charmbracelet / charmbracelet/fantasy
Config mismatch: Fantasy doesn't respect `context_window` from Catwalk provider configs
- Dominant language
- Go
- Stars
- 987
- Forks
- 137
- Avg merge
- 14h 41m
- Merged PRs (30d)
- 12
Description
### Description
5 Fantasy v0.7.0 appears to ignore the `context_window` value from Catwalk provider configurations when determining the token budget for AI agents. This results in agents always using a 200K token limit, even when the provider config explicitly specifies 1M tokens. In this specific case we were trying to enable Claude 4.5 with a 1M token header via Bedrock or Anthropic API
### Version
v0.7.0
### Environment
Fantasy version:v0.7.0 | Catwalk version: v0.16.1
Contributor guide
Research direction
Start by tracing Catwalk provider configuration handling for `context_window` and the code that determines Fantasy's agent token budget. Reproduce the v0.7.0 case with a 1M-token configuration, then verify that Bedrock or Anthropic API providers honor it instead of using the 200K default.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- aws, go
- Domain
- ai, backend
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100