Long-Running Coding Work
Trace changes across a repository, implement multi-file features, review code, and check results with your own tests. Evaluate completed tasks and correction time, not just the quality of a single generated patch.
Claude Opus 5.5
Access Anthropic's Claude Opus 5.5 for coding, long-running agents, and document analysis through GPTProto. The model accepts text and images, provides a 1M-token context window and up to 128K output tokens, and uses adaptive thinking. Check the live pricing panel for GPTProto's current rates.
API Usage Examples
curl --request POST "https://gptproto.com/v1/chat/completions" \
--header "Authorization: Bearer $GPTPROTO_API_KEY" \
--header "Content-Type: application/json" \
--data '{
"model": "claude-opus-5-5",
"messages": [
{
"role": "user",
"content": "Hello"
}
]
}'Claude Opus 5.5 pricing
Chat, coding agents & document work. Priced per 1M tokens — input, cached input and output are billed separately. GPTProto is 10% below official rates.
Your usage
Claude · ≈ 148M tokens/mo (48M cached)
OpenRouter
List + 5.5% credit fee
$567.17
per month
Input (non-cached)$135.04
Cache read$10.128
Output$422
Claude
Direct from Claude (list price)
$537.60
per month
Input (non-cached)$128
Cache read$9.6
Output$400
BEST VALUE
GPTProto
10% off official
$483.84
per month
After discount$483.84
Effective$483.84
Monthly cost by source
OpenRouter
$567.17
Claude
$537.60
GPTProto
$483.84
Save $53.76 / month
on GPTProto vs Claude (−10%)
Annual savings ≈ $645.12 · pay as you go
OpenRouter costs include its ~5.5% credit purchase fee. GPTProto applies a per-model discount (10–30% off) and your bonus credits are also spent at discounted rates — savings compound. Estimates assume a 60% cache hit rate.
Related Models
All Models
| Model | Input → Output | ||||
|---|---|---|---|---|---|
| 1M | $3.60 / $18.00 per 1M | $4.50 / $0.18 per 1M | Input: TextInput: ImageInput: Document Output: Text | |
| 1.05M | $0.08 / $0.40 per 1M | $0.10 / $0.008 per 1M | Input: TextInput: ImageInput: Document Output: Text | ||
| 1.05M | $1.60 / $8.00 per 1M | $2.00 / $0.16 per 1M | Input: TextInput: ImageInput: Document Output: Text | ||
| — | $0.03 / — per 1M | — | Input: Text Output: Text | ||
| 500K | $1.20 / $3.60 per 1M | — / $0.30 per 1M | Input: TextInput: Image Output: Text | ||
| — | — | $0.30 / $1.20 per 1M | — / $0.006 per 1M | Input: TextInput: Image Output: Text | |
| 1.05M | $0.79 / $2.38 per 1M | — / $0.04 per 1M | Input: Text Output: Text | ||
| 1.05M | $8.00 / $40.00 per 1M | $10.00 / $0.80 per 1M | Input: TextInput: ImageInput: Document Output: Text | ||
| 1.05M | $0.90 / $4.50 per 1M | $0.60 / $0.09 per 1M | Input: TextInput: ImageInput: VideoInput: DocumentInput: Audio Output: Text | ||
| 1M | $9.00 / $45.00 per 1M | $11.25 / $0.23 per 1M | Input: TextInput: ImageInput: Document Output: Text | ||
| 1M | $1.80 / $5.40 per 1M | $2.25 / $0.23 per 1M | Input: TextInput: ImageInput: VideoInput: DocumentInput: Audio Output: Text | ||
| — | 1.31M | $0.15 / $0.50 per 1M | — / $0.03 per 1M | Input: TextInput: ImageInput: VideoInput: Document Output: Text | |
| — | 1.05M | $0.30 / $1.20 per 1M | — / $0.006 per 1M | Input: TextInput: Image Output: Text | |
| 1.31M | $1.26 / $3.96 per 1M | — / $0.23 per 1M | Input: TextInput: ImageInput: Document Output: Text | ||
| 1.05M | $0.90 / $4.50 per 1M | $0.60 / $0.09 per 1M | Input: TextInput: ImageInput: Document Output: Text | ||
| 500K | $1.20 / $3.60 per 1M | — / $0.30 per 1M | Input: TextInput: Image Output: Text | ||
| 1M | $1.80 / $5.40 per 1M | $2.25 / $0.23 per 1M | Input: TextInput: ImageInput: VideoInput: Document Output: Text | ||
| 1M | $4.50 / $22.50 per 1M | $5.63 / $0.45 per 1M | Input: TextInput: ImageInput: Document Output: Text | ||
| 1.05M | $0.90 / $4.50 per 1M | $0.60 / $0.09 per 1M | Input: TextInput: ImageInput: Document Output: Text | ||
| 1.05M | $2.70 / $13.50 per 1M | $2.70 / $0.27 per 1M | Input: TextInput: ImageInput: Document Output: Text | ||
