Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
One change · api

token-counting changed

build-with-claude/token-counting

Nearest release: v2.1.280, published under an hour before this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.

Recorded here
Lines+45added
Lines−45removed
From line 52 where the diff opens
First seen 14 Aug 2026 this site's first read of the page
Recorded edits10to this page, all time

The whole hunk

from line 52, old and new numbered
/
lines
from line 52
5252 -H "content-type: application/json" \
5353 -H "anthropic-version: 2023-06-01" \
5454 -d '{
55 "model": "claude-opus-5",
55 "model": "claude-opus-5-5",
5656 "system": "You are a scientist",
5757 "messages": [{
5858 "role": "user",
from line 63
6363 
6464 ```bash CLI
6565 ant messages count-tokens \
66 --model claude-opus-5 \
66 --model claude-opus-5-5 \
6767 --system "You are a scientist" \
6868 --message '{role: user, content: "Hello, Claude"}'
6969 ```
from line 72
7272 client = anthropic.Anthropic()
7373 
7474 response = client.messages.count_tokens(
75 model="claude-opus-5",
75 model="claude-opus-5-5",
7676 system="You are a scientist",
7777 messages=[{"role": "user", "content": "Hello, Claude"}],
7878 )
from line 84
8484 const client = new Anthropic();
8585 
8686 const response = await client.messages.countTokens({
87 model: "claude-opus-5",
87 model: "claude-opus-5-5",
8888 system: "You are a scientist",
8989 messages: [
9090 {
from line 107
107107 
108108 var parameters = new MessageCountTokensParams
109109 {
110 Model = Model.ClaudeOpus5,
110 Model = Model.ClaudeOpus5_5,
111111 System = "You are a scientist",
112112 Messages = [new() { Role = Role.User, Content = "Hello, Claude" }]
113113 };
from line 120
120120 client := anthropic.NewClient()
121121 
122122 response, err := client.Messages.CountTokens(context.TODO(), anthropic.MessageCountTokensParams{
123 Model: anthropic.ModelClaudeOpus5,
123 Model: anthropic.ModelClaudeOpus5_5,
124124 System: anthropic.MessageCountTokensParamsSystemUnion{
125125 OfString: anthropic.String("You are a scientist"),
126126 },
from line 146
146146 AnthropicClient client = AnthropicOkHttpClient.fromEnv();
147147 
148148 MessageCountTokensParams params = MessageCountTokensParams.builder()
149 .model(Model.CLAUDE_OPUS_5)
149 .model(Model.CLAUDE_OPUS_5_5)
150150 .system("You are a scientist")
151151 .addUserMessage("Hello, Claude")
152152 .build();
from line 164
164164 messages: [
165165 ['role' => 'user', 'content' => 'Hello, Claude']
166166 ],
167 model: 'claude-opus-5',
167 model: 'claude-opus-5-5',
168168 system: 'You are a scientist',
169169 );
170170 
from line 175
175175 client = Anthropic::Client.new
176176 
177177 response = client.messages.count_tokens(
178 model: "claude-opus-5",
178 model: "claude-opus-5-5",
179179 system: "You are a scientist",
180180 messages: [
181181 { role: "user", content: "Hello, Claude" }
from line 203
203203 -H "content-type: application/json" \
204204 -H "anthropic-version: 2023-06-01" \
205205 -d '{
206 "model": "claude-opus-5",
206 "model": "claude-opus-5-5",
207207 "tools": [
208208 {
209209 "name": "get_weather",
from line 231
231231 
232232 ```bash CLI
233233 ant messages count-tokens <<'YAML'
234 model: claude-opus-5
234 model: claude-opus-5-5
235235 tools:
236236 - name: get_weather
237237 description: Get the current weather in a given location
from line 253
253253 client = anthropic.Anthropic()
254254 
255255 response = client.messages.count_tokens(
256 model="claude-opus-5",
256 model="claude-opus-5-5",
257257 tools=[
258258 {
259259 "name": "get_weather",
from line 280
280280 const client = new Anthropic();
281281 
282282 const response = await client.messages.countTokens({
283 model: "claude-opus-5",
283 model: "claude-opus-5-5",
284284 tools: [
285285 {
286286 name: "get_weather",
from line 315
315315 
316316 var parameters = new MessageCountTokensParams
317317 {
318 Model = Model.ClaudeOpus5,
318 Model = Model.ClaudeOpus5_5,
