or had empty value"}`
 	)
@@ -1377,6 +1523,7 @@ func (suite *SearchGetTestSuite) TestSearchEmptyQuery() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1397,6 +1544,7 @@ func (suite *SearchGetTestSuite) TestSearchHashtagV1() {
 		query                      = "#welcome"
 		queryType          *string = func() *string { i := "hashtags"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = `{"accounts":[],"statuses":[],"hashtags":[{"name":"welcome","url":"http://localhost:8080/tags/welcome","history":[]}]}`
 	)
@@ -1414,6 +1562,7 @@ func (suite *SearchGetTestSuite) TestSearchHashtagV1() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1438,6 +1587,7 @@ func (suite *SearchGetTestSuite) TestSearchHashtagV2() {
 		query                      = "#welcome"
 		queryType          *string = func() *string { i := "hashtags"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = `{"accounts":[],"statuses":[],"hashtags":["welcome"]}`
 	)
@@ -1455,6 +1605,7 @@ func (suite *SearchGetTestSuite) TestSearchHashtagV2() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1479,6 +1630,7 @@ func (suite *SearchGetTestSuite) TestSearchHashtagButWithAccountSearch() {
 		query                      = "#welcome"
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ``
 	)
@@ -1496,6 +1648,7 @@ func (suite *SearchGetTestSuite) TestSearchHashtagButWithAccountSearch() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1520,6 +1673,7 @@ func (suite *SearchGetTestSuite) TestSearchNotHashtagButWithTypeHashtag() {
 		query                      = "welco"
 		queryType          *string = func() *string { i := "hashtags"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ``
 	)
@@ -1537,6 +1691,7 @@ func (suite *SearchGetTestSuite) TestSearchNotHashtagButWithTypeHashtag() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1562,6 +1717,7 @@ func (suite *SearchGetTestSuite) TestSearchBlockedAccountFullNamestring() {
 		query                      = "@" + targetAccount.Username + "@" + targetAccount.Domain
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -1593,6 +1749,7 @@ func (suite *SearchGetTestSuite) TestSearchBlockedAccountFullNamestring() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1624,6 +1781,7 @@ func (suite *SearchGetTestSuite) TestSearchBlockedAccountPartialNamestring() {
 		query                      = "@" + targetAccount.Username
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -1655,6 +1813,7 @@ func (suite *SearchGetTestSuite) TestSearchBlockedAccountPartialNamestring() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
@@ -1683,6 +1842,7 @@ func (suite *SearchGetTestSuite) TestSearchBlockedAccountURI() {
 		query                      = targetAccount.URI
 		queryType          *string = func() *string { i := "accounts"; return &i }()
 		following          *bool   = nil
+		fromAccountID      *string = nil
 		expectedHTTPStatus         = http.StatusOK
 		expectedBody               = ""
 	)
@@ -1714,6 +1874,7 @@ func (suite *SearchGetTestSuite) TestSearchBlockedAccountURI() {
 		queryType,
 		resolve,
 		following,
+		fromAccountID,
 		expectedHTTPStatus,
 		expectedBody)
 	if err != nil {
diff --git a/internal/api/model/search.go b/internal/api/model/search.go
index 738c5911f..d16863c9c 100644
--- a/internal/api/model/search.go
+++ b/internal/api/model/search.go
@@ -28,6 +28,7 @@ type SearchRequest struct {
 	Resolve           bool
 	Following         bool
 	ExcludeUnreviewed bool
+	AccountID         string
 	APIv1             bool // Set to 'true' if using version 1 of the search API.
 }
 
diff --git a/internal/api/util/parsequery.go b/internal/api/util/parsequery.go
index 54cb4c466..5210735a1 100644
--- a/internal/api/util/parsequery.go
+++ b/internal/api/util/parsequery.go
@@ -55,6 +55,7 @@ const (
 	SearchQueryKey             = "q"
 	SearchResolveKey           = "resolve"
 	SearchTypeKey              = "type"
+	SearchAccountIDKey         = "account_id"
 
 	/* Tag keys */
 
diff --git a/internal/db/bundb/search.go b/internal/db/bundb/search.go
index f8ae529f7..e54cb78e7 100644
--- a/internal/db/bundb/search.go
+++ b/internal/db/bundb/search.go
@@ -266,8 +266,9 @@ func (s *searchDB) accountText(following bool) *bun.SelectQuery {
 //	ORDER BY "status"."id" DESC LIMIT 10
 func (s *searchDB) SearchForStatuses(
 	ctx context.Context,
-	accountID string,
+	requestingAccountID string,
 	query string,
+	fromAccountID string,
 	maxID string,
 	minID string,
 	limit int,
@@ -295,9 +296,12 @@ func (s *searchDB) SearchForStatuses(
 		// accountID or replying to accountID.
 		WhereGroup(" AND ", func(q *bun.SelectQuery) *bun.SelectQuery {
 			return q.
-				Where("? = ?", bun.Ident("status.account_id"), accountID).
-				WhereOr("? = ?", bun.Ident("status.in_reply_to_account_id"), accountID)
+				Where("? = ?", bun.Ident("status.account_id"), requestingAccountID).
+				WhereOr("? = ?", bun.Ident("status.in_reply_to_account_id"), requestingAccountID)
 		})
+	if fromAccountID != "" {
+		q = q.Where("? = ?", bun.Ident("status.account_id"), fromAccountID)
+	}
 
