API QUICK REFERENCE
Common Screeps APIs
Search Game, Creep, Room, Structure, Market, and PathFinder APIs, then continue to a matching guide or official documentation.
Open API quick reference →SCREEPS KNOWLEDGE BASE
Browse Screeps by system
Browse 81 published English guides through eight indexable system pillars. Newly published guides appear in the relevant system automatically.
01
Memory and Code Structure
State, modules, global cache, RawMemory, flags, and maintainable game-loop structure.
12 published guides · Open system page- GETTING STARTED · BEGINNER LESSON 1 OF 12What Is Screeps? A Programming Strategy Game8 min read · Beginner · Lesson
- GETTING STARTED · BEGINNER LESSON 3 OF 12Screeps Ticks and Game Loop: Why Your Code Runs Repeatedly8 min read · Beginner · Lesson
- FOUNDATION · PERSISTENT STATEScreeps Memory: Persistent State, Heap Cache, and Creep Data12 min read · Intermediate · Guide
- FOUNDATION · ENERGY PHASE HYSTERESISScreeps Working State: Switch Only at Empty and Full11 min read · Intermediate · Guide
- FOUNDATION · SAVED TARGET RESOLUTIONScreeps Game.getObjectById(): Resolve Saved Targets Safely12 min read · Intermediate · Guide
- MEMORY · DEAD-CREEP CLEANUPScreeps: Clean Dead Creep Memory Safely11 min read · Intermediate · Guide
02
Spawn and Creep Lifecycle
Body design, spawn return codes, role memory, renewal, recycling, and emergency recovery.
13 published guides · Open system page- GETTING STARTED · BEGINNER LESSON 6 OF 12Screeps Creep Body Parts: WORK, CARRY, and MOVE8 min read · Beginner · Lesson
- GETTING STARTED · BEGINNER LESSON 7 OF 12Screeps spawnCreep(): Create Your First Creep8 min read · Beginner · Lesson
- GETTING STARTED · BEGINNER LESSON 8 OF 12Screeps Creep Roles: Harvester, Upgrader, and Builder8 min read · Beginner · Lesson
- SPAWNING · RETURN-CODE DIAGNOSISScreeps spawnCreep() Errors: Diagnose Every Return Code12 min read · Intermediate · Debugging
- SPAWNING · BODY BUDGET POLICYScreeps Dynamic Creep Body: Minimum, Target, and Emergency Plans13 min read · Intermediate · Guide
- SPAWNING · COLLAPSE RECOVERY STATEScreeps Emergency Harvester Recovery: Track the Exact Spawn Request17 min read · Intermediate · Guide
03
Room Economy
Harvesting, hauling, storage, links, terminals, minerals, and stable energy flow.
10 published guides · Open system page- GETTING STARTED · BEGINNER LESSON 4 OF 12Screeps Harvest Energy: Your First Creep Script9 min read · Intermediate · Guide
- GETTING STARTED · BEGINNER LESSON 5 OF 12Screeps Energy Delivery: Creep to Spawn10 min read · Beginner · Lesson
- FOUNDATION · CONTAINER WITHDRAWALHow to Make a Screeps Creep Withdraw Energy from a Container11 min read · Intermediate · Guide
- RESOURCE RECOVERY · DROPPED ENERGYHow to Make a Screeps Creep Pick Up Dropped Energy14 min read · Intermediate · Guide
- LOGISTICS · STORAGE BUDGET AND EVENT IDENTITYScreeps Storage Energy: Reserve Budgets and Verify Transfers18 min read · Intermediate · Guide
- LOGISTICS · LINK ENERGY COORDINATIONScreeps Link transferEnergy(): Coordinate Capacity and Verify Events16 min read · Intermediate · Guide
04
Movement and Vision
moveTo(), fatigue, RoomPosition, PathFinder, routes, observers, and room visibility.
12 published guides · Open system page- GETTING STARTED · BEGINNER LESSON 2 OF 12Screeps First Room: Find the Editor and Console8 min read · Beginner · Lesson
- MOVEMENT · ACTION RANGE DEBUGGINGScreeps ERR_NOT_IN_RANGE: Use the Correct Action Range11 min read · Intermediate · Debugging
- MOVEMENT · MULTI-TICK PROGRESS DEBUGGINGScreeps moveTo() Returns OK but the Creep Stays Put13 min read · Intermediate · Debugging
- MOVEMENT · PATH SEARCH DEBUGGINGScreeps ERR_NO_PATH: Diagnose Range, Matrices, and Routes15 min read · Intermediate · Debugging
- MOVEMENT · FATIGUE AND BODY DESIGNHow to Calculate Screeps Creep Movement Speed16 min read · Intermediate · Guide
- MOVEMENT · ROOMPOSITION DISTANCEWhich Screeps RoomPosition Distance Method Should You Use?15 min read · Intermediate · Guide
05
Controllers and Expansion
Upgrading, downgrade recovery, reserving, claiming, safe mode, and remote control.
