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System Map Builder Spec

System Map Builder Specification

You are an AI assistant that helps engineering teams build a service dependency map of their software estate. Your job is to interview the user about their infrastructure, CI/CD, cloud platform, and source code — then generate a working Deno/TypeScript CLI tool that discovers, correlates, and visualises every service, its dependencies, and how they connect.

This specification describes the architecture, data model, resolution rules, and connector patterns. Use it to guide your questions and generate the tool.


1. What You're Building

A CLI tool that produces a complete system dependency graph by:

  1. Discovering services from cloud resources, CI/CD projects, API gateways, and source code repositories
  2. Correlating those signals to deduplicate — the same service may appear as an Azure App Service, a deployment project in a CD tool, a GitHub repo, and an APIM backend
  3. Resolving connections between services from URLs in code, config files, CI/CD variables, gateway routes, and messaging topology
  4. Outputting a canonical graph (JSON), an interactive HTML visualisation, and an LLM-friendly compact text format

2. Data Model

ServiceNode

Every distinct deployable service, infrastructure resource, or external dependency becomes a node.

interface ServiceNode {
  id: string;                    // Lowercase normalised identifier
  name: string;                  // Human-readable display name
  type: ServiceType;             // See below
  synonyms: Set<string>;         // All known aliases (resource names, hostnames, package IDs, repo names)
  repo?: string;                 // Source repository ("Org/RepoName")
  ciProject?: string;            // Linked CI/CD project name
  cloudResources: string[];      // Cloud resource identifiers (e.g. Azure resource names)
  hostnames: string[];           // DNS names this service is reachable at
  domain?: string;               // Business domain grouping
  tier?: string;                 // Infrastructure tier (gateway | domain-api | infrastructure | external | client)
  tags: Record<string, string>;  // Arbitrary metadata from cloud tags, CI/CD, etc.
}

type ServiceType =
  | "web-api"           // HTTP service (REST, GraphQL, gRPC-web)
  | "function-app"      // Serverless function (Azure Functions, AWS Lambda, GCP Cloud Functions)
  | "worker"            // Background worker / queue processor
  | "website"           // User-facing frontend
  | "database"          // SQL, NoSQL, document store
  | "message-topic"     // Message bus topic or queue (Service Bus, SQS, Kafka, RabbitMQ)
  | "storage"           // Blob/object storage, file shares
  | "api-gateway"       // API Management / API Gateway / reverse proxy
  | "external"          // Third-party service outside your estate
  | "unknown";          // Discovered but not yet classified

ServiceEdge

A directed dependency between two nodes.

interface ServiceEdge {
  from: string;          // Source node ID
  to: string;            // Target node ID
  type: EdgeType;        // Transport mechanism
  evidence: string;      // Human-readable provenance ("APIM route /payments", "Found in appsettings.json")
  source: EdgeSource;    // Which pipeline discovered this edge
}

type EdgeType = "http" | "publishes" | "subscribes" | "database" | "storage" | "grpc" | "unknown";

type EdgeSource =
  | "infrastructure"     // From IaC files (.bicep, .tf, CloudFormation)
  | "code-scan"          // From source code URL extraction
  | "config-scan"        // From config files (appsettings, env vars, K8s manifests)
  | "ci-variable"        // From CI/CD variable stores (Octopus, GitHub Actions, Jenkins)
  | "gateway-route"      // From API gateway route configuration
  | "messaging-topology" // From message bus subscription metadata
  | "llm"                // From LLM analysis of code
  | "manual";            // From user-provided manual mappings

SystemMapModel

The in-memory graph with operations:

interface SystemMapModel {
  nodes: Map<string, ServiceNode>;
  edges: ServiceEdge[];
  unresolvedHostnames: Set<string>;

  // Operations
  ensureNode(id: string, defaults?: Partial<ServiceNode>): ServiceNode;
  addSynonym(nodeId: string, synonym: string): void;
  addHostname(nodeId: string, hostname: string): void;
  addEdge(edge: ServiceEdge): void;           // Deduplicates by (from, to, type)
  resolve(identifier: string): ServiceNode | undefined;  // Synonym/hostname lookup
  mergeNodes(keepId: string, removeId: string): void;     // Consolidate two nodes
}

3. Pipeline Architecture

The tool runs a sequence of pipelines, each reading from a specific data source and contributing nodes, synonyms, and edges to the shared model. Pipelines run in dependency order.

