Step 3.5 Flash is StepFun’s sparse mixture-of-experts text model for reasoning and agent-oriented work. The published specification has 196.81 billion total parameters, including its prediction head, and activates about 11B parameters per token. It processes written instructions and conversation to generate text, code and proposed tool interactions.
Its 45-layer backbone combines sliding-window and full attention in a three-to-one ratio and supports a 256K context. Each expert layer has 288 routed experts plus a shared expert, with eight routed experts selected per token. A multi-token-prediction head is part of the producer’s efficiency design. These architectural choices describe the model; a particular application’s speed also depends on its serving setup and workload.
The central task areas are reasoning, coding and longer agent workflows. For a software assignment, provide the expected behavior, the relevant source and an actual failure or requested change. Ask for the proposed artifact and the checks needed to assess it. In a connected application, return the results of commands and checks before the model chooses its next step.
For long-context analysis, define the question and the sections of the material that matter. A useful report identifies its conclusion, the evidence supporting it and any missing observation. Keep the current objective and earlier confirmed findings available over follow-up turns so that the model can continue from the task’s state rather than reconstruct it from an incomplete prompt.
StepFun publishes integration and local-deployment recipes for coding and research applications. Tool execution belongs to the surrounding workflow: the model supplies the proposed action, and the application runs it and returns the outcome. Distinct converted or quantized artifacts have their own deployment conditions; the general model name does not choose one of them.
The producer’s known issues are concrete. The model can use long generation trajectories, and stability can decrease in specialized domains or extended multi-turn conversations. Reported symptoms include repetitive reasoning, mixed-language output and inconsistencies about time or identity. Specify the response language and the current task clearly, preserve the relevant observations and review the final artifact against the stated objective. Keep this text edition distinct from Step 3.7 Flash’s added vision encoder and image input.
", "aboutText": "Step 3.5 Flash is StepFun’s sparse mixture-of-experts text model for reasoning and agent-oriented work. The published specification has 196.81 billion total parameters, including its prediction head, and activates about 11B parameters per token. It processes written instructions and conversation to generate text, code and proposed tool interactions.\n\nIts 45-layer backbone combines sliding-window and full attention in a three-to-one ratio and supports a 256K context. Each expert layer has 288 routed experts plus a shared expert, with eight routed experts selected per token. A multi-token-prediction head is part of the producer’s efficiency design. These architectural choices describe the model; a particular application’s speed also depends on its serving setup and workload.\n\nThe central task areas are reasoning, coding and longer agent workflows. For a software assignment, provide the expected behavior, the relevant source and an actual failure or requested change. Ask for the proposed artifact and the checks needed to assess it. In a connected application, return the results of commands and checks before the model chooses its next step.\n\nFor long-context analysis, define the question and the sections of the material that matter. A useful report identifies its conclusion, the evidence supporting it and any missing observation. Keep the current objective and earlier confirmed findings available over follow-up turns so that the model can continue from the task’s state rather than reconstruct it from an incomplete prompt.\n\nStepFun publishes integration and local-deployment recipes for coding and research applications. Tool execution belongs to the surrounding workflow: the model supplies the proposed action, and the application runs it and returns the outcome. Distinct converted or quantized artifacts have their own deployment conditions; the general model name does not choose one of them.\n\nThe producer’s known issues are concrete. The model can use long generation trajectories, and stability can decrease in specialized domains or extended multi-turn conversations. Reported symptoms include repetitive reasoning, mixed-language output and inconsistencies about time or identity. Specify the response language and the current task clearly, preserve the relevant observations and review the final artifact against the stated objective. Keep this text edition distinct from Step 3.7 Flash’s added vision encoder and image input.", "editorialOverlay": { "copy_fields": { "practical_html": "Technical example in English
Repair a stale accumulator default\n\nReview this Python function: def collect(value, items=[]): items.append(value); return items. Separate calls unexpectedly share earlier values. Propose a correction that preserves caller-supplied list mutation but creates a fresh list when the argument is omitted. Include tests for two omitted-argument calls and a call with an explicit list. Explain the changed default behavior.A corrected function and tests distinguishing fresh defaults from deliberate mutation of a supplied list.Omitted calls do not share state, while an explicit caller list retains the documented mutation behavior.stepfun/step-3.5-flashStepFun’s Step 3.5 Flash is a sparse text model for reasoning, code and agent workflows. It activates about 11B parameters from its 196B-class model, combines sliding and full attention, and supports a 256K context.
