Custom model session starts with a 200K window (99% full) until /model → Default switches it to [1m]

Versions: Claude Code v2.1.272, ollama 0.34.0, macOS 26

Steps

1. cd <project> && ollama launch claude
2. In the launcher pick glm-5.3:cloud, listed as "Long-horizon coding and agentic engineering with deep reasoning and a 1M context" (real context: ollama show glm-5.3:cloud → context length 1048576).
3. /context → glm-5.3:cloud · 197.2k/200k tokens (99%), Auto-compact window: 200k tokens, "Context is 99% full" on an empty session (messages: 69 tokens).
4. /model → the list shows 1. Default (currently glm-5.3:cloud[1m]), 2. glm-5.3:cloud ✔ Custom Opus model, 4. glm-5.3:cloud Custom Sonnet model, 5. glm-5.3:cloud Custom Haiku model.
5. Select 1. Default → "Set model to glm-5.3:cloud[1m]".
6. /context → glm-5.3:cloud[1m] · 215.2k/1m tokens (22%), Auto-compact window: 1m tokens.

Expected: the session starts with the 1M window, or the picker makes clear that the entries named glm-5.3:cloud give 200K while Default gives 1M.

Actual: the launched session runs on a 200K window and is at 99% before the first message. The same model gets 1M only after re-selecting Default in /model.

Verbatim output

Launcher — I pick glm-5.3:cloud, described as "a 1M context", and expect a 1M window, not 200K:

➜  cloudshot git:(main) ollama launch claude
Select model for Claude Code: Type to filter...

  Recommended
    glm-5.3-flash:cloud
      Fast reasoning for coding and agentic workloads with 1M context and native image understanding
  ▸ glm-5.3:cloud
      Long-horizon coding and agentic engineering with deep reasoning and a 1M context
    deepseek-v4.1-flash:cloud
      Fast coding and agentic tool use with 1M context and native image understanding
    gemma4:31b-cloud
      Agentic workflows and multimodal reasoning
    gemma4:26b
      Agentic workflows and multimodal reasoning, ~19GB, (not downloaded)

Right after ollama launch claude → glm-5.3:cloud:

❯ /context
  ⎿  Context Usage
     ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁   glm-5.3:cloud
     ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁   197.2k/200k tokens (99%)
     ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁
     ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁   Estimated usage by category
     ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁   ⛁ System prompt: 2k tokens (1.0%)
     ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁   ⛁ System tools: 41k tokens (20.5%)
     ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁   ⛁ MCP tools: 142.4k tokens (71.2%)
     ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁   ⛁ Custom agents: 173 tokens (0.1%)
     ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁   ⛁ Memory files: 9.5k tokens (4.8%)
     ⛁ ⛁ ⛀ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛀   ⛁ Skills: 2.1k tokens (1.0%)
                           ⛁ Messages: 69 tokens (0.0%)
                           ⛝ Autocompact buffer: 33k tokens (16.5%)

     Auto-compact window: 200k tokens

It switches to 1M only if I open /model and select 1. Default:

  Select model
  Switch between Claude models. Your pick becomes the default for new sessions. For other/previous model names, specify with --model.

  ❯ 1. Default (recommended)  Use the default model (currently glm-5.3:cloud[1m])
    2. glm-5.3:cloud ✔        Custom Opus model
    3. Fable                  Fable 5.1 · Most capable for your hardest and longest-running tasks · $10/$50 per Mtok
    4. glm-5.3:cloud          Custom Sonnet model
    5. glm-5.3:cloud          Custom Haiku model

  ◐ Medium effort ←/→ to adjust

  Enter to set as default · s to use this session only · Esc to cancel

After that:

❯ /model
  ⎿  Set model to glm-5.3:cloud[1m] (default) and saved as your default for new sessions

❯ /context
  ⎿  Context Usage
     ⛀ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁   glm-5.3:cloud[1m]
     ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛁ ⛀ ⛁ ⛁ ⛁   215.2k/1m tokens (22%)
     ⛀ ⛁ ⛁ ⛁ ⛀ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   Estimated usage by category
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ System prompt: 2k tokens (0.2%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ System tools: 35.2k tokens (3.5%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ MCP tools: 142.4k tokens (14.2%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ Custom agents: 173 tokens (0.0%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶   ⛁ Memory files: 9.5k tokens (1.0%)
     ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛝ ⛝ ⛝ ⛝ ⛝ ⛝ ⛝   ⛁ Skills: 7.8k tokens (0.8%)
                                               ⛁ Messages: 18.1k tokens (1.8%)
                                               ⛶ Free space: 751.8k (75.2%)
                                               ⛝ Autocompact buffer: 33k tokens (3.3%)

     Auto-compact window: 1m tokens