Anthropic through vertex does not forward header properly #1345
Description
What Happened?
There seems to be some issue when calling claude models through vertex_ai. To unify things, I am calling everything through the official anthropic sdk. In particular I am trying to access the computer_use tool, which require passing the additional anthropic_beta header.
What works:
- Use the anthropic API with anthropic endpoint
client = anthropic.Anthropic(api_key="dummy", base_url="https://api.portkey.ai/v1")
response = client.beta.messages.create(
model="@anthropic-default/claude-sonnet-4-20250514", # or another compatible model
max_tokens=1024,
tools=[
{
"type": "computer_20250124",
"name": "computer",
"display_width_px": 1024,
"display_height_px": 768,
"display_number": 1,
},
{
"type": "text_editor_20250124",
"name": "str_replace_editor"
},
{
"type": "bash_20250124",
"name": "bash"
}
],
messages=[{"role": "user", "content": "Save a picture of a cat to my desktop."}],
betas=["computer-use-2025-01-24"],
extra_headers=createHeaders(
api_key=xxx,
config=json.dumps(
{
"strategy": {"mode": "fallback"},
"targets": [
{
"override_params": {
"model": "@anthropic-default/claude-sonnet-4-20250514",
},
}
],
}
),
),
)
print(response)
What does not work
- to make vertex work the base_url must be "https://api.portkey.ai", note that the v1 is removed in the end
client = anthropic.Anthropic(api_key="dummy", base_url="https://api.portkey.ai/v1")
response = client.beta.messages.create(
model="@anthropic-default/claude-sonnet-4-20250514", # or another compatible model
max_tokens=1024,
tools=[
{
"type": "computer_20250124",
"name": "computer",
"display_width_px": 1024,
"display_height_px": 768,
"display_number": 1,
},
{
"type": "text_editor_20250124",
"name": "str_replace_editor"
},
{
"type": "bash_20250124",
"name": "bash"
}
],
messages=[{"role": "user", "content": "Save a picture of a cat to my desktop."}],
betas=["computer-use-2025-01-24"],
extra_headers=createHeaders(
api_key=PORTKEY_KEY,
config=json.dumps(
{
"strategy": {"mode": "fallback"},
"targets": [
{
"override_params": {
# "model": "@anthropic-default/claude-sonnet-4-20250514",
"model": "@gcp-vertex-default/anthropic.claude-sonnet-4@20250514",
},
}
],
}
),
),
)
print(response)
This will lead to endpoint not found error.
- however if we remove the v1
client = anthropic.Anthropic(api_key="dummy", base_url="https://api.portkey.ai")
response = client.beta.messages.create(
model="@anthropic-default/claude-sonnet-4-20250514", # or another compatible model
max_tokens=1024,
tools=[
{
"type": "computer_20250124",
"name": "computer",
"display_width_px": 1024,
"display_height_px": 768,
"display_number": 1,
},
{
"type": "text_editor_20250124",
"name": "str_replace_editor"
},
{
"type": "bash_20250124",
"name": "bash"
}
],
messages=[{"role": "user", "content": "Save a picture of a cat to my desktop."}],
betas=["computer-use-2025-01-24"],
extra_headers=createHeaders(
api_key=PORTKEY_KEY,
config=json.dumps(
{
"strategy": {"mode": "fallback"},
"targets": [
{
"override_params": {
"model": "@gcp-vertex-default/anthropic.claude-sonnet-4@20250514",
},
}
],
}
),
),
)
print(response)
Now portkey stops forwarding the anthropic_beta header. From the log I can see the original request has the header, but the final transformed one removed it. And even with things like forward_headers set, the header is still not forwarded
What Should Have Happened?
No response
Relevant Code Snippet
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Your Twitter/LinkedIn
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