---
title: "Rust vs Python parity"
description: "Honest feature matrix — partial counts as not implemented. What Peregrine/swift-rust can claim against OpenStack Swift."
---

> Documentation Index
> Fetch the complete documentation index at: https://docs.myswift.rs/llms.txt
> Use this file to discover all available pages before exploring further.

# Rust vs Python parity

> **Matrix scope**
>
> Rows below describe implemented or historically evidenced surfaces; they are
> not a production certificate for the `17adf0b` release line. G6 is GREEN, G7
> is not accepted, and production readiness is NO-GO. Partial, unit-only, and lab-only
> entries remain weaker than complete gate acceptance.

This page is the public, **strict** comparison of Peregrine `swift-rust` to
upstream OpenStack Swift. **Partial implementation is treated as not
implemented.** Product and fairness claims must stay inside what is green here.

Canonical long form in-repo:
[`docs/fairness-lab/RUST-VS-PYTHON-PARITY.md`](https://github.com/0smboy/Peregrine/blob/main/docs/fairness-lab/RUST-VS-PYTHON-PARITY.md).

**Historical snapshot: 2026-08-18 · Contabo lab · not PRODUCTION-GO-LIVE.**
Claim: **IMPLEMENTED_SUBSET_ONLY**. Dual-oracle 57-case last run
(post-GUARD, identical failing set to post-GATE / post-PY-XML-CT) `49/8` (`rc=1`).
Guard (`3d0138d5…`) was the recorded VIP generation for that run. Rust extras Python 2.33 does not
implement (object-ACL write, tagging/CORS mutate, RestoreObject) stay
implemented and are **not** forced to 501; the second scoreboard scores
them 7/7 against AWS semantics. Remaining 8 on the frozen runner =
7 extras + 1 Python residual (`x-amz-delete-marker` on current GET). Not
GREEN. Details:
[`docs/fairness-lab/S3-ALIGN-20260815.md`](https://github.com/0smboy/Peregrine/blob/main/docs/fairness-lab/S3-ALIGN-20260815.md).

On this site: methodology and scoreboard on [Dual-oracle](/dual-oracle) ·
client-visible behavior on the [S3 API reference](/s3-api) · which binary is
live on [Releases](/releases).

## Headline

| Area | Status |
|------|--------|
| Swift v1 core CRUD + common middleware | **Mostly implemented** |
| TempAuth + Keystone lab + EC + S3 core/MPU + bulk upload | **Implemented (lab-proven)** |
| S3 SigV4 + SigV2 + chunk-sig, multi-version, Transition metadata, WORM, ACP | **Implemented at the stated test levels** |
| Runtime-wired IAM and physical cold-tier routing | **Not implemented** (strict) |
| Arbitrary third-party Paste plugin loading | **Not implemented**; unknown filters fail closed |
| process_workers prefork | **Implemented** |
| eventlet/greenlet serving semantics | **Not implemented by design**; candidate uses native Hyper/Tokio async serving instead |
| native async HTTP/1.1 serving | **Implemented in candidate; acceptance open** (G3/G7 proof required) |
| Multi-primary auto-shrink | **Not implemented**; disabled by default |
| Multi-cluster sync / operator PEM / KMIP | **Not implemented** |

## Swift REST (v1)

| Capability | Python | Rust |
|------------|:------:|:----:|
| TempAuth v1.0 | yes | yes |
| Account / container / object CRUD | yes | yes |
| Range, conditionals, COPY, expiry | yes | yes |
| SLO / DLO (inline, streaming heartbeat, sync/async manifest-delete, concurrent HEAD, listing etag refetch) | yes | yes |
| TempURL (incl. ip_range) / FormPost / bulk **delete** | yes | yes |
| Bulk **upload** / extract-archive (tar/tar.gz/tar.bz2) | yes | yes |
| allow_account_management | yes | yes |
| Implemented Rust Paste pipeline filters | yes | yes |
| Full standard-filter behavior | yes | **no** (some names are explicit no-op aliases) |
| Unlimited arbitrary third-party Paste plugins | yes | **no** (no dynamic code loader) |

