# MQLFix > MT4 and MT5 technical service enquiries, recovery assessment, program repairs, migration and custom development. Default language: English. Chinese: https://mqlfix.top/zh/ Human assessment: https://mqlfix.top/assessment/ Public facts: https://mqlfix.top/data/site.json Read-only API: https://mqlfix.top/openapi.json ## Important facts - The first enquiry is free; project scope and payments are agreed privately. - Reference recovery prices: indicator USD 80–200; EA USD 200–500. These are not universal fixed quotes. - AISTIM technical cases are attributed; examples are not represented as completed projects. - No public endpoint accepts code, executes decompilation, charges a payment or guarantees a trading result. - Contact: https://t.me/alonginchina, power.yang.china@gmail.com. ## Pages - [MT4 & MT5 Decompiler, Recovery & Development](https://mqlfix.top/): EX4 to MQ4 and EX5 to MQ5 recovery assessment, program repairs, MT4 to MT5 conversion and custom development. Clear scope, published AISTIM cases and a free first enquiry. - [MT4 & MT5 technical services](https://mqlfix.top/services/): Choose source recovery, program repairs, migration, custom EAs and indicators or diagnostics. - [EX4 to MQ4 recovery](https://mqlfix.top/services/ex4-to-mq4/): MT4 indicators and Expert Advisors. Start with the original file and a clear delivery request. - [EX5 to MQ5 recovery](https://mqlfix.top/services/ex5-to-mq5/): MT5 source-recovery assessment with a defined scope, dependency list and verification process. - [License & expiry issues](https://mqlfix.top/services/license-and-expiry/): Account binding, expiry messages and activation problems: define the issue and the permitted repair. - [MT4 to MT5 conversion](https://mqlfix.top/services/mt4-to-mt5/): Port MQL4 source to MQL5 and verify the behavior that matters to your workflow. - [Custom EAs & indicators](https://mqlfix.top/services/custom-development/): Turn an explicit trading or display specification into software you can test and maintain. - [Diagnostics & behavior checks](https://mqlfix.top/services/diagnostics-testing/): Investigate errors, indicator differences and EA behavior using repeatable evidence. - [Case studies & project examples](https://mqlfix.top/cases/): Inspect a published AISTIM recovery case and existing tools, with evidence boundaries and clearly labeled example briefs. - [Apex Scanner Elite — AISTIM public case](https://mqlfix.top/cases/apex-scanner-elite/): Original and delivered MT4 build comparison, 75 inputs and 9 dropdown options reported in the AISTIM public case. - [MT4 & MT5 practical guides](https://mqlfix.top/guides/): Prepare better briefs, understand files, plan migration and check program deliveries. - [EX4, EX5, MQ4 and MQ5: what to send](https://mqlfix.top/guides/ex4-ex5-mq4-mq5/): Identify your program, source files and dependencies before requesting a quote. - [A practical MT4 to MT5 migration checklist](https://mqlfix.top/guides/mt4-to-mt5-checklist/): Separate code changes from the behavior you need to preserve. - [What to check before approving a verification build](https://mqlfix.top/guides/verification-before-balance/): A repeatable acceptance process for source recovery and repair work. - [Your EA is not trading: prepare a useful diagnostic brief](https://mqlfix.top/guides/ea-not-trading/): Collect the setup and evidence that make a problem reproducible. - [How to brief an indicator repainting check](https://mqlfix.top/guides/indicator-repainting/): Separate historical appearance from observations made as bars arrive. - [Write an EA brief a developer can actually implement](https://mqlfix.top/guides/write-an-ea-brief/): Replace vague strategy descriptions with rules and worked examples. - [Free MT4 & MT5 tools](https://mqlfix.top/tools/): Local source-file checks, position-risk arithmetic, drawdown recovery and points-to-price calculations. - [Position-risk calculator](https://mqlfix.top/tools/risk-calculator/): Calculate volume from your own contract inputs. - [Drawdown recovery calculator](https://mqlfix.top/tools/drawdown-calculator/): See the return needed to recover a drawdown. - [Points & price distance](https://mqlfix.top/tools/points-calculator/): Convert points using the symbol point size you supply. - [Local source-file check](https://mqlfix.top/tools/source-check/): Check file types and migration signals without uploading code. - [How assessment, quotation & delivery work](https://mqlfix.top/how-it-works/): Understand file handoff, pricing references, deposits and verification before final delivery. - [Request a free MT4 / MT5 assessment](https://mqlfix.top/assessment/): Send your platform, file types and requested outcome. Enquiries go to both published contact inboxes. - [About MQLFix & contact](https://mqlfix.top/about/): Contact MQLFix for MT4 / MT5 assessments. See our AISTIM technical references and enquiry channels. - [Privacy & enquiry data](https://mqlfix.top/privacy/): How the enquiry form and local tools handle your information. - [Service scope & payment terms](https://mqlfix.top/terms/): Confirm file-specific deliverables, price, timing, payment and acceptance before work begins. - [MQLFix information for AI agents & crawlers](https://mqlfix.top/ai/): Read-only service facts, structured content, Markdown and public API documentation.