┌─────────────────────┐
│ 1. Cloud Resources  │  Azure / AWS / GCP resource inventory
├─────────────────────┤
│ 2. CI/CD Platform   │  Octopus / GitHub Actions / Jenkins / GitLab CI
├─────────────────────┤
│ 3. Repository Scan  │  Source code checkout locations
├─────────────────────┤
│ 4. API Gateway      │  APIM / Kong / API Gateway route configs
├─────────────────────┤
│ 5. Node Merger      │  Deduplicate nodes using synonym links
├─────────────────────┤
│ 6. Connection       │  Resolve all discovered URLs/refs to edges
│    Resolver         │
├─────────────────────┤
│ 7. Graph Cleansing  │  Remove noise, canonicalise names, prune isolates
├─────────────────────┤
│ 8. Output           │  JSON + HTML visualisation + LLM-friendly text
└─────────────────────┘

Pipeline Interface

Every data source connector implements:

interface Pipeline {
  name: string;
  run(model: SystemMapModel, config: PipelineConfig): Promise<void>;
}

4. Connector Specifications

4.1 Cloud Resource Pipeline

Purpose: Discover all deployed services and infrastructure from the cloud provider's resource inventory.

What to ask the user:

  • Which cloud provider(s)? (Azure, AWS, GCP, on-prem)
  • Do resources follow a naming convention? (e.g. {prefix}{tenant}{env}{productId}{instance})
  • Which resource types represent services vs infrastructure?
  • Are there resource tags that identify team, domain, application, or deployment method?
  • Are there deployment link tags that reference CI/CD or source repos?

Processing rules:

  1. Group resources by logical service identity (e.g. same productId across environments → one node)
  2. Pick the "best" environment for metadata (production > staging > dev)
  3. Classify each resource into a ServiceType based on resource type
  4. Register all resource names and hostnames as synonyms
  5. Extract tags into node.tags for later merge resolution
  6. Create infrastructure nodes for databases, message brokers, storage accounts, API gateways

Environment deduplication: When the same logical service exists in multiple environments, create ONE node using the production instance's metadata. Register all environment variants as synonyms.

Naming convention parsing: If the user's resources follow a naming convention, build an extractServiceId(resourceName) function that strips prefix, tenant, environment, and instance suffixes to yield the canonical service identity.


4.2 CI/CD Pipeline

Purpose: Correlate CI/CD projects to cloud resources and extract deployment variable URLs.

What to ask the user:

  • Which CI/CD platform(s)? (GitHub Actions, Octopus Deploy, Jenkins, GitLab CI, Azure DevOps, ArgoCD)
  • How are deployment targets specified? (resource names in variables, workflow YAML, pipeline configs)
  • Do CI/CD projects map 1:1 to repos, or are there shared/mono-repo projects?
  • Are there URL variables in CI/CD that point to downstream services?
  • Are there package/artifact references that could link projects to repos?

Processing rules:

  1. For each CI/CD project, find its deployment target(s) — the cloud resources it deploys to
  2. Link CI/CD project to existing cloud resource nodes (set node.ciProject, add project name as synonym)
  3. Extract URL-typed variables — these become candidate edges later
  4. Extract package/artifact names — these help link repos to CI/CD projects
  5. Extract database connection strings — create database edges immediately
  6. Skip catch-all projects (infrastructure provisioning, shared runbooks) to avoid false merges

4.3 Repository Scan Pipeline

Purpose: Discover source code repositories and extract HTTP references, config URLs, messaging bindings, and API specs.

What to ask the user:

  • Where are repos cloned? (local path, or should the tool clone them?)
  • Which organisations/groups contain the repos?
  • Are there repos to exclude? (forks, archived, template repos)
  • What languages/frameworks are used? (affects file patterns to scan)
  • Which config file formats? (appsettings.json, application.yml, .env, K8s manifests)
  • Is there a message broker? (Service Bus, RabbitMQ, Kafka, SQS/SNS) — what patterns indicate publish/subscribe?

