Software Buyer France — Claude plugin
Buy custom software in France without surprises. Sourced price benchmarks, specification review, quote and contract review, vendor questions, offer comparison, hosting decision, legacy takeover.
What it does
Skill (invoke as /software-buyer-france:<name>) | You get |
|---|---|
estimate | A low / likely / high budget range with its sources, an effort table and a 5-year total cost including licences |
review-spec | A readiness score for your specification (cahier des charges), the decisions to take before pricing, testable rewrites of weak requirements, integration checks |
review-quote | A verdict, red flags ranked by severity, missing clauses with wording to request (FR/EN), price positioning |
vendor-questions | 12–20 questions adapted to your project and situation, each with the good answer and the red flag |
compare-offers | A like-for-like comparison: scope coverage, 5-year cost, risk and ownership, recommendation |
hosting-decision | Cloud, sovereign cloud, SaaS or on-premise (priced as a separate option), decided before pricing |
legacy-takeover | A takeover plan when the previous developer or agency is gone: secure, audit, stabilise, then evolve or migrate |
Skills also trigger on their own when you ask things like "is this quote fair?", "combien coûte une application mobile ?" or "what should I ask this agency?".
Price data (MCP server prix-logiciel)
The plugin connects to a read-only MCP server that serves:
- French public procurement contracts (DECP) already awarded for ERP, mobile apps, digital transformation / project management assistance, production management (GPAO/MES) and digital twins — about 480 qualified contracts, with medians and quartiles published only above minimum sample sizes (median ≥ 5 contracts, quartiles ≥ 12). Source: data.economie.gouv.fr, Etalab 2.0 licence. Building/engineering false positives (CPV 45 and 71) and republished modifications are removed.
- Verified private-market figures: surveys, day-rate barometers and published price grids, each with URL, quote and date of check. Figures that could not be verified at the source are excluded.
Tools: search_public_contracts, price_statistics, private_market_prices, daily_rates, position_quote, sources_and_method. All are read-only; no account is needed.
There is no reliable public dataset for AI projects yet: the tools say so rather than invent a number.
The method behind the checklists
The review grids encode a buyer-protective standard used in real French software contracts:
- Map before you quote — a paid framing phase beats a firm price on a vague scope.
- Fixed price means capped — nothing invoiced above the total without a signed amendment; days are the vendor's commitment, not a billing base.
- Everything in your name from day one — code repository, hosting, domain, store accounts; rights transferred as you pay.
- Acceptance by written report, with deadlines on both sides; warranty after acceptance.
- A clean exit — bounded termination cost, reversibility (code, documentation, data, accesses) within a stated delay.
- Decide hosting before pricing — on-premise is a separately priced option, never an afterthought.
- Third-party costs at dated list prices, never "0 €" when unknown.
Not legal advice: have high-stakes contracts reviewed by a lawyer.
Further reading (JAIKIN, in French)
- How we frame and price custom software — Méthodologie · Développement logiciel sur mesure
- Custom software vs SaaS — Build or buy
- Mobile app budgets — Prix d'une application mobile
- Taking over an existing system — Reprise de SI legacy
- ERP projects — ERP sur mesure · Migration ERP PME
Install
/plugin marketplace add JAIKIN-SASU/claude-plugin-software-buyer
/plugin install software-buyer-france@jaikin
Once listed in the community marketplace: /plugin marketplace add anthropics/claude-plugins-community then /plugin install software-buyer-france@claude-community.
Privacy
See PRIVACY.md. The MCP server stores nothing about your conversations; the documents you review are read by Claude locally and never sent to the server.
Maintainer
Built and maintained by JAIKIN, Strasbourg (France). Issues and pull requests welcome.
Français
Acheter un logiciel sur mesure en France sans mauvaise surprise. Repères de prix sourcés, relecture de cahier des charges, de devis et de contrat, questions à poser au prestataire, comparaison d'offres, choix de l'hébergement, reprise d'un existant.
Skill (invoquer /software-buyer-france:<name>) | Ce que vous obtenez |
|---|---|
estimate | Une fourchette basse / probable / haute avec ses sources, le détail de l'effort et le coût complet sur 5 ans, licences comprises |
review-spec | La maturité de votre cahier des charges, les décisions à prendre avant tout chiffrage, les exigences réécrites pour être testables |
review-quote | Un verdict, les signaux d'alerte classés par gravité, les clauses manquantes avec leur formulation, le positionnement du prix |
vendor-questions | Les questions à poser au prestataire, avec la bonne réponse attendue et le signal d'alerte |
compare-offers | Une comparaison à périmètre égal : couverture, coût sur 5 ans, risque, propriété, recommandation |
hosting-decision | Cloud, cloud souverain, SaaS ou sur site (option chiffrée à part), tranché avant le chiffrage |
legacy-takeover | Un plan de reprise quand le développeur ou l'agence précédente a disparu : sécuriser, auditer, stabiliser, puis faire évoluer ou migrer |
Données de prix : marchés publics attribués (DECP, licence Etalab 2.0) pour l'ERP, les applications mobiles, la transformation numérique et l'AMOA, la GPAO/MES et le jumeau numérique ; chiffres du marché privé vérifiés à la source, avec URL et date.
La méthode : cartographier avant de chiffrer ; un forfait est plafonné ; tout est au nom du client dès le premier jour ; recette par procès-verbal ; sortie bornée et réversibilité ; hébergement tranché avant le chiffrage (le sur site est une option chiffrée à part) ; coûts tiers au tarif public daté, jamais « 0 € ».
Ceci n'est pas un conseil juridique. Plugin conçu et maintenu par JAIKIN, Strasbourg.