cities-skylines1-agent-skill

name	cities-skylines1-agent-skill
description	Operate Cities: Skylines 1 through the Skylines Agent Bridge mod and localhost API. Use when Codex needs to build, inspect, repair, resume, save, or continue a CS1 city using focused API calls rather than screenshot recognition, including road connectivity, service infrastructure, zoning, facilities, problem icons, and save verification.

Cities: Skylines 1 Agent Skill

Use this skill to control a running Cities: Skylines 1 city through the local Skylines Agent Bridge API.

Core Rules

• Prefer API state over image recognition.
• Resume and repair existing saves by default. Start fresh only when explicitly requested.
• Use small, separated commands: inspect, bulldoze, build, place, move, zone, simulate, save.
• Save after meaningful city changes and verify the .crp file exists.
• Commit repository changes after each coherent code/docs task when working inside this repository.

Local Setup

The bridge listens on:

http://127.0.0.1:32123

Build and install the mod:

powershell -NoProfile -ExecutionPolicy Bypass -File .\scripts\build.ps1

Resume the latest save:

powershell -NoProfile -ExecutionPolicy Bypass -File .\scripts\start-resume.ps1

Start a new map only when the user asks:

powershell -NoProfile -ExecutionPolicy Bypass -File .\scripts\start-new-map.ps1

Inspection Loop

Use these before acting:

Invoke-RestMethod http://127.0.0.1:32123/health
Invoke-RestMethod http://127.0.0.1:32123/state/summary
Invoke-RestMethod "http://127.0.0.1:32123/state/chirps?limit=50"
Invoke-RestMethod http://127.0.0.1:32123/state/zones
Invoke-RestMethod "http://127.0.0.1:32123/state/problems?limit=200"
Invoke-RestMethod "http://127.0.0.1:32123/state/economy"
Invoke-RestMethod "http://127.0.0.1:32123/state/road-anomalies?limit=500&nearMissDistance=18&shortSegmentLength=32&includeDeadEnds=false"
Invoke-RestMethod "http://127.0.0.1:32123/state/building-anomalies?limit=200"
Invoke-RestMethod "http://127.0.0.1:32123/state/zone-anomalies?limit=200&includeUnzonedHoles=true"
Invoke-RestMethod "http://127.0.0.1:32123/state/facilities?limit=500"
Invoke-RestMethod "http://127.0.0.1:32123/state/growables?limit=500"
Invoke-RestMethod "http://127.0.0.1:32123/state/networks?limit=1000&service=Road"

Use includeMapObjects=true on /state/facilities only when raw helper objects such as pipe junctions are needed.

Command Pattern

Use separate commands so the repair remains auditable.

Delete a bad segment:

$body = @{ entityType = "netSegment"; id = 19023; keepNodes = $false } | ConvertTo-Json
Invoke-RestMethod -Method Post -Uri http://127.0.0.1:32123/commands/bulldoze -Body $body -ContentType "application/json"

Build a network segment:

$body = @{
  roadPrefab = "Basic Road"
  start = @{ x = 400; z = 300 }
  end = @{ x = 423.614; z = 554.945 }
  name = "Agent Highway Link"
} | ConvertTo-Json -Depth 5
Invoke-RestMethod -Method Post -Uri http://127.0.0.1:32123/commands/build-network -Body $body -ContentType "application/json"

Place or move a building:

$body = @{ buildingPrefab = "Water Tower"; position = @{ x = 120; z = -220 }; angleDegrees = 0 } | ConvertTo-Json -Depth 5
Invoke-RestMethod -Method Post -Uri http://127.0.0.1:32123/commands/place-building -Body $body -ContentType "application/json"

Paint zones:

$body = @{ zone = "ResidentialLow"; preserveOccupied = $true; center = @{ x = 240; z = -40 }; radius = 70 } | ConvertTo-Json -Depth 5
Invoke-RestMethod -Method Post -Uri http://127.0.0.1:32123/commands/set-zone -Body $body -ContentType "application/json"

Run simulation:

$body = @{ paused = $false; speed = 3 } | ConvertTo-Json
Invoke-RestMethod -Method Post -Uri http://127.0.0.1:32123/commands/set-simulation-speed -Body $body -ContentType "application/json"

Lower taxes when /state/problems reports TaxesTooHigh:

$body = @{ service = "Commercial"; rate = 9 } | ConvertTo-Json
Invoke-RestMethod -Method Post -Uri http://127.0.0.1:32123/commands/set-tax-rate -Body $body -ContentType "application/json"

Save and verify:

powershell -NoProfile -ExecutionPolicy Bypass -File .\scripts\save-city.ps1 -Name AgentAutoSave-clean
Invoke-RestMethod http://127.0.0.1:32123/state/saves

Known Gotchas

• CS1 network crossings are not intersections unless a real node is created. If a pipe or road visually crosses another segment but does not connect, bulldoze and rebuild split segments with a shared endpoint.
• Heating service buildings may create an actual connection helper offset from the building center. Query /state/facilities?service=Water&includeMapObjects=true when diagnosing heating pipe issues.
• Roads that look connected to highways can still have separate nodes. Use /state/road-anomalies and rebuild with endpoints close enough to reuse the existing road nodes.
• Do not treat all dead ends as errors. Use bounded checks or includeDeadEnds=false unless the user asks to remove cul-de-sacs/stubs.
• Use /state/zone-anomalies when zone colors look mottled or circular paint left residential/commercial/industrial/office cells mixed in the same block.
• /commands/set-zone defaults to preserveOccupied=true; check /state/growables first and keep that flag enabled unless the user explicitly wants to repaint developed blocks.
• If screenshots show blue/green/yellow mottling across a whole city block, use /state/zone-anomalies and repair with /commands/repair-zone-clusters using preferGrowableZone=true.