## Middleware

| Filter | Python | Rust |
|--------|:------:|:----:|
| catch_errors, gatekeeper, healthcheck, proxy_logging, cache, listing_formats | yes | yes |
| tempauth, copy, slo, dlo, quotas, versioned_writes, symlink, staticweb, ratelimit | yes | yes |
| name_check, etag_quoter, crossdomain, read_only, domain_remap, cname_lookup, backend_ratelimit | yes | yes (on-by-config) |
| keystoneauth + authtoken (lab Keystone) | yes | yes |
| s3api + s3token (core path) + ListParts | yes | yes |
| container-sync filter + daemon (HTTP/HTTPS + CA knobs) | yes | yes (unit; multi-cluster live not claimed) |
| encrypter / decrypter / keymaster | yes | yes (on-by-config; KMIP residual) |
| xprofile, list_endpoints | yes | yes (unit) |
| memcache/recon/healthcheck aliases as NamedPassthrough slots | yes | yes |
| Dynamic third-party plugin loading (`use=` / `plugin=`) | yes | **no** |

## S3

| Capability | Python | Rust |
|------------|:------:|:----:|
| SigV4 CRUD, List v1/v2, MultiDelete, MPU path, ListMPU, ListParts | yes | yes (lab) |
| **SigV2** (HMAC-SHA1 header + query) | yes | yes (unit; AWS vector) |
| s3token / EC2 → Keystone | yes | yes (lab) |
| Canned ACL + multi-rule CORS + object ?acl | yes | yes |
| aws-chunked / STREAMING-* (per-chunk HMAC enforced) | yes | yes (unit) |
| Versioning + multi-version data plane + ListVersions pagination | yes | yes (unit) |
| Lifecycle Expiration + Transition metadata (cold GET + restore) + AbortIncompleteMPU | yes | yes (unit) |
| Physical cold-tier storage-policy routing | yes | **no** (library unit only; proxy does not load the map) |
| Object Lock WORM + GOVERNANCE bypass header | yes | yes (unit) |
| Grant-header + ACP XML store/GET + enforcement | yes | yes (unit) |
| Multi-tenant local IAM policy engine | yes | **no** (library unit only; proxy does not load policies) |
| Hosted AWS IAM cloud product | yes | **no** |

## EC & consistency / platform

| Capability | Python | Rust |
|------------|:------:|:----:|
| EC policy encode/decode, multiphase PUT, ranged GET, heal | yes | yes (Linux `ec`) |
| Local sharder + manage-shard-ranges + shrink path | yes | yes |
| Multi-device same-host shrink helper | yes | yes (unit) |
| Multi-primary auto-shrink product | yes | **no** (disabled by default; cross-node safety unproven) |
| Cross-node multi-primary shrink over HTTP | yes | **no** (residual) |
| container-sync daemon (same-cluster) | yes | yes |
| Multi-cluster container-sync realm soak | yes | **no** |
| process_workers prefork | yes | yes |
| eventlet/greenlet serving semantics | yes | **no** (native async model instead; not an Eventlet clone) |
| native async HTTP/1.1 serve | no | candidate yes; G3/G7 acceptance open |
| Operator VIP TLS PEM go-live | yes | **no** (script GREEN; Contabo self-signed LAB) |
| Full ansible Python role twin | yes | partial (v3 subset) |

## Lab evidence anchors

- TempAuth func VIP **54/54**; soak **1h fail=0**
- S3 MPU deep **11/11**; EC2 s3token **green**
- **2026-08-07/08 SLO full audit:** Contabo live SLO matrix + s3cmd MPU KEEP
- **2026-08-08 hard9 residual:** Paste/xprofile, Transition, ACP+IAM, SLO concurrent — `tools/test-results/hard9-residual-wave-20260808/`
- **2026-08-08 hard residual wave:** unit evidence for SigV2 and several helper/library surfaces; see the 2026-08-09 correction in `tools/test-results/hard-residual-wave-20260808/`
- Operator TLS PEM **deferred** → not PRODUCTION-GO-LIVE

## How to use this matrix

- Fairness A/B: only compare surfaces marked **yes** on both sides.
- Marketing: do **not** say “full Swift compatibility.”

Source: https://docs.myswift.rs/parity/index.mdx