Ornith-1.5 35B-A3B
The mid-size mixture-of-experts member of the Ornith-1.5 family. It activates only ~3B parameters per token, yet significantly outperforms its similar-sized peer Qwen 3.6-35B across all coding and agentic benchmarks, and outperforms dense models such as Gemma 4-31B and Muse Glimmer-30B by wide margins on agentic coding.
Ornith AI’s own description of the model, from
Ornith-1.5-35B-A3B model card . Served here as ornith-ai/ornith-1.5-35b-a3b.
What Ornith AI built it for
in the vendor’s words- “Ornith-1.5-35B-A3B excels in tool-calling and agentic coding.”
- “Ornith-1.5-35B-A3B is optimized for terminal-based coding agents.”
Quoted from Ornith-1.5-35B-A3B model card, retrieved 23 Aug 2026. A reasoning model with no non-thinking arm documented: the card publishes one set of scores, not a thinking/non-thinking split.
Published benchmarks
Ornith AI’s figures, not ours| Benchmark | What it measures | Score | How Ornith AI ran it |
|---|---|---|---|
| Terminal-Bench 2.1 Terminus-2 harness | Agentic terminal coding | 67.8 | Harbor/Terminus-2 framework, parser=json, temperature=1.0, top_p=1.0, 128K context window; 4-hour timeout, averaged over 5 runs. Mode: reasoning on (the model's only documented mode). |
| SWE-bench Verified | Real-world software engineering | 79 | OpenHands harness, temperature=1.0, top_p=0.95, 256K context window; git history removed and network disabled as anti-hacking safeguards. Mode: reasoning on (the model's only documented mode). |
| SWE-bench Pro | Real-world software engineering, harder split | 59.6 | OpenHands harness, temperature=1.0, top_p=0.95, 256K context window. Mode: reasoning on (the model's only documented mode). |
| MCP-Atlas | Tool use over MCP servers | 70.2 | 500-task public subset, 10-minute timeout per task, Claude 4.8 Opus as judge. Mode: thinking mode (the card states all models were evaluated in thinking mode for this row). |
| ClawEval | Agentic coding on real-user tasks | 72.5 | temperature=0.6, 256K context window. Mode: reasoning on (the model's only documented mode). |
| GPQA Diamond | Graduate-level science reasoning | 89.2 | The card states no separate harness or sampling for this row beyond the family-wide 5-run average. Mode: reasoning on (the model's only documented mode). |
| HLE no tools | Humanity's Last Exam, frontier reasoning | 25.6 | Claude 4.6 Opus as the judge model; the card also publishes 33.4 with tools. Mode: reasoning on (the model's only documented mode). |
Every score above is Ornith AI’s own published result for this model, copied from Ornith-1.5-35B-A3B model card on 23 Aug 2026 — we did not run these benchmarks and we do not restate them as our own. “All results reported for Ornith-1.5 are averaged over five independent runs.” Each vendor ran its own harness with its own judge, so these tables are not a league table: scores from two different cards are not comparable, even where the benchmark name matches. Each model here shows only its own maker’s table, for that reason.
Recommended usage
what Ornith AI recommendsSampling
For general tasks, Ornith AI recommends temperature=0.6, top_p=0.95, top_k=20. That is what this
endpoint sends when your request omits them, so the default request shape
is the vendor’s recommendation rather than ours. An explicit value in
your request always wins.
Ornith AI publishes a second set for reproducing the vendor's published benchmark scores:
temperature=1.0.
Send those yourself if that is your case — they are not the default here.
Thinking
Reasoning is always on in the vendor's own recipes — the card documents no request-side switch to turn it off, and the serving recipes it publishes enable a reasoning parser so the chain of thought comes back in a separate reasoning_content field rather than inline.
On this endpoint: Reasoning is on or off, nothing in between: on by default for hard problems, off with reasoning_effort "none" — the low-latency shape for voice and interactive turns.
Context length
Ornith AI gives the native window as 262,144 tokens, which is what we serve — the full checkpoint window, with input and output sharing it. Beyond the native window the vendor points at YaRN RoPE scaling — factor 4.0 takes the usable window to roughly 1M tokens — but recommends against leaving it on.