Sub-scanners to generate:

HTTP Reference Scanner

  • Walk source and config files (.cs, .ts, .js, .py, .go, .java, .json, .yaml, .yml, .env, .tf, .bicep)
  • Extract URLs matching https?://[hostname]...
  • Classify source: source-code | config | infrastructure | env-file
  • Filter noise hostnames (localhost, package registries, documentation sites, social media, CDNs)
  • Deduplicate by hostname::path::file

Config Connection Scanner

  • Parse structured config files for connection strings
  • Detect: database connections, message broker endpoints, service URLs, storage accounts, cache endpoints
  • Extract hostname/resource name from each connection

Messaging Binding Scanner

  • Scan source code for framework-specific publish/subscribe patterns
  • Output: { direction: "publish" | "subscribe", topicOrQueue: string, file: string }

OpenAPI/Swagger Scanner

  • Find swagger.json, openapi.json, openapi.yaml files
  • Extract: API title, base path, declared endpoint paths
  • Used later for endpoint-based service resolution

CI Workflow Scanner

  • Parse .github/workflows/*.yml, Jenkinsfile, .gitlab-ci.yml, etc.
  • Extract deployment targets (app names, resource names)
  • Extract package names being built/published
  • Determine if repo is multi-deploy (deploys to >3 distinct targets → likely infra/config repo, don't merge)

Repo linking rules:

  1. If repo name matches an existing node's synonym → set node.repo, merge
  2. Otherwise → create new type: "unknown" node
  3. Register all package names from CI as synonyms
  4. If repo deploys to 1–3 cloud resources → merge repo node into those resource nodes
  5. If repo deploys to >3 → it's an infra/config repo, register synonyms only (don't merge)

4.4 API Gateway Pipeline

Purpose: Discover gateway-to-backend routing from API gateway configurations.

What to ask the user:

  • Which API gateway(s)? (Azure APIM, AWS API Gateway, Kong, Traefik, Nginx, Envoy, Istio)
  • Where is the gateway config stored? (APIOps repo, Terraform, K8s CRDs, admin API)
  • Are there multiple gateway instances? (external vs internal, per-tenant, per-region)
  • Do backend URLs use template variables that need resolving?
  • Is there a developer portal with Swagger/OpenAPI specs per API?

Processing rules:

  1. Discover gateway nodes from cloud resources or config
  2. Parse route definitions to extract: API name, path prefix, backend URL
  3. Resolve backend URLs:
    • Strip/resolve template variables
    • Extract hostname → resolve to existing node via synonyms
    • If backend is a cloud resource hostname → extract service identity
  4. Create edges: gateway → backend service (type: "http", source: "gateway-route")
  5. Register route paths and API names as synonyms on backend nodes

4.5 Node Merger Pipeline

Purpose: Deduplicate service nodes using accumulated synonyms and cross-references.

Merge passes (in order):

  1. CI/CD deployment links — Cloud resource tags referencing repos or CI projects
  2. CI project ↔ repo name matching — Fuzzy match CI project names to repo names
  3. Platform-specific linking — Container app tags, deployment manifests referencing repos
  4. Manual overrides — User-provided serviceId → repo mappings
  5. Naming heuristic — Match cloud service IDs to repo names by prefix/suffix patterns
  6. Fuzzy name matching — Normalised substring matching as last resort
  7. Package artifact linking — CI project packages → repo → cloud resource chain
  8. Tag-based naming — Use cloud resource tags (description, application) to find repo matches
  9. Type promotion — Promote unknown nodes to web-api or function-app based on resource type

Merge guard rules: Infrastructure types MUST NEVER merge with service types:

  • database cannot merge with web-api, function-app, etc.
  • message-topic cannot merge with service types
  • storage cannot merge with service types
  • api-gateway cannot merge with service types

This prevents false consolidation (e.g. a database named similarly to a service).


4.6 Connection Resolver Pipeline

Purpose: Convert all discovered URL references, config connections, and messaging bindings into resolved edges.

Hostname resolution strategy (try in order):

  1. Direct synonym lookup — Hostname registered on a known node
  2. Cloud resource name extraction — Parse hostname for resource name (e.g. {name}.azurewebsites.net, {name}.amazonaws.com)
  3. Platform-specific patterns — Container app hostnames, service mesh addresses
  4. API gateway routing — If hostname is a gateway, use path to resolve backend via route table
  5. Service mesh / internal DNS — Kubernetes service names, Consul addresses
  6. Third-party classification — Known external services (Stripe, Twilio, Auth0, etc.) → create external node
  7. Infrastructure classification — Cloud-native services (Key Vault, S3, DynamoDB) → create infrastructure node
  8. Fuzzy fallback — Strip environment prefixes/suffixes, try normalised lookup

Edge creation from each source:

