Weld
Weld is a programmable data-infrastructure platform for moving and transforming data. It runs near real-time ELT/ETL pipelines from 300+ prebuilt connectors, log-based Change Data Capture (CDC), SQL-based data transformations with lineage and version history, and Reverse ETL to activate modeled data back into operational tools. The Weld Connect REST API and a hosted Model Context Protocol (MCP) server let developers and AI agents create connections, run and monitor ELT syncs, build and publish transforms, and orchestrate pipelines programmatically. Weld is a Copenhagen-based company backed by a16z and other leading investors.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles Weld the way a machine reads it — 18 machine-readable artifacts across 13 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Weld scores 51.8/100 (developing), with a separate agent-readiness read of 69/100 (agent native). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile Weld
Each block below is one kind of artifact we hold for Weld. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 13
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
Weld Connection Bridge API
The Connection Bridge API from Weld — 1 operation(s) for connection bridge.
Weld Connections API
The Connections API from Weld — 3 operation(s) for connections.
Weld Custom Reports API
The Custom Reports API from Weld — 1 operation(s) for custom reports.
Weld ELT Stream Runs API
The ELT Stream Runs API from Weld — 2 operation(s) for elt stream runs.
Weld ELT Streams API
The ELT Streams API from Weld — 5 operation(s) for elt streams.
Weld ELT Syncs API
The ELT Syncs API from Weld — 8 operation(s) for elt syncs.
Weld Integrations API
The Integrations API from Weld — 1 operation(s) for integrations.
Weld Orchestration Runs API
The Orchestration Runs API from Weld — 2 operation(s) for orchestration runs.
Weld Orchestrations API
The Orchestrations API from Weld — 3 operation(s) for orchestrations.
Weld Reverse ETL Failed Records API
The Reverse ETL Failed Records API from Weld — 4 operation(s) for reverse etl failed records.
Weld Reverse ETL Sync Runs API
The Reverse ETL Sync Runs API from Weld — 2 operation(s) for reverse etl sync runs.
Weld Reverse ETL Syncs API
The Reverse ETL Syncs API from Weld — 9 operation(s) for reverse etl syncs.
Weld Transforms API
The Transforms API from Weld — 11 operation(s) for transforms.
Scroll within the panel for all 13 ·
MCP Servers 1
Model Context Protocol servers expose these APIs directly to AI agents. We profile them because agent-native access is the fastest-growing way this provider's capabilities actually get used.
Model Context Protocol servers that expose these APIs to AI agents.
weld-mcp.yml
MCP SERVERSecurity Posture 3
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for Weld — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 3
Portal, sign-up, and the first successful call
Documentation 2
Reference material describing how the API behaves
Agent Surfaces 5
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 5
Pagination, idempotency, versioning, errors, and events
Access & Security 4
Authentication, authorization, and security posture
Operate 3
Status, limits, changes, and where to get help
Commercial 3
Pricing, plans, and the legal terms of use
Company 2
The organization behind the API
Other 1
Properties that don't map to a standard resource type
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