io.github.REX-codebase/fable-mode
Fable Mode
Mechanical write gates, evidence receipts, and adversarial review for AI coding agents.
alive probed 2026-10-14
14tools
8.9ktokens in Claude Opus 5.5
9.0ktokens in Claude Code
4.4 %of a 200k context window
4.9ko200k_base estimate
1.2 sto initialize
5 msto list tools
- Run it
- uvx fable-engine==1.3.5 (stdio, probed in a container with the network off)
- Host
- pypi.org
- Reports itself as
- fable-engine 1.3.5
- Capabilities
- tools
- Instructions
- none
- Claude count
- Claude Opus 5.5, measured 2026-10-14. Counted again when the tool definitions change. Method.
- Repository
- https://github.com/REX-codebase/fable-mode
- Registry
- active, updated 2026-09-16 · registry entry
- Reachable
- 1 of the last 1 probe
Most expensive tools
| Tool | Tokens (o200k) | Share of this server |
|---|---|---|
| fable_session | 3 507 | 72 % |
| browser_navigate | 185 | 4 % |
| browser_snapshot_layers | 163 | 3 % |
| browser_type | 151 | 3 % |
| browser_open | 119 | 2 % |
Badge and feed
[](https://mcpcost.ulehla.dev/s/io.github.REX-codebase/fable-mode)
An entry for every probe that changed the result, the tool count or the token cost: Atom feed. Add it to a feed reader or a Slack RSS app to hear when the server stops answering or its tool set grows.