319319 Tools =
320320 [
321321 new MessageCountTokensTool(new Tool()
from line 343
343343 client := anthropic.NewClient()
344344 
345345 response, err := client.Messages.CountTokens(context.TODO(), anthropic.MessageCountTokensParams{
346 Model: anthropic.ModelClaudeOpus5,
346 Model: anthropic.ModelClaudeOpus5_5,
347347 Tools: []anthropic.MessageCountTokensToolUnionParam{
348348 {OfTool: &anthropic.ToolParam{
349349 Name: "get_weather",
from line 395
395395 .build();
396396 
397397 MessageCountTokensParams params = MessageCountTokensParams.builder()
398 .model(Model.CLAUDE_OPUS_5)
398 .model(Model.CLAUDE_OPUS_5_5)
399399 .addTool(
400400 Tool.builder()
401401 .name("get_weather")
from line 417
417417 messages: [
418418 ['role' => 'user', 'content' => "What's the weather like in San Francisco?"]
419419 ],
420 model: 'claude-opus-5',
420 model: 'claude-opus-5-5',
421421 tools: [
422422 [
423423 'name' => 'get_weather',
from line 443
443443 client = Anthropic::Client.new
444444 
445445 response = client.messages.count_tokens(
446 model: "claude-opus-5",
446 model: "claude-opus-5-5",
447447 tools: [
448448 {
449449 name: "get_weather",
from line 489
489489 -H "content-type: application/json" \
490490 -d @- <<EOF
491491 {
492 "model": "claude-opus-5",
492 "model": "claude-opus-5-5",
493493 "messages": [
494494 {"role": "user", "content": [
495495 {"type": "image", "source": {
from line 509
509509 curl -s "$IMAGE_URL" -o ./vision-example.jpg
510510 
511511 ant messages count-tokens <<'YAML'
512 model: claude-opus-5
512 model: claude-opus-5-5
513513 messages:
514514 - role: user
515515 content:
from line 534
534534 client = anthropic.Anthropic()
535535 
536536 response = client.messages.count_tokens(
537 model="claude-opus-5",
537 model="claude-opus-5-5",
538538 messages=[
539539 {
540540 "role": "user",
from line 564
564564 const imageData = Buffer.from(imageArrayBuffer).toString("base64");
565565 
566566 const response = await anthropic.messages.countTokens({
567 model: "claude-opus-5",
567 model: "claude-opus-5-5",
568568 messages: [
569569 {
570570 role: "user",
from line 606
606606 
607607 var parameters = new MessageCountTokensParams
608608 {
609 Model = Model.ClaudeOpus5,
609 Model = Model.ClaudeOpus5_5,
610610 Messages =
611611 [
612612 new()
from line 655
655655 client := anthropic.NewClient()
656656 
657657 response, err := client.Messages.CountTokens(context.TODO(), anthropic.MessageCountTokensParams{
658 Model: anthropic.ModelClaudeOpus5,
658 Model: anthropic.ModelClaudeOpus5_5,
659659 Messages: []anthropic.MessageParam{
660660 anthropic.NewUserMessage(
661661 anthropic.NewImageBlockBase64("image/jpeg", imageData),
from line 705
705705 );
706706 
707707 MessageCountTokensParams params = MessageCountTokensParams.builder()
708 .model(Model.CLAUDE_OPUS_5)
708 .model(Model.CLAUDE_OPUS_5_5)
709709 .addUserMessageOfBlockParams(List.of(imageBlock, textBlock))
710710 .build();
711711 
from line 737
737737 ]
738738 ]
739739 ],
740 model: 'claude-opus-5',
740 model: 'claude-opus-5-5',
741741 );
742742 print_r($response);
743743 ```
from line 755
755755 client = Anthropic::Client.new
756756 
757757 response = client.messages.count_tokens(
758 model: "claude-opus-5",
758 model: "claude-opus-5-5",
759759 messages: [
760760 {
761761 role: "user",
from line 799
799799 -H "content-type: application/json" \
800800 -H "anthropic-version: 2023-06-01" \
801801 -d '{
802 "model": "claude-opus-5",
802 "model": "claude-opus-5-5",
803803 "thinking": {
804804 "type": "adaptive"
805805 },
from line 832
832832 
833833 ```bash CLI
834834 ant messages count-tokens <<'YAML'
835 model: claude-opus-5
835 model: claude-opus-5-5
836836 thinking:
837837 type: adaptive
838838 messages:
from line 856
856856 client = anthropic.Anthropic()
857857 
858858 response = client.messages.count_tokens(
859 model="claude-opus-5",
859 model="claude-opus-5-5",
860860 thinking={"type": "adaptive"},
861861 messages=[
862862 {
from line 888
