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Release Notes

Latest Release — v1.3.0

Cello v1.3.0 — Async Rework, Native Data Layer, Plugin Audit & Three-Pillar Upgrades (July 2026)

A large release built around Cello's three pillars — Speed, Simplicity, Security.

Highlights:

  • Persistent asyncio loop — async def handlers run on one long-lived loop (loop-bound resources survive; GIL released during I/O)
  • Native data layer + ORM — real Postgres pool & async Redis client (incl. rediss:// TLS) plus a built-in async ORM (replaces the old mock layer)
  • Full enable_* plugin audit — health-check/GraphQL/Prometheus 404s, BasicAuth challenge, JWT iat, security-headers config, and a timeout panic all fixed
  • Three-pillar upgrades — full security headers (CSP, Permissions-Policy, cross-origin isolation), gzip-compressed cache HITs, declarative body= request validation
  • Security & DoS hardening — CSRF/skip-path/CORS/BasicAuth/SSE fixes, body-size limits & header/body/handler timeouts
  • Upgrade from v1.2.x — additive API; async apps relying on a fresh loop per request should review the migration note

Full v1.3.0 Release Notes Migration Guide

Version Timeline

timeline
    title Cello Framework Releases
    2026-07 : v1.3.0 - Async Rework, Native Data Layer, Plugin Audit & Three-Pillar Upgrades
    2026-06 : v1.2.4 - Critical Fix: async def Handlers
            : v1.2.3 - Full Middleware Python API & Docs Fixes
            : v1.2.2 - Security & Bug Fixes (CSRF, skip_path, rate limiter)
            : v1.2.1 - Critical Bug Fixes (server bind, ProblemDetails export)
            : v1.2.0 - Redis Lua Scripting & Rust-Native AsyncClient
            : v1.1.0 - MiniJinja Jinja2-Compatible Templates
    2026-02 : v1.0.1 - Cross-Platform & Compatibility Patch
            : v1.0.0 - Production Ready (Stable)
            : v0.10.0 - Event Sourcing, CQRS, Saga
            : v0.9.0 - GraphQL, gRPC, Message Queues
            : v0.8.0 - Database Pooling, Redis, Transactions
    2026-01 : v0.7.0 - OpenTelemetry, Health Checks
    2025-12 : v0.6.0 - Smart Caching, Adaptive Rate Limiting
    2025-10 : v0.5.0 - DI, Guards (RBAC), Prometheus
    2025-08 : v0.4.0 - JWT, Sessions, Cluster Mode
    2025-06 : v0.3.0 - WebSocket, SSE, Blueprints

All Releases

  • v1.3.0 — Async Rework, Data Layer & Upgrades

    Persistent asyncio loop, native data layer + ORM, full plugin audit, three-pillar upgrades (full security headers, compressed cache, body= validation), and DoS hardening.

    July 2026

    Release Notes

  • v1.2.4 — Critical Async Fix

    Fixes all async def handlers returning 500 since v1.2.1. Coroutines now driven via spawn_blocking + asyncio.run().

    June 2026

    Release Notes

  • v1.2.3 — Full Middleware Python API

    cello.middleware module, app.use() dispatcher, 6 new enable_* methods, all doc import paths corrected.

    June 2026

    Release Notes

  • v1.2.2 — Security & Bug Fixes

    Critical CSRF HttpOnly fix (broke all AJAX apps), auth skip_path prefix bypass fix, rate limiter fixed-window reset bug.

    June 2026

    Release Notes

  • v1.2.1 — Critical Bug Fixes

    Server port never bound, ProblemDetails missing from Python export, And/Or guard *args style, HttpOnly removed from CSRF cookie.

    June 2026

    Release Notes

  • v1.2.0 — Redis Lua & AsyncClient

    Redis Lua scripting (eval, evalsha, script_load), Rust-native AsyncClient backed by reqwest + Tokio — GIL never held during HTTP I/O.

    June 2026

    Release Notes

  • v1.1.0 — MiniJinja Templates

    Jinja2-compatible template engine via minijinja Rust crate. app.enable_templates(), app.render(), globals, auto HTML-escaping.

    June 2026

    Release Notes

  • v1.0.1 — Cross-Platform & Compatibility Patch

    Windows multi-worker subprocess mode, ARM JSON fallback, async guard/cache/blueprint compatibility, export completeness.

    February 2026

    Release Notes

  • v1.0.0 — Production Ready

    Stable release with performance optimizations, API stability guarantees, and the complete feature set.

    February 2026

    Release Notes

  • v0.10.0 — Advanced Patterns

    Event Sourcing, CQRS, and the Saga Pattern for distributed transaction coordination.

    February 2026

    Release Notes

  • v0.9.0 — API Protocols

    GraphQL support, gRPC integration, and message queue adapters for Kafka and RabbitMQ.

    February 2026

    Release Notes

  • v0.8.0 — Data Layer

    Database connection pooling, Redis integration, and transaction support with automatic rollback.

    February 2026

    Release Notes

  • v0.7.0 — Enterprise Observability

    OpenTelemetry distributed tracing, structured health check endpoints, and GraphQL support.

    January 2026

    Release Notes

  • v0.6.0 — Smart Middleware

    Intelligent caching with TTL, adaptive rate limiting based on system load, DTO validation, and circuit breaker.

    December 2025

    Release Notes

  • v0.5.0 — Security & DI

    Dependency injection, composable RBAC guards, Prometheus metrics, and OpenAPI generation.

    October 2025

    Release Notes

  • v0.4.0 — Auth & Sessions

    JWT authentication, token-bucket rate limiting, secure cookie sessions, security headers, and cluster mode.

    August 2025

    Release Notes

  • v0.3.0 — Real-time

    WebSocket support, Server-Sent Events, multipart form handling, and modular blueprints.

    June 2025

    Release Notes

Support Policy

Version Status Support Until
1.2.x Active Current
1.1.x Maintenance December 2026
1.0.x Maintenance October 2026
0.10.x Security Only August 2026
< 0.10 End of Life —

Version policy

Cello follows Semantic Versioning. Starting with v1.0.0, the public API is stable — no breaking changes until v2.0. Maintenance releases receive bug fixes. Security Only releases receive critical security patches only.

Upgrading

# Upgrade to the latest stable release
pip install --upgrade cello-framework

# Pin to a specific version
pip install cello-framework==1.3.0

cello-framework>=1.3.0,<2.0.0

[project]
dependencies = [
    "cello-framework>=1.3.0,<2.0.0",
]

Read the migration guide before upgrading

Breaking changes are documented in the Migration Guide. Always review it before bumping a minor version.

Additional Resources

  • Full Changelog

    Every commit, bug fix, and improvement in one place.

    Changelog

  • Migration Guide

    Step-by-step instructions for upgrading between versions.

    Migration Guide

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