Sample
verify pkg:pypi/typing-extensions@4.16.0 TypeIs type narrowing predicate
sha256:e0eb80c00f4e79d6846249cb2367b7c53e72b89639d3f959a0e81d954b101566
This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured.
How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people.
MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 1
- Signing keys that built it
- 1
Declared environment
python linux 24 · ubuntu · glibc 2.39 x64 python python pip
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| python 3.12 · linux alpine/x64 · docker ed25519:c1973797be207ac4 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · python@1python:3.12-alpine@sha256:d09d15e60962… |
2026-08-27 |
Case
HOW- Goal
- verify pkg:pypi/typing-extensions@4.16.0 TypeIs type narrowing predicate
- Packages
- Symbols
-
- typing_extensions.TypeIs
- Environment
- python
- Created
- 2026-08-27T21:43:43Z
Contract
- TypeIs special form supports type subscripting and get_origin get_args introspection
- TypeIs return annotations are preserved by get_type_hints
- TypeIs predicate functions correctly distinguish target types from non-target types at runtime
Files
- PROMPT.md
- csx.json
- requirements.txt
- sample.py
- spec.json
- test/contract.py
Origin Seeder
anonymous