This description covers the model’s capabilities. Available in Ailoot inputs, outputs and options are listed for the selected method below.
Step 3.5 Flash is StepFun’s sparse mixture-of-experts text model for reasoning and agent-oriented work. The published specification has 196.81 billion total parameters, including its prediction head, and activates about 11B parameters per token. It processes written instructions and conversation to generate text, code and proposed tool interactions.
Its 45-layer backbone combines sliding-window and full attention in a three-to-one ratio and supports a 256K context. Each expert layer has 288 routed experts plus a shared expert, with eight routed experts selected per token. A multi-token-prediction head is part of the producer’s efficiency design. These architectural choices describe the model; a particular application’s speed also depends on its serving setup and workload.
The central task areas are reasoning, coding and longer agent workflows. For a software assignment, provide the expected behavior, the relevant source and an actual failure or requested change. Ask for the proposed artifact and the checks needed to assess it. In a connected application, return the results of commands and checks before the model chooses its next step.
For long-context analysis, define the question and the sections of the material that matter. A useful report identifies its conclusion, the evidence supporting it and any missing observation. Keep the current objective and earlier confirmed findings available over follow-up turns so that the model can continue from the task’s state rather than reconstruct it from an incomplete prompt.
StepFun publishes integration and local-deployment recipes for coding and research applications. Tool execution belongs to the surrounding workflow: the model supplies the proposed action, and the application runs it and returns the outcome. Distinct converted or quantized artifacts have their own deployment conditions; the general model name does not choose one of them.
The producer’s known issues are concrete. The model can use long generation trajectories, and stability can decrease in specialized domains or extended multi-turn conversations. Reported symptoms include repetitive reasoning, mixed-language output and inconsistencies about time or identity. Specify the response language and the current task clearly, preserve the relevant observations and review the final artifact against the stated objective. Keep this text edition distinct from Step 3.7 Flash’s added vision encoder and image input.
POST /v1/chat/completionstexttext| Field | Type | Requirement | Values & limits | Default |
|---|---|---|---|---|
Fieldmodel | Typestring | RequirementRequired | Values & limits stepfun/step-3.5-flash | Default— |
Fieldmessages | Typemessage[] | RequirementRequired | Values & limits Minimum items: 1 | Default— |
Fieldmessages[].role | Typestring | RequirementRequired | Values & limits Examples: system, user, assistant, tool, function Conditions: These roles are explicitly represented by Source compatibility types; the exact model role set remains model-specific. Model-specific | Default— |
Fieldmessages[].content | Typestring|content_part[]|null | RequirementOptional | Values & limits | Default— |
Fieldmessages[].tool_calls | Typetool_call[] | RequirementOptional | Values & limits | Default— |
Fieldmessages[].tool_call_id | Typestring | RequirementOptional | Values & limits Applies when: role=tool; use actual returned ID | Default— |
Fieldmessages[].name | Typestring | RequirementOptional | Values & limits | Default— |
Fieldmessages[].reasoning_content | Typestring | RequirementOptional | Values & limits Applies when: Round-trip actual returned reasoning where this model uses it | Default— |
Fieldmessages[].reasoning_details | Typeobject|array | RequirementOptional | Values & limits Model-specific | Default— |
Fieldmax_tokens | Typeinteger | RequirementOptional | Values & limits Minimum: 1 Model-specific | Default— |
Fieldmax_completion_tokens | Typeinteger | RequirementOptional | Values & limits Minimum: 1 Model-specific | Default— |