 	// Return only items with a LOWER id than maxID.
 	if maxID == "" {
diff --git a/internal/db/bundb/search_test.go b/internal/db/bundb/search_test.go
index 75a2d8c8e..cf24b2881 100644
--- a/internal/db/bundb/search_test.go
+++ b/internal/db/bundb/search_test.go
@@ -107,11 +107,22 @@ func (suite *SearchTestSuite) TestSearchAccountsFossAny() {
 func (suite *SearchTestSuite) TestSearchStatuses() {
 	testAccount := suite.testAccounts["local_account_1"]
 
-	statuses, err := suite.db.SearchForStatuses(context.Background(), testAccount.ID, "hello", "", "", 10, 0)
+	statuses, err := suite.db.SearchForStatuses(context.Background(), testAccount.ID, "hello", "", "", "", 10, 0)
 	suite.NoError(err)
 	suite.Len(statuses, 1)
 }
 
+func (suite *SearchTestSuite) TestSearchStatusesFromAccount() {
+	testAccount := suite.testAccounts["local_account_1"]
+	fromAccount := suite.testAccounts["local_account_2"]
+
+	statuses, err := suite.db.SearchForStatuses(context.Background(), testAccount.ID, "hi", fromAccount.ID, "", "", 10, 0)
+	suite.NoError(err)
+	if suite.Len(statuses, 1) {
+		suite.Equal(fromAccount.ID, statuses[0].AccountID)
+	}
+}
+
 func (suite *SearchTestSuite) TestSearchTags() {
 	// Search with full tag string.
 	tags, err := suite.db.SearchForTags(context.Background(), "welcome", "", "", 10, 0)
diff --git a/internal/db/search.go b/internal/db/search.go
index d2ffe4ad5..bdfd3a8e6 100644
--- a/internal/db/search.go
+++ b/internal/db/search.go
@@ -27,8 +27,9 @@ type Search interface {
 	// SearchForAccounts uses the given query text to search for accounts that accountID follows.
 	SearchForAccounts(ctx context.Context, accountID string, query string, maxID string, minID string, limit int, following bool, offset int) ([]*gtsmodel.Account, error)
 
-	// SearchForStatuses uses the given query text to search for statuses created by accountID, or in reply to accountID.
-	SearchForStatuses(ctx context.Context, accountID string, query string, maxID string, minID string, limit int, offset int) ([]*gtsmodel.Status, error)
+	// SearchForStatuses uses the given query text to search for statuses created by requestingAccountID, or in reply to requestingAccountID.
+	// If fromAccountID is used, the results are restricted to statuses created by fromAccountID.
+	SearchForStatuses(ctx context.Context, requestingAccountID string, query string, fromAccountID string, maxID string, minID string, limit int, offset int) ([]*gtsmodel.Status, error)
 
 	// SearchForTags searches for tags that start with the given query text (case insensitive).
 	SearchForTags(ctx context.Context, query string, maxID string, minID string, limit int, offset int) ([]*gtsmodel.Tag, error)
diff --git a/internal/processing/search/get.go b/internal/processing/search/get.go
index e4839a179..d1462cf53 100644
--- a/internal/processing/search/get.go
+++ b/internal/processing/search/get.go
@@ -62,14 +62,15 @@ func (p *Processor) Get(
 	req *apimodel.SearchRequest,
 ) (*apimodel.SearchResult, gtserror.WithCode) {
 	var (
-		maxID     = req.MaxID
-		minID     = req.MinID
-		limit     = req.Limit
-		offset    = req.Offset
-		query     = strings.TrimSpace(req.Query)                      // Trim trailing/leading whitespace.
-		queryType = strings.TrimSpace(strings.ToLower(req.QueryType)) // Trim trailing/leading whitespace; convert to lowercase.
-		resolve   = req.Resolve
-		following = req.Following
+		maxID         = req.MaxID
+		minID         = req.MinID
+		limit         = req.Limit
+		offset        = req.Offset
+		query         = strings.TrimSpace(req.Query)                      // Trim trailing/leading whitespace.
+		queryType     = strings.TrimSpace(strings.ToLower(req.QueryType)) // Trim trailing/leading whitespace; convert to lowercase.
+		resolve       = req.Resolve
+		following     = req.Following
+		fromAccountID = req.AccountID
 