888888 const client = new Anthropic();
889889 
890890 const response = await client.messages.countTokens({
891 model: "claude-opus-5",
891 model: "claude-opus-5-5",
892892 thinking: { type: "adaptive" },
893893 messages: [
894894 {
from line 932
932932 
933933 var parameters = new MessageCountTokensParams
934934 {
935 Model = Model.ClaudeOpus5,
935 Model = Model.ClaudeOpus5_5,
936936 Thinking = new ThinkingConfigAdaptive(),
937937 Messages =
938938 [
from line 979
979979 )
980980 
981981 response, err := client.Messages.CountTokens(context.TODO(), anthropic.MessageCountTokensParams{
982 Model: anthropic.ModelClaudeOpus5,
982 Model: anthropic.ModelClaudeOpus5_5,
983983 Thinking: anthropic.ThinkingConfigParamUnion{
984984 OfAdaptive: &anthropic.ThinkingConfigAdaptiveParam{},
985985 },
from line 1024
10241024 );
10251025 
10261026 MessageCountTokensParams params = MessageCountTokensParams.builder()
1027 .model(Model.CLAUDE_OPUS_5)
1027 .model(Model.CLAUDE_OPUS_5_5)
10281028 .thinking(ThinkingConfigAdaptive.builder().build())
10291029 .addUserMessage("Are there an infinite number of prime numbers such that n mod 4 == 3?")
10301030 .addAssistantMessageOfBlockParams(assistantBlocks)
from line 1063
10631063 'content' => 'Can you write a formal proof?'
10641064 ]
10651065 ],
1066 model: 'claude-opus-5',
1066 model: 'claude-opus-5-5',
10671067 thinking: ['type' => 'adaptive'],
10681068 );
10691069 
from line 1074
10741074 client = Anthropic::Client.new
10751075 
10761076 response = client.messages.count_tokens(
1077 model: "claude-opus-5",
1077 model: "claude-opus-5-5",
10781078 thinking: {
10791079 type: "adaptive"
10801080 },
from line 1126
11261126 -H "anthropic-version: 2023-06-01" \
11271127 -d @- <<EOF
11281128 {
1129 "model": "claude-opus-5",
1129 "model": "claude-opus-5-5",
11301130 "messages": [{
11311131 "role": "user",
11321132 "content": [
from line 1150
11501150 
11511151 ```bash CLI
11521152 ant messages count-tokens <<'YAML'
1153 model: claude-opus-5
1153 model: claude-opus-5-5
11541154 messages:
11551155 - role: user
11561156 content:
from line 1174
11741174 pdf_base64 = base64.standard_b64encode(pdf_file.read()).decode("utf-8")
11751175 
11761176 response = client.messages.count_tokens(
1177 model="claude-opus-5",
1177 model="claude-opus-5-5",
11781178 messages=[
11791179 {
11801180 "role": "user",
from line 1204
12041204 const pdfBase64 = await readFile("/path/to/document.pdf", { encoding: "base64" });
12051205 
12061206 const response = await client.messages.countTokens({
1207 model: "claude-opus-5",
1207 model: "claude-opus-5-5",
12081208 messages: [
12091209 {
12101210 role: "user",
from line 1244
12441244 
12451245 var parameters = new MessageCountTokensParams
12461246 {
1247 Model = Model.ClaudeOpus5,
1247 Model = Model.ClaudeOpus5_5,
12481248 Messages =
12491249 [
12501250 new()
from line 1278
12781278 pdfBase64 := base64.StdEncoding.EncodeToString(pdfBytes)
12791279 
12801280 response, err := client.Messages.CountTokens(context.TODO(), anthropic.MessageCountTokensParams{
1281 Model: anthropic.ModelClaudeOpus5,
1281 Model: anthropic.ModelClaudeOpus5_5,
12821282 Messages: []anthropic.MessageParam{
12831283 anthropic.NewUserMessage(
12841284 anthropic.NewDocumentBlock(anthropic.Base64PDFSourceParam{
from line 1318
13181318 );
13191319 
13201320 MessageCountTokensParams params = MessageCountTokensParams.builder()
1321 .model(Model.CLAUDE_OPUS_5)
1321 .model(Model.CLAUDE_OPUS_5_5)
13221322 .addUserMessageOfBlockParams(List.of(documentBlock, textBlock))
13231323 .build();
13241324 
from line 1351
13511351 ]
13521352 ]
13531353 ],
1354 model: 'claude-opus-5',
1354 model: 'claude-opus-5-5',
13551355 );
13561356 
13571357 echo json_encode($response);
from line 1365
13651365 pdf_base64 = Base64.strict_encode64(File.binread("/path/to/document.pdf"))
13661366 
13671367 response = client.messages.count_tokens(
1368 model: "claude-opus-5",
1368 model: "claude-opus-5-5",
13691369 messages: [
13701370 {
13711371 role: "user",