Fieldstream | Typeboolean | RequirementOptional | Values & limits | Defaultfalse |
Fieldstream_options.include_usage | Typeboolean | RequirementOptional | Values & limits Model-specific | Default— |
Fieldtemperature | Typenumber | RequirementOptional | Values & limits Model-specific | Default— |
Fieldtop_p | Typenumber | RequirementOptional | Values & limits Model-specific | Default— |
Fieldstop | Typestring|string[] | RequirementOptional | Values & limits Model-specific | Default— |
Fieldtools | Typefunction_tool[] | RequirementOptional | Values & limits Model-specific | Default— |
Fieldtools[].type | Typestring | RequirementOptional | Values & limits function Model-specific | Default— |
Fieldtools[].function.name | Typestring | RequirementRequired | Values & limits Applies when: function tool supplied | Default— |
Fieldtools[].function.description | Typestring | RequirementOptional | Values & limits | Default— |
Fieldtools[].function.parameters | TypeJSON_schema | RequirementOptional | Values & limits | Default— |
Fieldtool_choice | Typestring|object | RequirementOptional | Values & limits Model-specific | Default— |
Fieldparallel_tool_calls | Typeboolean | RequirementOptional | Values & limits Model-specific | Default— |
Fieldresponse_format | Typeobject | RequirementOptional | Values & limits Model-specific | Default— |
Fieldreasoning_effort | Typestring | RequirementOptional | Values & limits Model-specific | Default— |
Fieldreasoning | Typeobject | RequirementOptional | Values & limits Model-specific | Default— |
Fieldservice_tier | Typestring | RequirementOptional | Values & limits Model-specific | Default— |
Fieldinstructions | Typestring | RequirementOptional | Values & limits Compatibility field | Default— |
Fieldfunctions | Typefunction[] | RequirementOptional | Values & limits Model-specific | Default— |
Fieldfunction_call | Typestring|object | RequirementOptional | Values & limits Model-specific | Default— |
Fieldprompt_cache_options | Typeobject | RequirementOptional | Values & limits Model-specific | Default— |
Fieldmodalities | Typestring[] | RequirementOptional | Values & limits text | Default— |
Fieldprovider | Typeobject | RequirementOptional | Values & limits Conditions: provider.options is rejected on this Ultra text route | Default— |
Fieldcache_control.ttl | Typestring | RequirementOptional | Values & limits Conditions: 1h is rejected in actual prompt-cache locations | Default— |
Text · UTF8 text
messages[].content
| Parameter | Contract |
|---|---|
Parametercontent_type | Contractapplication/json |
Parameterrequired | Contractmodel, messages |
Parametermaterial_types | Contracttext |
Parametermessages | Contractmessage array with role/content shape |
Parameterfile_material | Contractactual UTF-8 document inserted as literal text; no file ID inferred |
Parameteroptional_controls | Contractstream, temperature, top_p, stop, max_tokens, max_completion_tokens, reasoning, response_format, tools, tool_choice |
Parametercontrol_scope | Contractmodel-specific; user function tools differ from hosted tools |
Parameteroutput_modalities | Contracttext |
Parameterhosted_operations | Contractfalse |
Parametermultimodal_input_binding | Contractnull |
Lifecycle: synchronous_or_streamed
Send exact model ID with messages.
Context length is not an output cap.
A text file may supply literal text; image/audio/file-object inputs need exact binding.
Tariff references do not add request options. Supported parameters are listed for the selected method.
Match each charge to the conditions shown. Use one rate for each set of alternative configurations.
| Configuration | Rate schedule | Context tokens, more than | Context tokens, up to and including | Charge |
|---|---|---|---|---|
| ConfigurationBase token rates | Rate scheduleBase rate | Context tokens, more than— | Context tokens, up to and includingNo upper bound | Charge Input · Input tokens $0.00022 / 1K tokens Output · Output tokens $0.00066 / 1K tokens Input · Cache read $0 / 1K tokens Input · Cache write $0 / 1K tokens Input · Cache write, 1 hour — / 1K tokens |