| 500K | $1.20 / $3.60 per 1M | $0.30 / $0.30 per 1M | Input: TextInput: Image Output: Text | ||
| 1M | $1.80 / $9.00 per 1M | $2.25 / $0.18 per 1M | Input: TextInput: Document Output: Text | ||
| 1.05M | $0.48 / $0.96 per 1M | $0.10 / $0.10 per 1M | Input: TextInput: ImageInput: Document Output: Text | ||
| 1.05M | $1.26 / $3.96 per 1M | $0.23 / $0.23 per 1M | Input: TextInput: ImageInput: Document Output: Text | ||
| 1M | $9.00 / $45.00 per 1M | $11.25 / $0.90 per 1M | Input: TextInput: Document Output: Text | ||
| 1M | $0.36 / $1.44 per 1M | $0.07 / $0.07 per 1M | Input: TextInput: Document Output: Text | ||
| 1M | $4.50 / $22.50 per 1M | $5.63 / $0.45 per 1M | Input: TextInput: Document Output: Text | ||
| 1M | $4.50 / $22.50 per 1M | $5.63 / $0.45 per 1M | Input: TextInput: Document Output: Text | ||
| — | 1.05M | $0.30 / $1.20 per 1M | — / $0.006 per 1M | Input: Text Output: Text | |
| 262K | $0.85 / $3.60 per 1M | $0.14 / $0.14 per 1M | Input: TextInput: Document Output: Text | ||
| 205K | $0.24 / $0.96 per 1M | $0.30 / $0.02 per 1M | Input: TextInput: Document Output: Text | ||
| 262K | $0.54 / $2.70 per 1M | $0.09 / $0.09 per 1M | Input: TextInput: Document Output: Text | ||
| 262K | $0.10 / $0.97 per 1M | — | Input: TextInput: Image Output: Text | ||
| 262K | $0.10 / $0.97 per 1M | — | Input: TextInput: Image Output: Text | ||
| 262K | $0.02 / $0.18 per 1M | — | Input: TextInput: Image Output: Text |
Claude Opus 5.5 API for Coding and Long-Running Agents
Run Anthropic's Opus 5.5 with one GPTProto key for complex coding, multi-step agent work, and professional analysis. It supports text and image input, a 1M-token context window, and 128K maximum output. Compare its live GPTProto price with Anthropic's published rate before deploying.
1M Context and 128K Output
Provide large codebases, documents, and agent history as context and request substantial text output. These are model limits, not a promise that every long input will be equally relevant to the answer.
Adaptive Thinking and Tool Use
Thinking is always on; its default effort is medium. Build tool-driven workflows that inspect outputs and continue after failures. Verify that your GPTProto integration passes through any model-specific effort, tool, and thinking fields you need.
Image Understanding and Clear Reports
Supply supported image input for screenshot, chart, and diagram analysis, then request a text response. For PDF uploads or specialized computer-use tools, verify the GPTProto endpoint's supported request format before promising them in your application.
What Is the Claude Opus 5.5 API?
Claude Opus 5.5 is Anthropic's model for long-running agentic coding and knowledge work, released on September 22, 2026. The API accepts text and images and returns text. Anthropic lists a 1,000,000-token context window, a standard maximum output of 128,000 tokens, and adaptive thinking that cannot be disabled. The default effort setting is medium; an application can tune effort for the depth of work it needs. The official Claude API model ID is claude-opus-5-5. Confirm the exact GPTProto model string in this page's API Usage tab before sending production traffic.
| Specification | Claude Opus 5.5 |
|---|---|
| Provider | Anthropic |
| Released | September 22, 2026 |
| Input → output | Text and images → text |
| Context window | 1M tokens |
| Maximum standard output | 128K tokens |
| Thinking | Adaptive, always on; medium effort by default |
| Official Claude API model ID | claude-opus-5-5 |
| Anthropic standard API price | $4 input / $20 output per 1M tokens; not the verified GPTProto rate |
The practical fit is work that needs repeated inspection and revision: debugging across files, migrations, code review, multi-tool agents, and document-heavy analysis. For routine extraction or brief responses, compare a less expensive model on the same tasks. A large context window makes it possible to send more material; it does not replace retrieval, selective context, or checks on the final answer.
