affixly-surge-sdk 0.5.0

Lightweight cost-attribution wrapper for Anthropic, OpenAI, and Google Gemini Python SDKs

affixly-surge-sdk

Lightweight cost-attribution wrapper for the Anthropic, OpenAI, and Google Gemini Python SDKs. Track AI spend by product line, feature, and customer with a one-line import change — no proxy, no infrastructure, no code rewrite.

PyPI distribution name: affixly-surge-sdk. Python import name: surge_sdk. They differ because surge-sdk was already taken on PyPI by an unrelated project — the import name we control stays clean.

Using Node.js / TypeScript? See affixly-surge-sdk on npm — same interface, same event shape (source).

Install

pip install affixly-surge-sdk

Install alongside whichever provider SDK you use:

pip install "affixly-surge-sdk[anthropic]"   # Anthropic (Claude)
pip install "affixly-surge-sdk[openai]"      # OpenAI (GPT)
pip install "affixly-surge-sdk[gemini]"      # Google Gemini
pip install "affixly-surge-sdk[all]"         # All three

Quick start

from surge_sdk import anthropic, configure

configure(
    surge_api_url="https://your-surge-backend-url",
    surge_api_key="surge_sk_your_key_here",
    product_line="my-app",
)

client = anthropic.Anthropic(api_key="sk-ant-...")
response = client.messages.create(
    model="claude-sonnet-4-6",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello"}],
)
# Tracked automatically. No further code changes needed.

Get your surge_api_key from your Surge dashboard at Settings → SDK → Generate API key.

Per-call tags

Attribute spend to a specific feature or customer:

response = client.messages.create(
    model="claude-sonnet-4-6",
    max_tokens=1024,
    messages=[...],
    surge_tags={"feature": "summarize", "customer_id": "cust_abc123"},
)

Model overrides

Redirect calls to a different model than the call site declares — useful for multi-tenant plan tiering (Starter → Haiku, Business → Opus) without touching every call site:

# Global rule — applies to every call the SDK intercepts
configure(
    surge_api_url="...",
    model_overrides={
        "claude-opus-4-6": "claude-sonnet-4-6",   # all Opus calls become Sonnet
    },
)

# Per-call rule — wins over the global map
response = client.messages.create(
    model="claude-opus-4-6",                  # intent declared in code
    max_tokens=1024,
    messages=[...],
    surge_model=get_tenant_model(tenant_id),  # runtime tier resolution
    surge_tags={"feature": "chat", "customer_id": str(tenant_id)},
)

The dashboard logs both the requested and actual model on every override, plus a "Savings from model overrides" card showing the cost delta over time.

How it works

• The wrapper intercepts messages.create() (or the equivalent for OpenAI / Gemini), reads token counts from the response, and POSTs a usage event to your Surge backend on a background thread.
• Your AI calls go directly to the provider — no proxy, no added latency.
• If Surge is unreachable, the report is dropped silently. Your application is never affected.

Supported providers

Provider	Import	What's tracked
Anthropic	from surge_sdk import anthropic	messages.create(), messages.create(stream=True), messages.stream() (context manager)
OpenAI	from surge_sdk import openai	chat.completions.create(), chat.completions.create(stream=True)
Google Gemini	from surge_sdk import gemini as genai	models.generate_content(), models.generate_content_stream()

Both sync and async clients are supported for all providers (Anthropic and OpenAI; Gemini sync-only matches the upstream SDK's wrapping surface).

Streaming note for OpenAI: the SDK forces stream_options.include_usage=true on streaming calls so the final chunk carries cumulative usage. Callers iterating raw chunks will see one extra final chunk with usage populated — same shape as if you'd set it yourself.

Documentation

Full guide: see docs/getting-started.md.

License

MIT — see LICENSE.