| ConfigurationRequest-length tier 1 | Rate schedule— | Context tokens, more than0 | Context tokens, up to and includingNo upper bound | Charge Input · Input tokens $0.00022 / 1K tokens Output · Output tokens $0.00066 / 1K tokens Input · Cache read $0 / 1K tokens Input · Cache write $0 / 1K tokens Input · Cache write, 1 hour — / 1K tokens |
Ailoot reserves an estimated amount before a request. After the result, it settles the final charge from measured usage. Streaming settlement uses the final usage record. How reservation and settlement work →
set -eu\n: "${AILOOT_API_KEY:?Set your Ailoot API key}"\npython3 - <<'PY_REQUEST'\nimport json,os\nfrom pathlib import Path\np=json.loads('{"model": "stepfun/step-3.5-flash", "messages": [{"role": "user", "content": "Explain the difference between an observation and a hypothesis in three sentences."}]}')\n\nPath("request.json").write_text(json.dumps(p,ensure_ascii=False))\nPY_REQUEST\ncurl --fail-with-body --silent --show-error https://api.ailoot.ai/v1/chat/completions \\\n -H "Authorization: Bearer $AILOOT_API_KEY" -H 'Content-Type: application/json' \\\n --data-binary @request.json -D response-headers.txt -o result.json\npython3 - <<'PY_RESULT'\nimport json\nfrom pathlib import Path\nr=json.loads(Path("result.json").read_text())\nfor x in r.get("choices",[]):\n if x.get("message",{}).get("content"): print(x["message"]["content"])\nPY_RESULT\nfrom openai import OpenAI\nimport os\n\nif not os.environ.get("AILOOT_API_KEY", "").strip(): raise SystemExit("Set AILOOT_API_KEY before making a request")\nclient=OpenAI(base_url="https://api.ailoot.ai/v1",api_key=os.environ["AILOOT_API_KEY"],max_retries=0)\nresult=client.chat.completions.create(model='stepfun/step-3.5-flash',messages=[{"role":"user","content":"Explain observations and hypotheses in three sentences."}])\nimport base64, json\nfrom pathlib import Path\n\ndef save_result(data, stem="result"):\n # Keep every field, including usage, IDs, reasoning and tool requests.\n Path(stem + ".json").write_text(json.dumps(data, ensure_ascii=False, indent=2), encoding="utf-8")\n print(json.dumps(data, ensure_ascii=False, indent=2))\n def save_blob(encoded, suffix, label):\n raw = base64.b64decode(encoded, altchars=b"-_", validate=True)\n ext = "png" if raw.startswith(b"\\x89PNG\\r\\n\\x1a\\n") else "jpg" if raw.startswith(b"\\xff\\xd8") else "webp" if raw[:4] == b"RIFF" and raw[8:12] == b"WEBP" else suffix\n file = Path(stem + "-" + label + "." + ext)\n file.write_bytes(raw)\n print("Saved", file)\n for index, block in enumerate(data.get("content") or []):\n print("Content", index, json.dumps(block, ensure_ascii=False))\n for choice in data.get("choices") or []:\n print("Choice", choice.get("index"), json.dumps(choice.get("message", choice.get("delta", {})), ensure_ascii=False))\n for index, item in enumerate(data.get("output") or []):\n print("Output", index, json.dumps(item, ensure_ascii=False))\n if item.get("type") == "image_generation_call" and item.get("result"):\n save_blob(item["result"], item.get("output_format") or "bin", "output-" + str(index))\n for ci, candidate in enumerate(data.get("candidates") or []):\n for pi, part in enumerate((candidate.get("content") or {}).get("parts") or []):\n print("Candidate/part", ci, pi, json.dumps(part, ensure_ascii=False))\n blob = part.get("inlineData") or part.get("inline_data")\n if blob and blob.get("data"):\n mime = blob.get("mimeType") or blob.get("mime_type")\n suffix = {"image/png":"png", "image/jpeg":"jpg", "image/webp":"webp", "audio/wav":"wav", "audio/mpeg":"mp3", "video/mp4":"mp4"}.get(mime, "bin")\n save_blob(blob["data"], suffix, "candidate-" + str(ci) + "-part-" + str(pi))\n\nsave_result(result.to_dict(mode="json"))\nfrom openai import OpenAI\nimport os\nfrom pathlib import Path\n\nif not os.environ.get("AILOOT_API_KEY", "").strip(): raise SystemExit("Set AILOOT_API_KEY before making a request")\nclient=OpenAI(base_url="https://api.ailoot.ai/v1",api_key=os.environ["AILOOT_API_KEY"],max_retries=0)\nimport base64, json\nfrom pathlib import Path\n\ndef save_result(data, stem="result"):\n # Keep every field, including usage, IDs, reasoning and tool requests.