CP 2026 Call for Papers

Thirty Second Conference on Principles and Practice of Constraint Programming CP 2026 

                        July 20-23, 2026, Lisbon, Portugal

CP is the premier international event for presenting research in all aspects of computing with constraints, including, but not restricted to: theory, algorithms, environments, languages, models, systems, and applications. CP 2026 is the 32nd conference in this series and will be held in Lisbon, at ISCTE – Instituto Universitário de Lisboa (July 18-19 and July 24-25: workshops, July 20-23: main conference). This year, CP is part of the the Federated Logic Conference (FLoC) 2026.

The CP conference welcomes submissions that advance the state of the art for the underlying constraint-based technologies, as well as papers that explore the role of constraint programming within other disciplines, such as operations research, machine learning, computational sustainability, quantum computing, computational biology and (cyber)security.

Tracks and Primary Keywords

CP has lately had both a main technical track, an application track and a series of specialised tracks (e.g., machine learning, operations research, etc.) that authors could submit to and were mutually exclusive. This year, inspired by the previous CP conference, we will only have two tracks: technical and application where, as usual, the former focuses on the scientific contributions made “to” CP, while the latter focuses on scientific contributions made “with” CP. The application track is particularly interested in papers that demonstrate the effectiveness of CP in solving real-world problems, as well as those that offer generalisable insights on the challenges and benefits for both users and developers of applying CP to both academic and real-world problems.

Former specialised tracks are replaced by a set of optional primary keywords, which are in addition to the keywords requested from authors every year. Their purpose is to enable submissions to self-identify the area of focus of the CP paper, support the identification of suitable reviewers. Authors (resp. reviewers) will be able to select zero, one or more primary keywords to reflect best the thematic contributions of their CP paper (resp. reviewer expertise).

The primary keywords that can be used to qualify the particular focus of the CP research presented in the paper are:

Theory
Constraint Propagation
Filtering algorithms
Explanation & Inference
Solver
Search (Complete & Heuristic)
SAT
MaxSAT
Logic Programming
Modelling & Modelling Languages
Operations Research & Mathematical Optimisation
Machine Learning & Generative AI
Verification
Certification
Testing
Hardware
Quantum
Security & Parallelism
Model Counting
Decision Diagrams
Dynamic Programming
Symmetries
Dominance
Model/Instance Explainability

Important Dates

Submissions open: 01/02
Abstract registration: 28/02
Paper submission: 07/03
Author rebuttal: 09/04-12/04
Final notification: 30/04
Camera Ready: 07/05
Conference: 20/07-23/07

Dates are intended as 11pm Anywhere on Earth (AoE, also known as UTC-12).

Submission Instructions

The submission Web page for CP 2026 uses the HotCRP system. The change in the submission system has been made to facilitate integration within FLoC.

Papers should be submitted in the form of a PDF file following LIPIcs guidelines.

To open the conference more widely, two types of submissions are expected:

Full papers, that can use up to 15 pages (references and appendices excluded).
Short papers, that can use up to 8 pages (references and appendices excluded). Short papers cover early results or highly specific results that can be adequately reported in 8 pages. They must nonetheless respect the quality expectations of the conference. Both full and short papers should attract a wide audience and will be allocated time for presentation during the conference.

Appendices of up to 6 pages for full papers and up to 3 pages for short papers can be included and will not contribute towards the total page count provided they are clearly marked as an appendix. Supplemental material (for example, experimental results or code) may be referenced, but only if this is done without revealing the authors’ identities (for example, by using https://anonymous.4open.science) to fit our double-blind review process (see below). Papers should be self-contained and be comprehensible without reference to either appendices or supplemental material. Authors should not place elements essential to their paper in either appendices or supplemental material and indeed it will be left to the discretion of each reviewer whether they refer to this material or not.

To facilitate reviewing management, authors who intend to submit a paper to CP 2026 should submit an abstract with a maximum of 150 words, summarising the contribution of the paper and indicating the track and primary keywords by February 28, 2026. The paper submission must be completed by March 7, 2026.

All papers will go through a double-blind reviewing process, meaning that authors and reviewers are mutually anonymous. For this reason, submitted papers should not contain author names, affiliations, or links to identifying websites. References to the authors’ own papers should be cited in such a way so as to avoid revealing the authorship of the paper. Authors will also be able to submit a single rebuttal for each paper during the period.

Submissions exceeding the page limits, improperly formatted, with author names/affiliations/identifying-websites will be rejected without review. The existence of a technical report (e.g., an ArXiV report) corresponding to the submission before March 8, 2026, will not constitute grounds for rejecting the submission, provided that the technical report is not referenced in the submission. This allows authors to date their contribution if they wish.

Submitted papers must not appear in, be accepted for, or be under review for a journal or another peer-reviewed conference with archived conference proceedings at the paper submission deadline, that is at March 7. Submissions that have appeared at workshops or other meetings and have not been formally published or have appeared only in highly shortened form (e.g. abstracts) can be submitted as papers.

Each paper must be submitted to one track only (technical or application). When necessary, the Program Chair may move a submission to a more suitable track before reviewing starts.

Accepted papers will appear in conference proceedings published by LIPIcs, and follow the authors instructions guidelines. The proceedings will be available at the time of the conference.

Diversity Equity Inclusion (DEI) scholarship and other support

CP 2026 offers DEI scholarships to support individuals from underrepresented groups. These scholarships provide financial assistance to cover conference attendance costs, including registration fees, travel, and accommodation. Scholarship recipients have the option to be integrated into the Doctoral Program, where they will receive mentorship opportunities.

Eligibility for the DEI scholarship requires applicants to be pursuing or holding a PhD in constraint programming or related fields. Note that paper submission is not required to qualify for the scholarship. Applicants will be asked to provide a statement of eligibility, a motivation letter, and a short CV.

In addition to the scholarships, CP 2026 is willing to support attendees with childcare or accessibility needs on a best-effort basis; if you are interested, please get in touch early to discuss your needs. For more information, follow the DEI page and contact the DEI chairs.

Use of Generative AI

CP 2026 is adopting the AAAI policy regarding the use of Generative AI systems such as ChatGPT. Papers that include text generated from an AI system are prohibited unless the produced text is presented as a part of the paper’s experimental setup. This does not prohibit authors from using AI systems for editing or polishing author-written text.

CP 2026 also follows AAAI policy in considering that AI systems, including Generative Models such as Chat-GPT, BARD, or DALL-E, do not satisfy the criteria considered for paper authorship and, as such, these systems cannot be used as authors or as citable sources in papers published in CP. Authors assume full responsibility for the content of submitted work, including checking for plagiarism and the veracity of all text.

Inclusive Description of Research Contributions

Please consider making your research contribution description inclusive in nature. For example, consider using gender-neutral pronouns, using examples that are ethnicity/culture-rich, engaging users from diverse backgrounds if your research involves a survey, etc. To make the paper accessible to visually impaired and colour-blind readers, your paper should be still readable when printed in grey scale. To achieve this, most printing should be in black and white, and you should use patterns, symbols and textures to emphasise and contrast visual elements in graphs and figures.