Inception launches Mercury 3 with a 1-million-token context window
Inception's Mercury 3 diffusion model launches with tool calling and structured outputs. Providers report generation above 1,000 tokens per second, while Parallel finds it Pareto-optimal in its web research tests.

TL;DR
- Mercury 3 pairs a 1M-token context window with reported generation above 1,000 tokens/s, according to OpenRouter's launch announcement.
- Tool calling and structured outputs are available through AI Gateway, per Vercel's announcement.
- Web research reaches Parallel's price-quality frontier, according to its first diffusion-model evaluation.
Inception scaled Mercury 3 to more than 40 times Mercury 1's parameter count while retaining similar throughput. OpenRouter lists a 131,072-token completion limit beneath that headline 1M context window.
Parallel token refinement
Mercury 3 generates and refines tokens in parallel instead of decoding strictly one token at a time. Inception reports 1,068 output tokens/s on NVIDIA GPUs; OpenRouter's live performance panel shows a 244-token/s median.
The most compelling deployment pattern is a fast worker beneath a smarter orchestrator, the pairing tri_dao said he has wanted.
Medium-reasoning benchmarks
Inception compares Mercury 3 with the speed-optimized GPT-6 Luna and Claude Haiku 5.5 tier, as TheRundownAI's launch summary notes. All three models use medium reasoning in the comparison.
Parallel Search evaluation
Mercury 3 is the first diffusion LLM Parallel has tested with its search tool. The company places it on its web-research price-quality frontier.
Parallel reports these results in its October 19 leaderboard:
- Mercury 3: 63.6 Search Intelligence score; $43.40 per 1,000 tasks.
- Claude Haiku 5.5: 62.9; $24.30 per 1,000 tasks.
Adding search raises Mercury 3's score from 28.1 to 63.6, a 35.5-point gain.
Agent wall-clock time
In a one-prompt comparison at medium reasoning, daniel_mac8 timed Mercury 3 through OpenRouter at 4.3 seconds versus Haiku 5.5 through claude.ai at 8.0 seconds.
The same prompt through two services: Mercury 3 finishes in 4.3 seconds, Haiku 5.5 in 8.0 seconds.
Inception also published customer measurements:
- TinyFish AI reported 50% success across 50 live Mind2Web navigation tasks, ahead of GPT-6.1-Sol, with token volume and agent-step count matching a frontier model in its production harness.
- Octen AI reported 0.9-second median generation and 2.2-second median end-to-end response time in its Sense API tests.
API access and launch pricing
Context expands from 260K tokens in Mercury 2.5 to 1M in Inception's specifications.
- API availability: Inception, OpenRouter, Baseten, and Vercel AI Gateway.
- Model slug:
inception/mercury-3on OpenRouter and AI Gateway. Vercel's integration usesAI_GATEWAY_API_KEY. - Tools and JSON:
toolsandtool_choicefor function calling; JSON Schema inresponse_formatfor structured outputs, per OpenRouter's API listing. - Venice: anonymous access through its model page.
At Inception's 50% launch discount, pricing is $0.10/M input and $0.35/M output; standard rates are $0.20 and $0.70 respectively. OpenRouter lists cache reads at $0.01/M.