\n Path(stem + ".json").write_text(json.dumps(data, ensure_ascii=False, indent=2), encoding="utf-8")\n print(json.dumps(data, ensure_ascii=False, indent=2))\n def save_blob(encoded, suffix, label):\n raw = base64.b64decode(encoded, altchars=b"-_", validate=True)\n ext = "png" if raw.startswith(b"\\x89PNG\\r\\n\\x1a\\n") else "jpg" if raw.startswith(b"\\xff\\xd8") else "webp" if raw[:4] == b"RIFF" and raw[8:12] == b"WEBP" else suffix\n file = Path(stem + "-" + label + "." + ext)\n file.write_bytes(raw)\n print("Saved", file)\n for index, block in enumerate(data.get("content") or []):\n print("Content", index, json.dumps(block, ensure_ascii=False))\n for choice in data.get("choices") or []:\n print("Choice", choice.get("index"), json.dumps(choice.get("message", choice.get("delta", {})), ensure_ascii=False))\n for index, item in enumerate(data.get("output") or []):\n print("Output", index, json.dumps(item, ensure_ascii=False))\n if item.get("type") == "image_generation_call" and item.get("result"):\n save_blob(item["result"], item.get("output_format") or "bin", "output-" + str(index))\n for ci, candidate in enumerate(data.get("candidates") or []):\n for pi, part in enumerate((candidate.get("content") or {}).get("parts") or []):\n print("Candidate/part", ci, pi, json.dumps(part, ensure_ascii=False))\n blob = part.get("inlineData") or part.get("inline_data")\n if blob and blob.get("data"):\n mime = blob.get("mimeType") or blob.get("mime_type")\n suffix = {"image/png":"png", "image/jpeg":"jpg", "image/webp":"webp", "audio/wav":"wav", "audio/mpeg":"mp3", "video/mp4":"mp4"}.get(mime, "bin")\n save_blob(blob["data"], suffix, "candidate-" + str(ci) + "-part-" + str(pi))\n\nwith client.chat.completions.stream(model='stepfun/step-3.5-flash',messages=[{"role":"user","content":"Explain observations and hypotheses in three sentences."}]) as stream:\n with Path("stream-events.jsonl").open("w",encoding="utf-8") as log:\n for event in stream:\n payload=event.to_dict(mode="json")\n log.write(json.dumps(payload,ensure_ascii=False)+"\\n"); log.flush()\n print(json.dumps(payload,ensure_ascii=False))\n final=stream.get_final_completion()\n save_result(final.to_dict(mode="json"),"stream-result")\njson or SSE
Keep every complete returned response, file and content part.
Keep every choice and its content/tool calls/reasoning. In SSE assemble deltas by choice/tool index, retain the final finish reason and usage.
Keep request/response IDs and headers. No generic text job retrieval URL is supplied.
| Field | Type |
|---|---|
Fieldchoices[].index | Typeinteger |
Fieldchoices[].message.content | Typestring|null |
Fieldchoices[].message.tool_calls | Typetool_call[] |
Fieldchoices[].message.reasoning_content | Typestring |
Fieldchoices[].message.reasoning_details | Typeobject|array |
Fieldchoices[].finish_reason | Typestring|null |
Fieldusage | Typeobject |
| Response | Condition | Next step |
|---|---|---|
Response400 · invalid_request_error | ConditionInvalid required fields, material representation or parameter value | Next stepCorrect the indicated fields before a new creation request. |
Ailoot Ultra stepfun/step-3.5-flash
Use the method paths shown above.
stepfun/step-3.5-flashStepFun’s Step 3.5 Flash is a sparse text model for reasoning, code and agent workflows. It activates about 11B parameters from its 196B-class model, combines sliding and full attention, and supports a 256K context.
This description covers the model’s capabilities. Available in Ailoot inputs, outputs and options are listed for the selected method below.
Step 3.5 Flash is StepFun’s sparse mixture-of-experts text model for reasoning and agent-oriented work. The published specification has 196.81 billion total parameters, including its prediction head, and activates about 11B parameters per token. It processes written instructions and conversation to generate text, code and proposed tool interactions.
Its 45-layer backbone combines sliding-window and full attention in a three-to-one ratio and supports a 256K context. Each expert layer has 288 routed experts plus a shared expert, with eight routed experts selected per token. A multi-token-prediction head is part of the producer’s efficiency design. These architectural choices describe the model; a particular application’s speed also depends on its serving setup and workload.