Ornith AI’s caution on extending it: “Open-source runtimes implement YaRN statically: the same scaling factor is applied to every request regardless of its length, which can slightly hurt quality on ordinary-length inputs. Only enable rope_scaling when your workload genuinely needs the longer window, and size factor to match it” We serve the native window and do not enable static RoPE scaling, so ordinary-length requests are not paying that cost.
What to point it at
Ornith AI names these workloads for this model:
- “understand large codebases, automate tedious work, and ship faster”
- “works out of the box with standard agent frameworks”
Recommendations on this page are Ornith AI’s, from Ornith-1.5-35B-A3B model card, retrieved 23 Aug 2026. We default to them rather than to a house preference; where our default would differ, this page says so.
What it does on this endpoint
our measurements · not vendor figures
These three are ours, measured on the live endpoint — observations, not service
guarantees, and not to be confused with the vendor scores above. The protocol,
the vantages, the build each figure is pinned to and how to check it against the
system_fingerprint in your own response are all on
the measurements page. Run your own and use
those instead.
Price
per million tokens · no request fee · no subscription| Input | Cached input | Output |
|---|---|---|
| $0.25 | $0.09 | $1.20 |
One price, no tiers. Cache hits are applied automatically and reported per
response as cached_tokens. Full price sheet
and worked examples.
Capabilities
ornith-ai/ornith-1.5-35b-a3bThree API formats, one base URL
OpenAI Chat Completions, OpenAI Responses, and Anthropic Messages — all
served from https://api.tiyuvta.ai/v1. Point an existing client at
it and set the model id; there is no product-specific SDK.
Tools and structured output
tools and tool_choice, JSON mode, and JSON
schema via response_format. The tool-call round trip is
part of the release gate on every deploy.
Vision
Images go in as image_url content parts and bill as ordinary
input tokens — vision costs nothing extra.
Reasoning: on or off
Reasoning is on or off, nothing in between: on by default for hard problems, off with reasoning_effort "none" — the low-latency shape for voice and interactive turns.
Prompt caching
Continuing a conversation reuses its prefix and bills the cached rate for what actually hit — reported per response, priced per token, no hit-rate promises.
Exactness-gated serving
Speculative decoding is verified byte-identical to plain decode on the serving configuration before a build takes traffic — speed never changes the output. The correctness gates.
Where it fits best
use it for- The default choice: the flagship — fastest first token, highest output speed, lowest price here
- Agents and tool-calling loops, where output tokens are the bill
- High-throughput pipelines — extraction, generation, summarization at volume
- Voice and interactive products: under 200 ms median to the first content token from both US coasts with reasoning off
Need a reasoning-effort dial or video input? See Qwen3.8 27B — same key, same balance.
First request
ornith-ai/ornith-1.5-35b-a3bcurl https://api.tiyuvta.ai/v1/chat/completions \
-H "Authorization: Bearer $TIYUVTA_KEY" \
-H "Content-Type: application/json" \
-d '{"model": "ornith-ai/ornith-1.5-35b-a3b",
"messages": [{"role": "user", "content": "Hello"}]}' The default request reasons before it answers, at Ornith AI’s recommended sampling — best quality for hard problems.
curl https://api.tiyuvta.ai/v1/chat/completions \
-H "Authorization: Bearer $TIYUVTA_KEY" \
-H "Content-Type: application/json" \
-d '{"model": "ornith-ai/ornith-1.5-35b-a3b",
"reasoning_effort": "none",
"messages": [{"role": "user", "content": "Hello"}]}' reasoning_effort: "none" makes the first streamed
token the answer itself — the measured 120 ms first-token
figure above is this request shape.
- Weights and vendor sources
- huggingface.co/ornith-ai/Ornith-1.5-35B-A3B, MIT. Ornith AI trained this model; we serve it at its full native context in NVFP4 4-bit weights (self-published GGUF, first NVFP4 of this model). Benchmark scores and usage recommendations on this page come from Ornith-1.5-35B-A3B model card and Ornith-1.5: From Self-Scaffolding to Self-Improvement , retrieved 23 Aug 2026.
- Machine-readable metadata
-
GET https://api.tiyuvta.ai/v1/modelsfor supported parameters, and the provider feed atGET https://api.tiyuvta.ai/models?schema=openrouter. - Rate limits
- Per account, for abuse control, raised on request — capacity scales with demand rather than sitting behind a published ceiling.