 		// Include instance accounts in the first
 		// parts of this search. This will be
@@ -114,6 +115,7 @@ func (p *Processor) Get(
 			{"queryType", queryType},
 			{"resolve", resolve},
 			{"following", following},
+			{"fromAccountID", fromAccountID},
 		}...).
 		Debugf("beginning search")
 
@@ -309,6 +311,7 @@ func (p *Processor) Get(
 		query,
 		queryType,
 		following,
+		fromAccountID,
 		appendAccount,
 		appendStatus,
 	); err != nil && !errors.Is(err, db.ErrNoEntries) {
@@ -743,6 +746,7 @@ func (p *Processor) byText(
 	query string,
 	queryType string,
 	following bool,
+	fromAccountID string,
 	appendAccount func(*gtsmodel.Account),
 	appendStatus func(*gtsmodel.Status),
 ) error {
@@ -779,6 +783,7 @@ func (p *Processor) byText(
 			limit,
 			offset,
 			query,
+			fromAccountID,
 			appendStatus,
 		); err != nil {
 			return err
@@ -826,12 +831,30 @@ func (p *Processor) statusesByText(
 	limit int,
 	offset int,
 	query string,
+	fromAccountID string,
 	appendStatus func(*gtsmodel.Status),
 ) error {
+	parsed, err := p.parseQuery(ctx, query)
+	if err != nil {
+		return err
+	}
+	query = parsed.query
+	// If the owning account for statuses was not provided as the account_id query parameter,
+	// it may still have been provided as a search operator in the query string.
+	if fromAccountID == "" {
+		fromAccountID = parsed.fromAccountID
+	}
+
 	statuses, err := p.state.DB.SearchForStatuses(
 		ctx,
 		requestingAccountID,
-		query, maxID, minID, limit, offset)
+		query,
+		fromAccountID,
+		maxID,
+		minID,
+		limit,
+		offset,
+	)
 	if err != nil && !errors.Is(err, db.ErrNoEntries) {
 		return gtserror.Newf("error checking database for statuses using text %s: %w", query, err)
 	}
@@ -842,3 +865,60 @@ func (p *Processor) statusesByText(
 
 	return nil
 }
+
+// parsedQuery represents the results of parsing the search operator terms within a query.
+type parsedQuery struct {
+	// query is the original search query text with operator terms removed.
+	query string
+	// fromAccountID is the account from a successfully resolved `from:` operator, if present.
+	fromAccountID string
+}
+
+// parseQuery parses query text and handles any search operator terms present.
+func (p *Processor) parseQuery(ctx context.Context, query string) (parsed parsedQuery, err error) {
+	queryPartSeparator := " "
+	queryParts := strings.Split(query, queryPartSeparator)
+	nonOperatorQueryParts := make([]string, 0, len(queryParts))
+	for _, queryPart := range queryParts {
+		if arg, hasPrefix := strings.CutPrefix(queryPart, "from:"); hasPrefix {
+			parsed.fromAccountID, err = p.parseFromOperatorArg(ctx, arg)
+			if err != nil {
+				return
+			}
+		} else {
+			nonOperatorQueryParts = append(nonOperatorQueryParts, queryPart)
+		}
+	}
+	parsed.query = strings.Join(nonOperatorQueryParts, queryPartSeparator)
+	return
+}
+
+// parseFromOperatorArg attempts to parse the from: operator's argument as an account name,
+// and returns the account ID if possible. Allows specifying an account name with or without a leading @.
+func (p *Processor) parseFromOperatorArg(ctx context.Context, namestring string) (string, error) {
+	if namestring == "" {
+		return "", gtserror.New(
+			"the 'from:' search operator requires an account name, but it wasn't provided",
+		)
+	}
+	if namestring[0] != '@' {
+		namestring = "@" + namestring
+	}
+
+	username, domain, err := util.ExtractNamestringParts(namestring)
+	if err != nil {
+		return "", gtserror.Newf(
+			"the 'from:' search operator couldn't parse its argument as an account name: %w",
+			err,
+		)
+	}
+	account, err := p.state.DB.GetAccountByUsernameDomain(gtscontext.SetBarebones(ctx), username, domain)
+	if err != nil {
+		return "", gtserror.Newf(
+			"the 'from:' search operator couldn't find the requested account name: %w",
+			err,
+		)
+	}
+
+	return account.ID, nil
+}
diff --git a/mkdocs.yml b/mkdocs.yml
index c0132fb2f..a9dbf68cb 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -62,6 +62,7 @@ nav:
   - "User Guide":
       - "user_guide/posts.md"
       - "user_guide/settings.md"
+      - "user_guide/search.md"
       - "user_guide/custom_css.md"
       - "user_guide/password_management.md"
       - "user_guide/rss.md"