The central task areas are reasoning, coding and longer agent workflows. For a software assignment, provide the expected behavior, the relevant source and an actual failure or requested change. Ask for the proposed artifact and the checks needed to assess it. In a connected application, return the results of commands and checks before the model chooses its next step.
For long-context analysis, define the question and the sections of the material that matter. A useful report identifies its conclusion, the evidence supporting it and any missing observation. Keep the current objective and earlier confirmed findings available over follow-up turns so that the model can continue from the task’s state rather than reconstruct it from an incomplete prompt.
StepFun publishes integration and local-deployment recipes for coding and research applications. Tool execution belongs to the surrounding workflow: the model supplies the proposed action, and the application runs it and returns the outcome. Distinct converted or quantized artifacts have their own deployment conditions; the general model name does not choose one of them.
The producer’s known issues are concrete. The model can use long generation trajectories, and stability can decrease in specialized domains or extended multi-turn conversations. Reported symptoms include repetitive reasoning, mixed-language output and inconsistencies about time or identity. Specify the response language and the current task clearly, preserve the relevant observations and review the final artifact against the stated objective. Keep this text edition distinct from Step 3.7 Flash’s added vision encoder and image input.
POST /v1/messagestextjson, sse| Field | Type | Requirement | Values & limits | Default |
|---|---|---|---|---|
Fieldmodel | Typestring | RequirementRequired | Values & limits stepfun/step-3.5-flash | Default— |
Fieldmessages | Typemessage[] | RequirementRequired | Values & limits | Default— |
Fieldmessages[].role | Typestring | RequirementRequired | Values & limits user, assistant | Default— |
Fieldmessages[].content | Typestring | RequirementRequired | Values & limits | Default— |
Fieldmax_tokens | Typeinteger | RequirementRequired | Values & limits | Default— |
Fieldstream | Typeboolean | RequirementOptional | Values & limits | Defaultfalse |
Text · UTF-8 text
messages[].content string
| Parameter | Contract |
|---|---|
Parametercontent_type | Contractapplication/json |
Parameterrequired | Contractmodel, messages, max_tokens |
Parameteroptional_controls | Contractstream |
Parametermaterial_types | Contracttext |
Parametertext_file_material | ContractRead the actual UTF-8 document and put its text in the indicated input or message content string. |
Lifecycle: synchronous_or_streamed
Tariff references do not add request options. Supported parameters are listed for the selected method.
Match each charge to the conditions shown. Use one rate for each set of alternative configurations.
| Configuration | Rate schedule | Context tokens, more than | Context tokens, up to and including | Charge |
|---|---|---|---|---|
| ConfigurationBase token rates | Rate scheduleBase rate | Context tokens, more than— | Context tokens, up to and includingNo upper bound | Charge Input · Input tokens $0.00022 / 1K tokens Output · Output tokens $0.00066 / 1K tokens Input · Cache read $0 / 1K tokens Input · Cache write $0 / 1K tokens Input · Cache write, 1 hour — / 1K tokens |
| ConfigurationRequest-length tier 1 | Rate schedule— | Context tokens, more than0 | Context tokens, up to and includingNo upper bound | Charge Input · Input tokens $0.00022 / 1K tokens Output · Output tokens $0.00066 / 1K tokens Input · Cache read $0 / 1K tokens Input · Cache write $0 / 1K tokens Input · Cache write, 1 hour — / 1K tokens |
Ailoot reserves an estimated amount before a request. After the result, it settles the final charge from measured usage. Streaming settlement uses the final usage record. How reservation and settlement work →