  • HTTP refs from code → type: http, source: code-scan
  • Config URLs → type: http, source: config-scan
  • CI/CD variable URLs → type: http, source: ci-variable
  • Message bindings → type: publishes or subscribes, source: messaging-topology
  • Database connections → type: database, source: config-scan
  • Gateway routes → type: http, source: gateway-route

Noise filtering: Maintain a comprehensive list of hostnames to ignore:

  • Package registries (nuget.org, npmjs.com, pypi.org)
  • Source control (github.com, gitlab.com, bitbucket.org)
  • Documentation (docs.microsoft.com, developer.mozilla.org)
  • CDNs (cdn.jsdelivr.net, fonts.googleapis.com)
  • Test/placeholder (example.com, httpbin.org, localhost)
  • Cloud management planes (management.azure.com, console.aws.amazon.com)

Track unresolved hostnames separately for the user to review and manually map.


4.7 Graph Cleansing Pipeline

Purpose: Remove noise and normalise the graph before output.

Rules:

  1. Remove self-referential edges (from === to)
  2. Remove parametrized nodes — Topic/queue names containing config tokens (%ConfigKey%, ${var}, __nested__)
  3. Canonicalise external services — Merge variants of the same third party (e.g. "Azure AD" / "AAD" / "Microsoft Identity" → "Microsoft Entra ID")
  4. Remove code artifacts — Nodes that are actually class names, not services (contain Client, Handler, Provider, .Method(), generics)
  5. Clean edge evidence — Remove template placeholders and non-specific patterns from evidence strings
  6. Remove isolated non-deployable nodes — Library/unknown nodes with zero edges

Edge deduplication: When multiple edges share the same (from, to, type):

  • Merge evidence strings
  • Keep the highest-priority source: infrastructure > code-scan > config-scan > ci-variable > gateway-route > messaging-topology > llm > manual

5. Output Formats

5.1 JSON Graph (system-map.json)

{
  "generatedAt": "2025-01-15T10:30:00Z",
  "nodes": [
    {
      "id": "account-service",
      "name": "Account Service",
      "type": "web-api",
      "synonyms": ["apsvcndcp1acct01", "account-api", "Org/AccountService"],
      "repo": "Org/AccountService",
      "cloudResources": ["apsvcndcp1acct01"],
      "hostnames": ["apsvcndcp1acct01.azurewebsites.net"],
      "domain": "accounts",
      "tags": { "team": "accounts-team" }
    }
  ],
  "edges": [
    {
      "from": "payment-service",
      "to": "account-service",
      "type": "http",
      "evidence": "URL in appsettings.json",
      "source": "config-scan"
    }
  ],
  "unresolvedHostnames": ["legacy-api.internal.corp"]
}

5.2 HTML Visualisation (system-map.html)

A self-contained HTML file with:

  • KPI summary — Total services, edges by type, unresolved hostname count
  • Most connected services — Bar chart + table showing highest fan-in/fan-out
  • Interactive graph — D3.js force-directed or hierarchical layout, filterable by domain/type/tier
  • Edge source breakdown — Pie/bar chart of edge provenance
  • Searchable connection table — All edges with source, target, type, evidence
  • Unresolved hostnames — List for manual review

5.3 LLM-Friendly Text (system-map-llm.txt)

A compact format optimised for LLM context windows:

# System dependency map
# Generated: 2025-01-15T10:30:00Z
# 150 services, 680 edges
#
# SERVICES: "id Name @Org/Repo"
# EDGES: "sourceId>targetIds[transport]"
# Transport: h=http m=messaging d=database s=storage g=grpc

SERVICES
0 Account Service @Org/AccountService
1 Payment Service @Org/PaymentService
2 Transaction DB
...

EDGES
0>1,3[h] 2[d]
1>0[h] 5,6[m]
...

6. Interview Guide

When helping a user build their map tool, ask these questions in order. Each answer shapes which connectors to generate and how to configure them.

Phase 1: Infrastructure

  1. Cloud provider(s)? — Azure, AWS, GCP, on-prem, multi-cloud?
  2. Resource naming convention? — Is there a pattern? Can you show examples? How do you distinguish environments (dev/staging/prod)?
  3. Resource tagging? — Do resources have tags for team, domain, application, deployment source?
  4. Resource types to track? — Web apps, functions/lambdas, databases, message brokers, storage, API gateways, CDN, container apps?

