# Component Catalog Source: https://docs.settlemint.com/docs/architecture/components Map DALP component layers from entry surfaces to infrastructure services, asset contracts, token features, and optional capabilities, with the owner, control scope, exclusions, and next detail page for each layer. DALP organises components by asset lifecycle job. This catalog owns the cross-layer map for architecture review. Each linked detail page owns the mechanics for one layer. Architecture reviewers, security reviewers, operators, and integrators locate the surface that controls a decision, evidence trail, or handoff here. Platform surfaces accept operator and integration requests. Infrastructure services execute and observe those requests. Asset contracts enforce token rules on EVM networks. Token features extend each asset, and capabilities add focused workflows around the asset. ## How to read the component model [#how-to-read-the-component-model] Start with the workflow or review question, then move to the layer that controls the relevant decision or evidence. The component pages explain architecture scope before task guides, API references, or deployment material. The model is layered for review, not for deployment ownership. DALP owns the platform surfaces, infrastructure services, contract model, token-feature attach points, and capability workflows listed here. Operators, issuers, custody providers, RPC providers, feed sources, payment providers, and market venues own the off-platform policies, provider configurations, operating procedures, and legal obligations named in the external-scope column. A regulated workflow usually crosses several layers. Issuing or transferring an asset may start in the Asset Console or Unified API, pass through authorization and durable execution, request custody signing, call SMART Protocol contracts, apply token features, and emit events for audit and read models. ## Choose the right detail page [#choose-the-right-detail-page] | Review question | Start with | Why | | ------------------------------------------------------------------------- | -------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------ | | How do operators or external systems enter DALP? | [Platform layer](/docs/architecture/components/platform) | Explains the Asset Console, Unified API, and System Factory as the request entry surfaces. | | Which backend services execute and observe a workflow? | [Infrastructure layer](/docs/architecture/components/infrastructure) | Covers durable execution, signing, contract calls, indexing, EVM connectivity, and feed inputs. | | Which on-chain token model enforces asset rules? | [Asset contracts](/docs/architecture/components/asset-contracts) | Covers DALPAsset, ERC-3643 integration, instrument configuration, roles, and legacy specialised types. | | Which per-asset extension adds fees, yield, maturity, voting, or history? | [Token features](/docs/architecture/components/token-features) | Maps runtime-pluggable extensions that attach to DALPAsset tokens. | | Which addon owns a workflow outside the base token contract? | [Capabilities](/docs/architecture/components/capabilities) | Maps airdrop, vault, XvP settlement, token sale, and issuer-signed scalar feed workflows. | ## Component layers [#component-layers] | Layer | What DALP covers | Owner and external scope | Detail page | | --------------- | --------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------- | | Platform | User and integration entry through the Asset Console, Unified API, and System Factory. | DALP owns the entry surfaces and shared backend controls. Operators own user access policy, external callers, and operating decisions. | [Platform layer](/docs/architecture/components/platform) | | Infrastructure | Workflow execution, transaction preparation, signing routes, contract runtime, chain indexing, RPC access, and feed resolution. | DALP owns the orchestration and integration points. Operators and providers own custody policy, RPC selection, feed-source contracts, response procedures, and deployment sizing. | [Infrastructure layer](/docs/architecture/components/infrastructure) | | Asset contracts | EVM asset tokens, compliance hooks, identity links, factory deployment, token roles, and on-chain events. | DALP owns the contract model and documented role behavior. Issuers own legal instrument terms, custody policy, and investor onboarding outside DALP. | [Asset contracts](/docs/architecture/components/asset-contracts) | | Token features | Asset-level extensions for fees, voting power, historical balances, permit approvals, maturity redemption, conversion, and yield. | DALP owns the feature contracts and attach points. Issuers own economic terms, tax treatment, accounting treatment, and external valuation evidence. | [Token features](/docs/architecture/components/token-features) | | Capabilities | Optional addons for distribution, treasury control, settlement, token sales, and signed market data. | DALP owns the documented