STF's VitorIA finds at least 247 similar appeals for Tema 1.261

AI system

System: VitorIA (STF), textual-similarity clustering tool that groups appeals raising similar legal questions; in development in 2022 and operational in 2023 per the STF
Model: Not assessed
Release: Not assessed
Application developer: Supremo Tribunal Federal (STF); the STF's 28 Sep 2026 item names no external developer and does not link VitorIA to the court's earlier Victor project
Role: Not assessed
Configuration: Not assessed
Inputs and outputs: Not assessed
Autonomy: Not assessed
Workflow: Electronic appeals in machine-readable text for VitorIA to compare. The STF's 2021 Victor item documents same-day OCR of all electronic appeals since December 2020. No cited source ties that layer to VitorIA, so the dependency is inferred. Textual-similarity clustering by VitorIA proposing groups of similar appeals. Human screening teams and ministers deciding whether to open a theme and how to rule.
Human oversight: Not assessed
Relation to AI: The STF says its function precedes judgment: “identificar grupos de casos parecidos, que depois passam pela análise das equipes responsáveis e, quando necessário, dos ministros.” The identification of at least 247 similar appeals is attributed to VitorIA by the court itself. The court adds that finding them “não determinou o resultado”. The theme decision was made by the Plenary. Developer and deployer are the same public body (STF). The STF news items are the court documenting its own tool. No cited source names an external developer or links VitorIA to the court's earlier Victor project (STF with UnB). The STF said in August 2021 that Victor's classifier was not yet in production.
AI contribution: The STF says its function precedes judgment: “identificar grupos de casos parecidos, que depois passam pela análise das equipes responsáveis e, quando necessário, dos ministros.” The identification of at least 247 similar appeals is attributed to VitorIA by the court itself. The court adds that finding them “não determinou o resultado”. The theme decision was made by the Plenary. Developer and deployer are the same public body (STF). The STF news items are the court documenting its own tool. No cited source names an external developer or links VitorIA to the court's earlier Victor project (STF with UnB). The STF said in August 2021 that Victor's classifier was not yet in production.

Benefits

Outcome identifiers: Not assessed
Benefit: identified at least 247 similar appeals in the controversy behind Tema 1.261
Category: Improved Knowledge Discovery
Status: Not assessed
Beneficiary groups: People. Organizations. Society.
Beneficiaries: Not assessed
Reach: Not assessed
Distribution and access: Not assessed
Duration: Not assessed
Expected?: Yes
Costs and harms: Not assessed

Measurement

Studies: Not assessed
Study design: Not assessed
Measurement: Not assessed
Setting and sample: Not assessed
Measures: identified at least 247 similar appeals in the controversy behind Tema 1.261
Comparison: Not assessed
Results: identified at least 247 similar appeals in the controversy behind Tema 1.261
Additional value from AI: Not assessed
Limitations: Not assessed
Denominators: Not assessed
Materials for replication: Not assessed

Money

Kind of value: Not assessed
Amount: Not assessed
Currency and prices: Not assessed
Period and unit: Not assessed
Realization: Not assessed
Recipients and payers: Not assessed
Gross or net: Not assessed
Included costs: Not assessed
Comparison: Not assessed
Method: Not assessed
Return and payback: Not assessed

People and places

Participants: Developer: Supremo Tribunal Federal (STF); the STF's 28 Sep 2026 item names no external developer and does not link VitorIA to the court's earlier Victor project. Operator: Supremo Tribunal Federal (STF).
Jurisdictions: Benefit: Brasília, Brazil. Developer: Brazil. Operator: Brazil.
Ownership and control: Not assessed
Dependencies: Not assessed
Cross-border connections: Not assessed
Geopolitical implications: Not assessed

Follow-up

Conditions for replication: Appeals filed electronically with machine-readable text. A procedural device (repercussão geral themes) that lets one decision govern many appeals. Staff capacity to review proposed clusters.
Replication attempts: 2 follow-up entries. Benefit recurred: 2.
Later findings: 28 September 2026. The STF's September 2026 statement reports the tool still in use after Tema 1.261, credited with 19 themes in 2024 and 11 in 2025 after four in 2023 (years only), while saying the figures do not allow computing accuracy or time saved.
Availability: Not assessed
Institutional decision: Not assessed
Grounds: Not assessed
Action and result: Not assessed
Success criterion: Not assessed

Evidence

Source numbers: AIBD-0085-source-0001–0003
Citations: Numbered references below.
Language: Not assessed
Source relationships: Developer
Original evidence: Not assessed
Access and versions: Not assessed
Supported findings: Not assessed
Evidence links: Not assessed
Evidence strength: Not assessed
Missing evidence: Not assessed

Grades

Assessed benefits: People. Organizations. Society.
Depth: People: Not assessed. Organizations: 2. Society: 1.
Reasons: People: No individual beneficiary or per-party outcome is documented. The STF says its figures do not refer to decisions taken with AI help and do not allow calculating time saved. Organizations: Material to the court's screening work: in one controversy VitorIA identified at least 247 appeals with similar legal questions. The STF describes this as the technology taking part in organizing and identifying patterns in its case flow. The STF does not quantify time saved. Society: Small at system scale. One theme among the 34 the STF credits to VitorIA for 2023–2025.
Observed or intended: Not assessed
Rubric: Not assessed
Assessor and date: Not assessed
Alternative assessments: Not assessed
Fill: The makers' claim

Entry details

Kind

Not assessed

Related entries

Brazilian court AI that reads case petitions (Galileu), the same kind of tool as STF's VitorIA, was targeted by hidden prompt injection, harming judicial integrity and defendants.

Field

Courts: appellate case management. Supreme court general-repercussion screening.

Purpose

Identify clusters of textually similar appeals so the court can treat them jointly or open new general-repercussion themes

Dates

Date basis unassessed: 2023 (precision unassessed). Updated: 21 October 2026.

Stage

Not assessed

Version

SHA-256: d4e33ebdaef4…

References

Other identifiers: AI Incident Database: 1497.
Category mappings: Not assessed
Brief: Not assessed
Revisions: 6 revisions. Latest: 21 October 2026.

Sources

Court document Developer

Supremo Tribunal Federal (2023). Repercussão Geral, Tema 1261, leading case ARE 1441934 (Relator: Ministro Presidente); decision of 22 Aug 2023, trânsito em julgado 23 Sep 2023.
Press release Developer

Supremo Tribunal Federal (2026). Inteligência artificial ajuda STF a identificar processos que discutem questões semelhantes. STF news, 28 Sep 2026.
Press release Developer

Supremo Tribunal Federal (2021). Projeto Victor avança em pesquisa e desenvolvimento para identificação dos temas de repercussão geral. STF news, 19 Aug 2021. Background on the court's earlier Victor project (STF with Universidade de Brasília); the item does not mention VitorIA.