{\n "model": "stepfun/step-3.5-flash",\n "max_tokens": 128,\n "messages": [\n {\n "role": "user",\n "content": "Summarize the incident report."\n }\n ],\n "stream": false\n}set -eu\n: "${AILOOT_API_KEY:?Set your Ailoot API key}"\n: "${AILOOT_TEXT_FILE:?Set your actual UTF-8 document}"\nexport AILOOT_TEXT_FILE\npython3 - <<'PY_REQUEST'\nimport json, os\nfrom pathlib import Path\n\nsource_file = Path(os.environ['AILOOT_TEXT_FILE'])\nif not source_file.is_file():\n raise SystemExit('Set AILOOT_TEXT_FILE to your actual UTF-8 document')\ntext = source_file.read_text(encoding='utf-8')\nif not text.strip():\n raise SystemExit('Choose a document containing text')\npayload = {'model': 'stepfun/step-3.5-flash', 'max_tokens': 128, 'messages': [{'role': 'user', 'content': 'Summarize the incident report.'}]}\npayload['messages'][0]['content'] = 'Summarize this material and quote supporting source passages.\\n\\n' + text\nPath('request.json').write_text(json.dumps(payload, ensure_ascii=False), encoding='utf-8')\nPY_REQUEST\ncurl --fail-with-body --silent --show-error https://api.ailoot.ai/v1/messages \\\n -H "x-api-key: $AILOOT_API_KEY" -H 'anthropic-version: 2023-06-01' -H 'Content-Type: application/json' \\\n --data-binary @request.json -D response-headers.txt -o result.json\npython3 - <<'PY_RESULT'\nimport json\nfrom pathlib import Path\n\nresult = json.loads(Path('result.json').read_text(encoding='utf-8'))\nprint(json.dumps(result, ensure_ascii=False, indent=2))\nPY_RESULT\nimport json, os\nfrom pathlib import Path\n\nsource_file = Path(os.environ['AILOOT_TEXT_FILE'])\nif not source_file.is_file():\n raise SystemExit('Set AILOOT_TEXT_FILE to your actual UTF-8 document')\ntext = source_file.read_text(encoding='utf-8')\nif not text.strip():\n raise SystemExit('Choose a document containing text')\npayload = {'model': 'stepfun/step-3.5-flash', 'max_tokens': 128, 'messages': [{'role': 'user', 'content': 'Summarize the incident report.'}]}\npayload['messages'][0]['content'] = 'Summarize this material and quote supporting source passages.\\n\\n' + text\nfrom urllib.request import Request, urlopen\nfrom urllib.error import HTTPError\n\napi_key = os.environ['AILOOT_API_KEY']\nif not api_key.strip():\n raise SystemExit('Set AILOOT_API_KEY before making a request')\nheaders = {'x-api-key': 'PLACEHOLDER_KEY', 'anthropic-version': '2023-06-01', 'Content-Type': 'application/json'}\nheaders['x-api-key'] = api_key\nrequest = Request('https://api.ailoot.ai/v1/messages', data=json.dumps(payload, ensure_ascii=False).encode('utf-8'), headers=headers, method='POST')\ntry:\n with urlopen(request, timeout=120) as response:\n raw = response.read()\n Path('response-headers.txt').write_text(str(response.headers), encoding='utf-8')\nexcept HTTPError as error:\n Path('result.json').write_bytes(error.read())\n Path('response-headers.txt').write_text(str(error.headers), encoding='utf-8')\n raise\nPath('result.json').write_bytes(raw)\nimport json\nfrom pathlib import Path\n\nresult = json.loads(Path('result.json').read_text(encoding='utf-8'))\nprint(json.dumps(result, ensure_ascii=False, indent=2))\nJSON or SSE
Keep every complete returned response, file and content part.
Keep all content blocks, thinking signatures and actual tool-use IDs. Assemble all SSE block deltas; a first text block is not the complete output.
Keep request/response IDs and headers. No generic text job retrieval URL is supplied.
| Field | Type |
|---|---|
Fieldid | Typestring |
Fieldmodel | Typestring |
Fieldcontent[] | Typetext|thinking|tool_use|other content block |
Fieldstop_reason | Typestring|null |
Fieldusage | Typeobject |
| Response | Condition | Next step |
|---|---|---|
Response400 · invalid_request_error | ConditionInvalid required fields, material representation or parameter value | Next stepCorrect the indicated fields before a new creation request. |
Ailoot Ultra stepfun/step-3.5-flash
Use the method paths shown above.
Technical example in English
Repair a stale accumulator default\n\nReview this Python function: def collect(value, items=[]): items.append(value); return items. Separate calls unexpectedly share earlier values. Propose a correction that preserves caller-supplied list mutation but creates a fresh list when the argument is omitted. Include tests for two omitted-argument calls and a call with an explicit list. Explain the changed default behavior.A corrected function and tests distinguishing fresh defaults from deliberate mutation of a supplied list.Omitted calls do not share state, while an explicit caller list retains the documented mutation behavior.