Head to head · Inference decision · October 2026 research run
OpenAI Decisions API vs Vela 2.0
OpenAI Decisions API scores 71.5 (BB) on agent readiness against Vela 2.0's 66.5 (B), and leads in 4 of 7 scored categories. Vela 2.0 leads on payments & pricing and maintenance & community. Both do inference decision.
Which one, for what
Good for High-volume yes or no checks, routing among fixed options and rubric scoring over text and images, for teams already on an OpenAI key.
Ahead on
- Schema & documentation, 89 against 78
- Agent ergonomics, 87 against 79
- Security & auth, 83 against 60
- Transparency & trust, 83 against 48
Also in its favour
- Agent-ready, a grade of BB or better
- A hosted endpoint, with nothing to install
Watch for
Public beta released on 6 October 2026. The guide expects general availability in the coming weeks and gives no date
Vela 2.0 B
Good for Self-hosted routing and guardrail checks in one call, where span offsets for personal data or unsupported claims matter.
Ahead on
- Payments & pricing, 60 against 30
- Maintenance & community, 84 against 77
Also in its favour
- No key needed to call it
- Open source
Watch for
No version tags on the four Hub repositories, and the 4B and 9B weights were replaced in place on 3 October 2026
Score by category
| Category | Weight this run | OpenAI Decisions API | Vela 2.0 | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 53 | 57 | Vela 2.0 +4 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 89 | 78 | OpenAI Decisions API +11 |
| Agent ergonomics | 13%16.2 | 87 | 79 | OpenAI Decisions API +8 |
| Security & auth | 14%17.5 | 83 | 60 | OpenAI Decisions API +23 |
| Payments & pricing | 10%12.5 | 30 | 60 | Vela 2.0 +30 |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 77 | 84 | Vela 2.0 +7 |
| Transparency & trust | 7%8.8 | 83 | 48 | OpenAI Decisions API +35 |
| Negative events | ≤15 | 0 | 0 | |
| Total | 71.5 · BB | 66.5 · B |
Facts side by side
| Fact | OpenAI Decisions API | Vela 2.0 |
|---|---|---|
| Kind | Model API | Model API |
| Vendor | OpenAI | vLLM Semantic Router project and KR Labs |
| Hosted endpoint | https://api.openai.com/v1/decisions | no (local only) |
| Transports | HTTP | HTTP |
| Auth | API key | None |
| Pricing | Pay per use | Free |
| Price for inference decision | $0.10 per 1M tokens | free |
| x402 | no | no |
| Licence | Proprietary service under OpenAI's services agreement. The official SDKs are Apache-2.0 | Apache-2.0 (weights, code and documentation). The 0.3B's tokeniser keeps the Gemma Terms of Use, and training data keeps its own licences |
| Read-only variant documented | no | no |
| llms.txt | yes | no |
| Last release | 2026-10-06 | 2026-10-06 |
| Terms last updated | couldn't be read | no document linked |
| Privacy policy last updated | couldn't be read | no document linked |
| Customer content may train models | couldn't be read | |
| Terms restrict automated access | couldn't be read | |
| Terms restrict benchmarking | couldn't be read | |
| Terms or service can change without notice | couldn't be read | |
| Arbitration or class-action waiver | couldn't be read | |
| Popularity | 32k stars | 6.1k stars |
Verdicts
OpenAI Decisions API
Typed predicate, choice and score answers with probabilities, up to 200 questions a call, at $0.10 per million input tokens with no output charge. It is a public beta released on 6 October 2026, with one model alias, no dated snapshot, no Batch route and no SLA found.
Vela 2.0
One self-hosted call answers routing, prompt-attack, personal-data and unsupported-claim questions with probabilities and character offsets, under Apache-2.0 with SHA-256 manifests. The models are days old and carry no Hub version tags, and the three larger sizes keep 74 to 89 per cent of their Decision 2.0 bases on the Jev Decision Index by the authors' figures.
Before you call either
OpenAI Decisions API
- Put independent questions about one input in a single
questionsarray. Send a separate request when a question depends on an earlier answer - Check each answer's
typebefore reading it. A question can come back asrefusalwhile the others in the same request are answered - Encode images as base64 data URLs. Hosted URLs and
file_idinputs are rejected - Give a
choicequestion a fallback value such asother, and set thresholds from your own labelled examples - Use Python SDK 3.26.0 or JavaScript 7.30.0 or later, and follow
Retry-Afteron 429 and 503
Vela 2.0
- Pin a commit hash with
revision=when loading from the Hub. The repositories have no tags andmainhas changed since launch - Send the served name in
model, for examplevllm-sr/Vela-2.0-4B. The bundled server answers 422 to any other name - Name span questions
pii,haluortoxic, or set"head": "router", to get the trained router head. Other labels go to the broad head - Keep input under 16,384 tokens a sequence (8,192 on the 0.3B). The bundled server answers 413 when the questions alone don't fit
- Set
VELA2_API_KEYbefore binding the bundled server beyond 127.0.0.1, and keep the model runtime on a trusted network
Questions
Which is better for AI agents, OpenAI Decisions API or Vela 2.0?
OpenAI Decisions API scores 71.5 (BB) on agent readiness against Vela 2.0's 66.5 (B), and leads in 4 of 7 scored categories. Vela 2.0 leads on payments & pricing and maintenance & community.
Which is cheaper for inference decision, OpenAI Decisions API or Vela 2.0?
Vela 2.0, at free against $0.10 per 1M tokens for OpenAI Decisions API. These are the vendors' published prices for the job.
Do OpenAI Decisions API and Vela 2.0 need an API key?
OpenAI Decisions API needs an API key. Vela 2.0 needs no key.
Can an agent call OpenAI Decisions API and Vela 2.0 without installing anything?
OpenAI Decisions API has a hosted endpoint at https://api.openai.com/v1/decisions. No hosted endpoint is listed for Vela 2.0.
Are OpenAI Decisions API and Vela 2.0 open source?
No open-source release is listed for OpenAI Decisions API. Vela 2.0 is open source (Apache-2.0 (weights, code and documentation). The 0.3B's tokeniser keeps the Gemma Terms of Use, and training data keeps its own licences).
Other comparisons with OpenAI Decisions API or Vela 2.0
Machine-readable
- This page as Markdown
/compare/openai-decisions-api-vs-vela.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/openai-decisions-api.json·/api/v1/tools/vela.json - From a terminal
anchor compare openai-decisions-api vela(the CLI) - Over MCP
compare_tools {"a": "openai-decisions-api", "b": "vela"}at/mcp, no key