Summary

Mistral released Mistral Medium 3.5 in April 2026, a new frontier-class multimodal model. It is listed on the official Mistral models overview page and has a dedicated model card with published pricing, but is completely absent from the local catalog. This is a separate model from the existing mistral-medium-2505 (Mistral Medium 3.1) — it has different pricing ($1.5/$7.5 vs $0.4/$2) and a larger context window (256k vs 131k).

Gap Details

Three model IDs are missing:

Verified Fields

• Pricing: $1.50 / M input tokens, $7.50 / M output tokens (from model card)
• Context window: 256k tokens (from model card)
• Multimodal: Yes — described as "frontier-class multimodal model"
• Capabilities: Chat completions, function calling, structured outputs, agents, OCR, FIM, predicted outputs
• License: Modified MIT (open weights)
• Format: openai (Mistral uses OpenAI-compatible API)
• Provider: mistral

Fields NOT verified

• max_output_tokens — not explicitly published on the model card page; the downstream fix job should verify via the API
• reasoning / reasoning_budget — not stated on the model card

Official Sources

1. Model card page: https://docs.mistral.ai/models/model-cards/mistral-medium-3-5-26-04 — confirms API model IDs (mistral-medium-3.5, mistral-medium-3, mistral-medium-3-5-26-04), pricing ($1.5/$7.5), and 256k context
2. Models overview page: https://docs.mistral.ai/models/overview — lists Mistral Medium 3.5 as a current active model
3. Models index page: https://docs.mistral.ai/getting-started/models — lists Mistral Medium 3.5 with link to model card

Local Files Inspected

• packages/proxy/schema/model_list.json — grep for mistral-medium-3.5, mistral-medium-2604, mistral-medium-3-5 returns no matches
• The catalog currently has mistral-medium-latest (at $0.4/$2 — Medium 3.1 pricing) and mistral-medium-2505 (dated Medium 3.1 snapshot)

Verification Notes

• Source 1 (model card) verifies: model IDs, pricing, context window, multimodal capability
• Source 2 (overview) verifies: model is current/active, not deprecated
• Source 3 (index) verifies: model exists in the official catalog
• The pricing ($1.5/$7.5) is distinctly different from Medium 3.1 ($0.4/$2), confirming this is a separate model, not a rename

Relationship to Existing Issues

• Issue [BOT ISSUE] Missing Mistral new-generation models (mistral-large-3, mistral-small-4, ministral-3, codestral-2508, devstral-2) #448 (closed) covered older Mistral new-generation models (mistral-medium-3-1-25-08, etc.) — Medium 3.5 was not included as it was released after that issue
• Issue [BOT ISSUE] Mistral "latest" aliases have stale pricing, context windows, and incorrect API model IDs #486 (closed) covered stale -latest alias metadata — separate concern
• No open issue covers Mistral Medium 3.5

{
  "kind": "missing_model",
  "provider": "mistral",
  "models": ["mistral-medium-3.5", "mistral-medium-3", "mistral-medium-3-5-26-04"],
  "status": "active",
  "model_specs": {
    "mistral-medium-3.5": {
      "format": "openai",
      "flavor": "chat",
      "multimodal": true,
      "input_cost_per_mil_tokens": 1.5,
      "output_cost_per_mil_tokens": 7.5,
      "displayName": "Mistral Medium 3.5",
      "max_input_tokens": 256000,
      "available_providers": ["mistral"]
    },
    "mistral-medium-3": {
      "format": "openai",
      "flavor": "chat",
      "multimodal": true,
      "input_cost_per_mil_tokens": 1.5,
      "output_cost_per_mil_tokens": 7.5,
      "displayName": "Mistral Medium 3",
      "parent": "mistral-medium-3.5",
      "max_input_tokens": 256000,
      "available_providers": ["mistral"]
    },
    "mistral-medium-3-5-26-04": {
      "format": "openai",
      "flavor": "chat",
      "multimodal": true,
      "input_cost_per_mil_tokens": 1.5,
      "output_cost_per_mil_tokens": 7.5,
      "displayName": "Mistral Medium 3.5 (2026-04)",
      "parent": "mistral-medium-3.5",
      "max_input_tokens": 256000,
      "available_providers": ["mistral"]
    }
  },
  "source_urls": [
    "https://docs.mistral.ai/models/model-cards/mistral-medium-3-5-26-04",
    "https://docs.mistral.ai/models/overview",
    "https://docs.mistral.ai/getting-started/models"
  ]
}