How Idempotency Keys Prevent Duplicate Transactions in Financial APIs

·1 views

Financial backend systems face a risk of duplicate transactions when clients retry failed network requests, potentially posting the same operation twice. To counter this, developers can design idempotent APIs that use unique idempotency keys to track and deduplicate requests. The approach combines Redis for atomic in-progress locking and cached response storage with PostgreSQL for enforcing key uniqueness at the database schema level. A FastAPI-based implementation demonstrates how concurrent duplicate requests are rejected with a 409 Conflict response, while completed transactions return a cached result. The pattern also supports multithreaded testing via pytest and httpx to validate concurrency safety.

Read the full story at DEV Community

This is an AI-generated summary. ShortSingh links to the original source for the complete article.

Discussion (0)

Google Reveals $94.1B SpaceX Stake, Equivalent to About 6% Ownership

Google has publicly disclosed that it holds approximately $94.1 billion worth of SpaceX stock, representing roughly a 6% stake in the private space company. The disclosure sheds light on the scale of Google's investment in Elon Musk's aerospace venture. SpaceX remains one of the most valuable private companies in the world, and such a stake underscores significant institutional confidence in its growth. The revelation highlights the deepening financial ties between major tech firms and the commercial space industry.

0 comments Read more at Hacker News

ProgrammingDEV Community ·

AI Coding Tools Are Closing Up — Forking Is How Developers Fight Back

For decades, developers freely customized their tools by modifying or forking them, but the rise of AI-powered coding assistants has quietly eroded that freedom. Leading agent harnesses like Claude Code and Google's successor to Gemini CLI are vendor-controlled products rather than open, forkable repositories. While many of these tools offer plugin ecosystems and extension APIs, the author argues those represent permissions granted by vendors, not true developer autonomy. The falling cost of agentic coding now makes forking large, complex AI tools far more practical than it once was, reviving an old but powerful option. The essay urges developers to reclaim customization by forking tools outright rather than waiting for vendors to expose the right extension points.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

Could AI-Generated Videos Distort How Future Generations Understand Physics?

AI video generation can now produce visually convincing scenes that violate real-world physics, such as objects defying gravity or moving without inertia. Humans develop intuitive physics — an internal model of how the world behaves — through direct observation and interaction from early childhood, not from equations. Cognitive scientists warn that the brain uses predictive processing, constantly matching visual input against this internal model, which is shaped heavily by experience. Unlike video games, which apply consistent fictional physics, AI-generated videos may present unstable and contradictory physical rules across different clips. Researchers are now questioning whether prolonged exposure to such inconsistent synthetic content could gradually reshape how future generations perceive and reason about the physical world.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

Hugging Face Highlights 10 AI Papers on Self-Improving Agents and LLM Research

Hugging Face's trending papers list for July 26, 2026 featured ten notable AI research works spanning diverse topics. Among the top-upvoted entries was AREX, a recursively self-improving research agent that evaluates its own outputs and refines its query strategies across multiple iterations. Another highlighted paper, SLAI T-Rex, demonstrated the feasibility of full-parameter post-training of large models like DeepSeek-V4 on Huawei's Ascend hardware, offering an alternative to NVIDIA-dependent infrastructure. A third paper addressed a curriculum-alignment problem in K-12 education by building a knowledge graph tied to structured learning progressions. The roundup reflects growing research interest in agentic AI systems, hardware-diverse training pipelines, and domain-specific LLM applications.

0 comments Read more at DEV Community