Claude Opus 5.5 vs Opus 5 and Fable 5.1
| Decision factor | Opus 5.5 | Opus 5 | Fable 5.1 |
|---|---|---|---|
| Official input / output price per 1M tokens | $4 / $20 | $5 / $25 | $10 / $50 |
| Context / standard maximum output | 1M / 128K | 1M / 128K | 1M / 128K |
| Thinking | Always-on adaptive | Adaptive | Always-on adaptive |
| Default effort | Medium | Check model settings | High |
| Starting point | Agentic coding and everyday complex work | Existing, validated Opus 5 applications | Demanding reasoning after Opus 5.5 falls short in your evaluations |
The rates above are Anthropic's standard list prices, not GPTProto prices. Opus 5.5 has 20% lower official input and output token rates than Opus 5, but cost per finished task also depends on tool calls, cache hits, retries, and output length. Anthropic says Opus 5.5 reaches Fable 5.1's level on most work; that is a vendor claim, not a guarantee for your workload. Test each model with the same prompts, tools, and acceptance criteria. For current platform charges, use the fixed pricing panel above.
Migrating from Claude Opus 5: Four Checks That Matter
Replacing claude-opus-5 with claude-opus-5-5 is the first step. If your agent sends Anthropic-specific fields through GPTProto, check whether the selected endpoint forwards them and run a small canary before switching traffic:
Remove manual thinking settings. Opus 5.5 rejects both
thinking.type: "disabled"and the olderthinking.type: "enabled"with a token budget. On the native Claude Messages API, tune depth withoutput_config.effortinstead. Confirm how GPTProto exposes this control.Stop forcing a particular tool. Anthropic documents errors for
tool_choicevaluesanyandtoolon Opus 5.5. Useautoand validate your tool schema and output handling in the API format you actually call.Preserve thinking blocks across turns. Thinking blocks are associated with the model and conversation. A fallback model may ignore prior Opus 5.5 thinking blocks; editing earlier turns or tool definitions can also break a conversation. Test a full multi-turn tool loop, not only a single request.
Recheck computer use integrations. On Anthropic's Claude API and Google Cloud, the older
computer_20251124tool is not supported by Opus 5.5. If you use computer control, confirm both Anthropic's current toolset and GPTProto's exposure before migrating.
These checks address request compatibility. Also measure completion rate, latency, total tokens, and cost per accepted result on a representative set of coding or agent tasks. Anthropic's migration guide documents the native API changes; GPTProto support for individual fields must be verified separately.
FAQ
What is the Claude Opus 5.5 API pricing on GPTProto?
Use the live GPTProto pricing panel on this page for input, output, and any cache-related charges. Anthropic's published standard rate is $4 per million input tokens and $20 per million output tokens; those are official rates, not a confirmed GPTProto quote. A lower input/output rate does not automatically mean lower cost for every agent run.
How do I get a Claude Opus 5.5 API key and test the model?
Create a GPTProto key in your account, select Claude Opus 5.5, and use this page's Try this model action or the API Usage tab for the live model string and request format. Keep the key on your server. One GPTProto account can be used to compare models without maintaining a separate key for each provider.
Is the Claude Opus 5.5 API open source?
No. Anthropic provides hosted access to this proprietary model; an API key does not provide model weights or a self-hosting license.
Does Claude Opus 5.5 accept images or generate images?
Anthropic lists text and image input with text output. It can analyze supported images, but this API does not generate image files. Verify the GPTProto request format for image input and any document upload flow you plan to use.
What changes when migrating from the Claude Opus 5 API?
The model ID changes, and always-on thinking can reject older thinking settings. Forced tool choices can also fail; preserved thinking and some computer-use declarations require special handling. Test your actual GPTProto endpoint for these fields before replacing an Opus 5 deployment.
Claude Opus 5.5 vs Fable 5.1: which is better for agents?
Begin with Opus 5.5 for complex daily work. Anthropic positions Fable 5.1 for demanding reasoning or long-horizon tasks when Opus 5.5 at higher effort still falls short. Their official token rates are $4/$20 and $10/$50 per million input/output tokens respectively; evaluate total cost per successful task, not only the token rate.
Can I use Claude Opus 5.5 for long-running coding agents?
Yes, the model is intended for agentic coding and multi-step work. Your application still needs to manage tools, state, retries, permissions, and evaluation. A model API call alone does not run an autonomous agent or guarantee completion of a long task.
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