Braintrust alternative
Braintrust is an evaluation platform with datasets, scorers, logging and a caching proxy. The matrix below says what each product is and how it bills; the only numbers are TokenZero's own measurements and prices.
TokenZero is a BYOK alternative to Braintrust: you keep your provider keys and list prices, add 1.52 ms p50 of measured overhead, and every call returns a signed receipt. On 100,000 reference calls on gpt-6.1-sol, cache formatting alone saves $285 a month, $242 net after the 15% fee; Braintrust issues no receipts.
· Source: Braintrust documentation at https://www.braintrust.dev/pricing read 2026-10-26; TokenZero overhead from /benchmarks; prices from table 2026-10-26
At a glance
- Compared with
- Braintrust (evals and logging with an AI proxy)
- TokenZero overhead
- 1.52 ms p50 / 3.42 ms p95 (measured, /benchmarks)
- BYOK
- TokenZero: always · Braintrust: yes (proxy)
- Receipts
- TokenZero: signed per call · Braintrust: none
- Billing
- TokenZero: 15% of verified savings · Braintrust: free tier, then usage plans
- Reference saving (gpt-6.1-sol, 100k calls)
- $285/month from prefix caching (computed)
- Net after 15% fee
- $242/month (computed)
- Parity floor
- 99.8%
- Free tier
- $500/month routed
- Vendor page read
- 2026-10-26
TokenZero vs Braintrust: what each one is (vendor page read 2026-10-26)
| Dimension | TokenZero | Braintrust |
|---|---|---|
| Category | BYOK savings gateway | evals and logging with an AI proxy |
| Hosting | hosted | hosted; hybrid deployment |
| Bring your own key | always; keys pass through and are never stored | yes (proxy) |
| Open source | CLI, MCP server, audit core and GitHub Action Apache-2.0; gateway hosted | proxy open source |
| How it bills | free up to $500/month routed; then 15% of verified savings, 3x-ROI-or-$0, capped plans | free tier, then usage plans |
| Caching | prompt-cache formatting + exact and semantic response cache | proxy cache |
| Routing | cascade to the cheaper sibling inside one provider, 99.8% parity floor, advisory by default | none |
| Savings receipts | Ed25519-signed per call, hash-chained, public key published | none |
| Gateway overhead | 1.52 ms p50 / 3.42 ms p95 (measured, /benchmarks) | not measured by TokenZero |
| Data retention | metadata only; ZDR mode available | see vendor docs |
| Net saving, 100k gpt-6.1-sol calls/month (prefix caching only) | $242 after fee | — |
What you keep when you move from Braintrust
evals and datasets; only the proxy base URL changes.
- Shadow parity is an in-production eval of cascade routing: a sample of routed requests is re-run on the original model and a pair is auto-disabled when parity drops.
- Receipts, not logs: metadata only, signed.
The change
OPENAI_BASE_URL=https://tokenzero.sh/v1
ANTHROPIC_BASE_URL=https://tokenzero.sh
# keep your provider keys exactly as they areThen npx -y @tokenzero/cli doctor to confirm the gateway, signer and pricing table, and see the switch guide.
Questions people ask
Is TokenZero a drop-in alternative to Braintrust?
Braintrust is an evaluation platform with datasets, scorers, logging and a caching proxy. TokenZero is a BYOK gateway: you keep evals and datasets; only the proxy base URL changes, and every call comes back with a signed receipt. Shadow parity is an in-production eval of cascade routing: a sample of routed requests is re-run on the original model and a pair is auto-disabled when parity drops.
What does switching from Braintrust to TokenZero save?
It depends on your prompts; on the reference workload (100,000 calls of 2,000 input with a 1,500-token static prefix and 300 output on gpt-6.1-sol, table 2026-10-26) prefix caching alone cuts $700 to $415 a month, $285 saved and $242 net after the 15% fee; exact-cache hits and cascade routing add to that. The receipts show the real figure.
Can I keep Braintrust and add TokenZero?
Yes. Braintrust is not a transport-level proxy, so it keeps working unchanged; TokenZero changes only the base URL your SDK calls.
How is the 15% fee computed?
On verified savings only: list-price baseline minus provider-reported actual cost, per signed receipt. A cycle whose savings are below 3x the fee is billed $0; Pro Cap and Scale Cap add monthly ceilings. The first $500 of routed spend each month is free.