ScopeCall is open-source AI observability built for the cost and workflow questions every team running LLMs in production eventually has to answer:

Which prompt is responsible for that $4,200 spike yesterday?
Is it one runaway customer, or a broad shift in usage?
Did the latest prompt-version change make the bill worse, or better?
Which step of our agent workflow burned the tokens — the planning loop, the tool-use loop, or the final formatter?

ScopeCall answers those questions by capturing every LLM call your app makes via SDK instrumentation, recomputing its cost server-side from a bundled pricing table, and showing you the full prompt → customer → model → workflow path behind every dollar on your bill.

Why ScopeCall is different

	ScopeCall	Proxy-based tools	Closed-source vendors
Architecture	SDK instrumentation (in-process, no proxy)	Routes traffic through their cloud	Routes traffic through their cloud
Added latency	None — call goes provider-direct	10–50ms (proxy round-trip)	10–50ms
Data residency	Your hardware (self-hosted)	Their cloud	Their cloud
If their service goes down	Your app keeps working	Your app fails	Your app fails
License	Apache 2.0	Closed	Closed

Get started

Quickstart — 5 minutes from npm install to your first trace in the dashboard.
Installation — Self-host the full stack via Docker Compose.
TypeScript SDK — OpenAI, Anthropic, and Vercel AI SDK reference.
Python SDK — OpenAI and Anthropic — sync, async, streaming.

How it works

Your app (SDK)
    │  HTTP batch (every 5s)
    ▼
Rust ingest service           ← validates, authenticates, publishes to Kafka
    │
    ▼
Redpanda (Kafka-compatible)   ← durable buffer
    │
    ▼
Rust processor                ← recomputes cost, writes to ClickHouse
    │
    ▼
ClickHouse                    ← source of truth + hourly rollups

Go API (read-only)            ← serves the dashboard
    │
    ▼
Next.js dashboard             ← traces, cost explorer, flow map, alerts

The hot path (SDK → ingest → processor → ClickHouse) is Rust for throughput. Reads go through a Go API that's stateless and horizontally scalable. The dashboard never talks to ClickHouse directly — every read is API-mediated.

See Architecture for the detailed component breakdown, and the public repo at github.com/scopecall/scopecall for the source.

License

ScopeCall is licensed under Apache 2.0. Free for any use — self-hosted, modified, redistributed, or built on top of for commercial products. We monetize via the managed-cloud product (in development) and enterprise features (SSO, audit logs, SLA), not via licensing teeth.