Sample
Resolve relative URLs strictly per RFC 3986 with URL.join while relying on Client base_url normalization for prefix-preserving path concatenation
sha256:d0373902b8ccef8c40028ea3cf38618b01839ae31f872c4f5693809f8100af48
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Execution evidence
Declared environment and signed verification runs are separated so you can see exactly what this sample proves.
Evidence basisSigned contract pass
Verification receipts1
Verification levelL3_CONTRACT_PASS
Declared environment
- Execution context
- python
- Operating system
- linux
- Architecture
- x64
- Runtime
- python
- Language
- python
- Package manager
- pip
Verification-run environments
- Execution context
- python 3.12
- Operating system
- linux alpine · musl
- Architecture
- x64
- Runtime
- python 3.12
- Language
- python
- Package manager
- pip
- Execution
- container · docker
CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · python@1 · 2026-08-17
Case
- Goal
- Resolve relative URLs strictly per RFC 3986 with URL.join while relying on Client base_url normalization for prefix-preserving path concatenation HOW
- Packages
-
httpx 0.28.1
- Environment
- python
- Created
- 2026-08-17T06:39:20Z
Commonly assumed
Joining a relative path to an httpx.URL always appends to the full path prefix of the base URL
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- httpx.URL.join on a base path lacking a trailing slash replaces the final path segment rather than appending to it
- httpx.URL.join with a leading slash resolves to origin and discards all base URL path segments
- httpx.URL.join requires a trailing slash on the base URL and a relative path without leading slash to preserve base prefixes
- httpx.Client automatically appends a trailing slash to base_url and strips leading slashes from endpoints to preserve path prefixes
- httpx.URL.join with relative paths strips base query parameters while query-only joins preserve base paths
- httpx.URL.join handles dot segments strictly according to RFC 3986 relative path resolution algorithms
Files
- NOTES.md
- csx.json
- requirements.lock
- requirements.txt
- src/__init__.py
- src/url_resolver.py
- test/__init__.py
- test/contract.py
Download the source artifact (tar.gz)
Origin Seeder
csx-seed
Verification receipts
- python 3.12 · linux alpine/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · python@1 · 2026-08-17 · ed25519:d91480838ac982c9