finish_reason mix per provider, April 2026
finish_reason mix per provider, April 2026
Each bar is normalized to 100%. Click a legend item to isolate a series.
Which AI providers serve the most agentic traffic? In April 2026 Anthropic-direct returned `finish_reason = tool_calls` on 52% of successful completions on the Requesty gateway, about 2× the next provider and 17× higher than OpenAI direct. OpenAI Responses (26%), Vertex (Claude) (23%) and Azure (23%) formed a clear second tier. Splitting Vertex into Gemini and Claude cohorts shows the gap inside that route: Vertex (Claude) 23% vs Vertex (Gemini) 13%.
Why it matters`finish_reason = tool_calls` is the cleanest signal that a model was driving an agent loop rather than answering a chat prompt. Providers cluster into clear agentic and non-agentic tiers, which has direct implications for routing. Sending agent traffic to a non-agentic provider often produces shorter context windows and worse tool-following without users realising why their agent feels "dumber".
Key findings
- 01Anthropic-direct: 52% tool_calls, the highest agentic share on the platform.
- 02OpenAI Responses (26%), Vertex (Claude) (23%) and Azure (23%) form a clear second tier.
- 03Vertex (Claude) at 23% versus Vertex (Gemini) at 13%: same provider routing, different workload by an order of magnitude.
- 04OpenAI direct is at 3% tool_calls, 17× lower than Anthropic-direct.
- 05Bedrock Claude (7%) versus Anthropic-direct Claude (52%): same model, very different workload mix.
- 06NULL finish_reason correlates with successful=false. Moonshot 94% blank is a reliability outlier on that route.
Data
| Provider | tool_calls(percent) | stop(percent) | length(percent) | blank/error(percent) |
|---|---|---|---|---|
| Anthropic | 52.20% | 42.60% | 1.40% | 3.80% |
| OpenAI Responses | 25.90% | 71.00% | 1.00% | 2.10% |
| Vertex (Claude) | 23.40% | 56.20% | 5.30% | 15.10% |
| Azure | 22.60% | 57.50% | 0.40% | 19.50% |
| Vertex (Gemini) | 13.50% | 79.00% | 3.30% | 4.20% |
| Bedrock | 6.70% | 88.50% | 0.50% | 4.30% |
| Moonshot | 4.60% | 1.40% | 0.10% | 93.90% |
| OpenAI | 3.30% | 94.20% | 0.60% | 1.90% |
| xAI | 2.90% | 96.20% | 0.20% | 0.70% |
| DeepSeek | 1.50% | 94.50% | 2.20% | 1.80% |
Cite as
Cited in
- What the gateway saw in April 2026/blog/provider-trends-april-2026-agentic-share-latency