TokenZero vs Vellum
Vellum is prompt engineering, workflows, evaluations and deployments in one platform. The matrix below says what each product is and how it bills; the only numbers are TokenZero's own measurements and prices.
TokenZero and Vellum differ in kind: Vellum is LLM application platform; TokenZero is a BYOK gateway whose engines reduce the provider bill and sign a receipt per call. Measured overhead is 1.52 ms p50; the cascade holds a 99.8% parity floor. On 100,000 gpt-6.1-sol calls, prefix caching saves $285 a month, $242 net of the 15% fee.
· Source: Vellum documentation at https://www.vellum.ai/pricing read 2026-10-26; TokenZero overhead from /benchmarks; prices from table 2026-10-26
At a glance
- Compared with
- Vellum (LLM application platform)
- TokenZero overhead
- 1.52 ms p50 / 3.42 ms p95 (measured, /benchmarks)
- BYOK
- TokenZero: always · Vellum: yes
- Receipts
- TokenZero: signed per call · Vellum: none
- Billing
- TokenZero: 15% of verified savings · Vellum: free tier, then seat and 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 Vellum: what each one is (vendor page read 2026-10-26)
| Dimension | TokenZero | Vellum |
|---|---|---|
| Category | BYOK savings gateway | LLM application platform |
| Hosting | hosted | hosted |
| Bring your own key | always; keys pass through and are never stored | yes |
| Open source | CLI, MCP server, audit core and GitHub Action Apache-2.0; gateway hosted | closed |
| How it bills | free up to $500/month routed; then 15% of verified savings, 3x-ROI-or-$0, capped plans | free tier, then seat and usage plans |
| Caching | prompt-cache formatting + exact and semantic response cache | none at the transport level |
| Routing | cascade to the cheaper sibling inside one provider, 99.8% parity floor, advisory by default | workflow-level model choice |
| 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 Vellum
your workflows; point the provider base URL at TokenZero where Vellum lets you.
- TokenZero is a transport-level gateway: no prompts move into a platform, no workflow is rewritten.
- Signed receipts show the saving on every call from day one.
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.
Questions people ask
What is the difference between TokenZero and Vellum?
Vellum is prompt engineering, workflows, evaluations and deployments in one platform. TokenZero is a BYOK gateway: you keep your workflows; point the provider base URL at TokenZero where Vellum lets you, and every call comes back with a signed receipt. TokenZero is a transport-level gateway: no prompts move into a platform, no workflow is rewritten.
What does switching from Vellum 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 Vellum and add TokenZero?
Usually yes: chain them by pointing Vellum's upstream at https://tokenzero.sh (or TokenZero's X-TokenZero-Upstream at Vellum); the receipt still prices the request at list and records what the gateway did.
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.