addon workflows. Operators and providers own venue operations, payment rails, legal settlement process, and provider procedures. | [Capabilities](/docs/architecture/components/capabilities) | ## Component inventory [#component-inventory] ### Platform [#platform] User-facing interfaces that operators and integrators interact with directly. | Component | Responsibility | | ----------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------- | | [Asset Console](/docs/architecture/components/platform/asset-console) | Web interface for asset lifecycle management, compliance workflows, portfolio views, and distribution management. | | [Unified API](/docs/architecture/components/platform/unified-api) | OpenAPI-documented programmatic access to platform operations. | | [System Factory](/docs/architecture/components/platform/system-factory) | Organisation system creation and token factory scoping for asset isolation. | ### Infrastructure [#infrastructure] Backend services that power workflow execution, signing, chain connectivity, indexing, and external value inputs. | Component | Responsibility | | --------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------- | | [Execution Engine](/docs/architecture/components/infrastructure/execution-engine) | Reliable workflow orchestration with persistent state and exactly-once semantics. | | [Key Guardian](/docs/architecture/components/infrastructure/key-guardian) | Secure cryptographic key storage with HSM and cloud KMS integration. | | [Transaction Signer](/docs/architecture/components/infrastructure/transaction-signer) | Transaction preparation, gas estimation, nonce management, and signing. | | [Contract Runtime](/docs/architecture/components/infrastructure/contract-runtime) | Smart contract interaction, ABI encoding, and call routing. | | [Chain Indexer](/docs/architecture/data-availability/chain-indexer) | Blockchain event processing, data translation, and queryable state projection. | | [Chain Gateway](/docs/architecture/components/infrastructure/chain-gateway) | Multi-network connectivity with failover and load balancing. | | [EVM RPC Node](/docs/architecture/components/infrastructure/evm-rpc-node) | Blockchain network access for transaction submission and state queries. | | [Feeds System](/docs/architecture/components/infrastructure/feeds-system) | Trusted market data feeds for pricing, NAV calculations, and reference data. | | [Account abstraction](/docs/architecture/components/infrastructure/account-abstraction) | ERC-4337 smart-account execution paths when account abstraction is configured. | ### Asset contracts [#asset-contracts] The foundational contract primitive, DALPAsset, and specialised legacy types for existing deployments. | Component | Responsibility | | ---------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------- | | [Asset Contracts](/docs/architecture/components/asset-contracts) | DALPAsset, ERC-3643 integration, legacy-equivalent presets, specialised token types, deployment architecture, and role-based administration. | ### Token features [#token-features] Runtime-pluggable extensions that add fees, governance, lifecycle, approvals, history, conversion, and yield to DALPAsset tokens. | Component | Responsibility | | -------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ | | [Token Features](/docs/architecture/components/token-features) | Runtime-pluggable features for DALPAsset: fees, voting power, historical balances, permit approvals, maturity redemption, conversion, and yield. | ### Capabilities [#capabilities] Optional system addons that extend asset workflows without changing the base asset contract. | Component | Responsibility | | ------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------- | | [Airdrop](/docs/architecture/components/capabilities/airdrop) | Token distribution across push, merkle-drop, and vesting strategies. | | [Vault](/docs/architecture/components/capabilities/vault) | Multi-signature treasury management with configurable approval thresholds. | | [XvP Settlement](/docs/architecture/components/capabilities/xvp-settlement) | Atomic cross-party settlement with delivery-versus-payment mechanics. | | [Token Sale (DAIO)](/docs/architecture/components/capabilities/token-sale) | Digital Asset Initial Offering with configurable sale parameters. | | [Issuer-Signed Scalar Feed](/docs/architecture/components/capabilities/issuer-signed-scalar-feed) | Issuer-signed scalar values for market data and reference-value workflows. | ## Related [#related] * [Overview](/docs/architecture/overview) for architecture principles and quality attributes. * [Key flows](/docs/architecture/flows) for cross-component operation sequences. * [Integrations](/docs/architecture/integrations) for provider responsibilities and external system handoffs. * [Security](/docs/architecture/security) for trust boundaries and controls mapping. * [Deployment topology](/docs/architecture/overview/deployment-topology) for runtime zones and network responsibilities.