Arquivo Eleitoral
A searchable archive of Portuguese parties' electoral promises, linked to original sources.
Arquivo Eleitoral is a database of electoral promises made by Portuguese political parties since 2002: searchable, comparable, and linked directly to the original electoral programmes and source material. Its tagline captures the idea behind the project: what they promised, and where the proof is.
I designed and built it end to end, from product strategy and interface design to the data pipeline and full-stack implementation.
Problem
Although many political parties keep their old campaign programmes online, access ultimately depends on the parties themselves. Websites are redesigned, content is reorganised, and documents can disappear without notice.
Arquivo.pt, a Portuguese web archive, exists to preserve websites and documents that would otherwise be lost. It captures snapshots of the web over time, allowing older versions of pages and files to remain accessible even after they have been changed or removed.
A good example to illustrate this problem is Iniciativa Liberal's 2019 legislative election programme, the election in which the party first won representation in parliament. The programme is no longer available on the party's website, and the only way to access it online today is through the copy preserved by Arquivo.pt.
In many cases, the material exists in the archive, preserved exactly as it appeared at the time, but finding it is difficult. Documents are scattered across archived URLs, buried inside PDFs, and impossible to search or compare in any meaningful way.
Answering a simple question such as "what did PS, PSD and Bloco de Esquerda promise about housing between 2015 and 2022?" often means hours of manual research. There was no place where journalists, researchers, or citizens could quickly find those promises alongside the original sources.
Solution
Arquivo Eleitoral extracts and indexes promises from Portuguese electoral programmes, making them searchable by theme, party, and election.
Every promise links directly to its source. Where an archived copy exists, users are taken to the preserved version on Arquivo.pt, complete with its timestamp. For more recent elections, where programmes may still be available on party websites and have not yet been archived, the promise links to the original document instead. The goal is the same in both cases: allow users to verify the source for themselves rather than relying on summaries or interpretations.
Comparison became the central feature of the product. Users can explore how different parties approached the same issue across multiple elections, viewing promises side by side with the original source material. What started as a search tool became a way to analyse political positions over time.
Building the archive
Collecting more than two decades of electoral material by hand would be unrealistic, so the archive is built through an automated extraction pipeline.
The process runs in two stages. Claude first extracts potential promises from source documents and assigns a confidence score. A second pass evaluates whether each promise is specific, attributable, and verifiable. Only the ambiguous cases require manual review.
The platform is also explicit about gaps in the historical record. If a programme was never captured by the archive, that absence is documented rather than hidden.
Under the hood, the project uses FastAPI and SQLite with native full-text search, a Next.js and Tailwind frontend, and Claude-powered extraction and validation workflows. It is deployed on Render and Vercel.
Results
Arquivo Eleitoral currently contains 11,872 promises spanning nine political parties and every Portuguese legislative election from 2002 to 2025.
As far as I have been able to determine, it is the first project to combine electoral promises, source verification, and cross-party comparison in a single searchable platform.
The project serves three audiences:
- Journalists comparing party positions across multiple elections.
- Citizens checking whether a promise was made and reading the original source.
- Researchers who need structured political data without spending months collecting it themselves.
Status and future plans
Arquivo Eleitoral is live and received an Honorable Mention at the Prémio Arquivo.pt 2026.
Future plans include refining and fine-tuning the extraction pipeline, manually reviewing every promise in the archive, and expanding coverage to all Portuguese elections since 1975 to provide a clearer view of the country's democratic history. Longer term, I would also like to add information about whether promises led to concrete outcomes, supported by links to the Diário da República and other primary sources so users can verify the evidence themselves.