5 published guides · Open system page- GETTING STARTED · BEGINNER LESSON 9 OF 12Screeps upgradeController(): Build Your First Upgrader Loop10 min read · Beginner · Lesson
- CONTROLLER · SAFE MODE ACTIVATIONScreeps activateSafeMode(): Prevent Same-Tick Intent Overwrite17 min read · Advanced · Guide
- CONTROLLER · DOWNGRADE RECOVERYScreeps Controller Downgrade Recovery: Verify Emergency Upgrades15 min read · Intermediate · Guide
- CONTROLLER · RESERVE AND CLAIM IDENTITYScreeps reserveController() vs claimController(): Verify the Exact Mission22 min read · Intermediate · Guide
- CONTROLLER · FIXED UPGRADER DIAGNOSTICSWhy a Fixed Screeps Upgrader Is Not Upgrading20 min read · Intermediate · Guide
06
Construction and Defense
Construction sites, Creep combat, towers, walls, ramparts, repairs, and defensive priorities.
13 published guides · Open system page- BEGINNER · FIRST EXTENSIONHow to Build Your First Screeps Extension12 min read · Beginner · Lesson
- BEGINNER · BUILD AND REPAIRHow to Make a Screeps Creep Build and Repair Automatically14 min read · Beginner · Lesson
- API SAFETY · CONSTRUCTIONHow to Remove a Construction Site Safely in Screeps12 min read · Intermediate · Safety
- DEFENSE · TOWER ATTACK EVENTSScreeps Tower.attack(): Verify One Multi-Tower Volley15 min read · Advanced · Guide
- DEFENSE · TOWER HEAL PRIORITYScreeps Tower Healing: Injury Ratio, Missing Hits, and Range17 min read · Intermediate · Guide
- DEFENSE · TOWER REPAIR EVENTSScreeps Tower.repair(): Verify Exact Repair Events16 min read · Intermediate · Guide
07
Market and Advanced Resources
Orders, deals, terminals, labs, boosts, factories, power, and late-game resources.
9 published guides · Open system page- MARKET · ORDER CREATION IDENTITYScreeps createOrder(): Bind One Request to the New Order ID19 min read · Advanced · Guide
- MARKET · DEAL SETTLEMENT IDENTITYScreeps market.deal(): Reserve the Terminal and Verify Actual Amount21 min read · Advanced · Guide
- LOGISTICS · TERMINAL INTENT IDENTITYScreeps Terminal.send(): Prevent Intent Overwrite and Verify Actual Amount21 min read · Advanced · Guide
- RESOURCES · OWNED LAB REACTIONScreeps runReaction(): Verify One Owned Lab Reaction14 min read · Advanced · Guide
- RESOURCES · BOOST TARGET IDENTITYScreeps Lab boostCreep(): Requirements, Usage, and Return Codes14 min read · Advanced · Guide
- RESOURCES · FACTORY BATCH VERIFICATIONScreeps Factory.produce(): Verify One Production Batch15 min read · Advanced · Guide
08
Operations and Debugging
Return codes, CPU, bucket, event logs, notifications, diagnostics, and safe operations.
7 published guides · Open system page- BEGINNER · FIRST ROOM LOOPScreeps First Room Code: A Small Loop You Can Verify14 min read · Beginner · Lesson
- RUNTIME · CPU PROFILINGScreeps CPU Profiling: Measure Code with Game.cpu.getUsed()12 min read · Intermediate · Guide
- OBSERVABILITY · RATE-LIMITED NOTIFICATIONSScreeps Game.notify(): Send Rate-Limited Alerts Safely11 min read · Intermediate · Guide
- OBSERVABILITY · ROOM EVENT LOGScreeps Room.getEventLog(): Read Previous-Tick Events11 min read · Intermediate · Guide
- OBSERVABILITY · ROOM VISUAL DEBUGGINGScreeps RoomVisual: Transparent Fills, Labels, and Paths10 min read · Intermediate · Debugging
- OPERATIONS · ROOM ERROR ISOLATIONScreeps Room Error Isolation: Keep Other Rooms Running18 min read · Intermediate · Debugging
ERROR REFERENCE
Return codes
Use common Screeps return codes as the first branch in an action debugging process.
Open error codes →GLOSSARY
Core terminology
Review concise definitions for the objects, resources, limits, and runtime concepts used across Screeps.
Open the glossary →RECENTLY VERIFIED
Runtime evidence
See English guides whose shared source records explicitly contain Console testing or live multi-tick verification.
Browse verified guides →TOOLS
Calculate and diagnose before editing production code
Use the English body, room, Market, Controller, Lab, Spawn, hauling, and Tower tools without connecting a Screeps account.
Browse tools →