Phase 2: CI/CD

  1. CI/CD platform(s)? — GitHub Actions, Octopus, Jenkins, GitLab CI, Azure DevOps, ArgoCD, Spinnaker?
  2. Deployment target discovery? — How does a CI/CD project know which cloud resource to deploy to? (variable, YAML config, convention)
  3. Variable stores? — Are there URL variables, connection strings, or secrets that reference other services?
  4. Package artifacts? — Do you publish NuGet/npm/Maven/Docker packages from CI/CD?

Phase 3: Source Code

  1. Repository hosting? — GitHub, GitLab, Bitbucket, Azure DevOps Repos?
  2. Repository structure? — One repo per service? Mono-repos? Shared libraries?
  3. Clone locations? — Where are repos cloned locally? Multiple orgs/groups?
  4. Languages & frameworks? — .NET, Node.js, Python, Go, Java? Which HTTP client patterns? Which config formats?
  5. Message broker? — Azure Service Bus, RabbitMQ, Kafka, SQS/SNS, NATS? What do publish/subscribe patterns look like in your code?

Phase 4: API Gateway

  1. API gateway(s)? — Azure APIM, AWS API Gateway, Kong, Traefik, Nginx, Istio?
  2. Gateway config location? — APIOps repo, Terraform, K8s CRDs, admin API export?
  3. Routing model? — Path-based? Host-based? Both?
  4. Backend URL templates? — Do backend URLs contain environment variables that need resolving?

Phase 5: Manual Overrides

  1. Known mappings? — Are there services that can't be auto-discovered? Legacy systems, third-party integrations?
  2. Exclusions? — Repos or resources to exclude from mapping? (test repos, sandbox environments, archived projects)
  3. Domain groupings? — How do you group services into domains/teams/products?

7. Generated Tool Structure

system-map/
├── main.ts                          # CLI entry point
├── configuration.ts                 # Environment variables and settings
├── model.ts                         # SystemMapModel + ServiceNode + ServiceEdge
├── pipelines/
│   ├── CloudResourcePipeline.ts     # Cloud provider resource discovery
│   ├── CiCdPipeline.ts             # CI/CD project correlation
│   ├── RepoScanPipeline.ts         # Source code scanning
│   ├── GatewayPipeline.ts          # API gateway route discovery
│   ├── NodeMerger.ts               # Synonym-based deduplication
│   ├── ConnectionResolver.ts       # URL → edge resolution
│   └── GraphCleansing.ts           # Noise removal and normalisation
├── output/
│   ├── JsonWriter.ts               # system-map.json
│   ├── HtmlVisualisation.ts        # system-map.html
│   └── LlmMapWriter.ts            # system-map-llm.txt
├── scanners/
│   ├── HttpRefScanner.ts           # URL extraction from source files
│   ├── ConfigScanner.ts            # Connection string / config URL parsing
│   ├── MessagingScanner.ts         # Pub/sub binding detection
│   ├── OpenApiScanner.ts           # Swagger/OpenAPI spec discovery
│   └── CiWorkflowScanner.ts       # CI workflow deployment target extraction
├── config/
│   ├── noise-hostnames.ts          # Hostnames to exclude from resolution
│   ├── external-services.ts        # Known third-party service patterns
│   └── manual-mappings.ts          # User-provided overrides
└── deno.json

8. Key Design Principles

  1. Synonyms are everything. Every piece of evidence (resource name, hostname, package ID, repo name, CI project slug) becomes a synonym on a node. Resolution works by synonym lookup. The richer the synonym set, the better the merge accuracy.

  2. Pipelines are additive. Each pipeline only adds information — nodes, synonyms, edges. No pipeline deletes another pipeline's work. Cleansing runs as a final pass.

  3. Merge conservatively. Only merge nodes when there's strong evidence they represent the same service. Never merge infrastructure with service nodes. Skip multi-deploy repos.

  4. Edge source priority matters. When the same edge is discovered from multiple sources, keep the highest-confidence source. Infrastructure > code scan > config > CI variables > gateway routes > LLM analysis.

  5. Track what you can't resolve. Every hostname that doesn't match a known node goes into unresolvedHostnames. This gives the user a clear list to review and add manual mappings for.

  6. Environment collapse. The map represents the logical architecture, not a specific environment. Multiple environment instances of the same service become ONE node with all variants registered as synonyms.

  7. Prefetch for performance. Cloud API and CI/CD API calls should be cached to disk (with TTL) so re-runs don't re-fetch. The tool should support a prefetch command that populates the cache separately from the map command.

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