Agent skill · software engineering · jeremylongshore
runway-local-dev-loop
Build and test a Runway integration locally with recorded contracts, deterministic task states, and an opt-in paid canary. Use when shortening iteration without duplicate spend. Trigger with: "develop Runway locally", "mock Runway tasks", "Runway dev loop".
Why this skill is useful
Provides specific implementation patterns and error handling for the Runway AI video generation platform that the AI wouldn't reliably generate on its own.
What it needs
Requires curl, npm, pip installed locally. Requires runwayml account access. About 3k tokens when loaded. Last updated 2026-08-07. 2,604 stars on the source repository.
What this skill does
Runway Offline-First Development Loop Overview Make routine development deterministic and non-billable. The local loop should model Runway's asynchronous protocol accurately, while a separately authorized canary detects provider drift without turning every test run into paid generation. Prerequisites A local service boundary that can replace the Runway client Redacted fixtures for create, task states, HTTP errors, and task failures A disabled-by-default credential path for an approved canary Instructions Step 1: Map the seam Use Read and Grep to locate direct SDK calls, task persistence, output download code, retries, and cancellation. Introduce one provider interface if application code currently imports the SDK everywhere. Step 2: Model the state machine Create fixtures for PENDING, THROTTLED, RUNNING, SUCCEEDED, FAILED, and CANCELLED. Make only SUCCEEDED include output; make failed fixtures include a machine-readable failure code. Step 3: Separate clocks and network Inject polling time, jitter, timeout, and HTTP transport. Tests should advance a fake clock and never wait five real seconds or contact Runway. Step 4: Protect against duplicate work Persist an internal operation ID and provider task ID. Simulate a lost response after task creation and prove recovery reads the saved task rather than issuing another paid request. Step 5: Test media boundaries Use tiny synthetic files and fixtures for public URL, data URI, and runway:// input. Model auto-crop review, upload expiry, output expiry, and owned-storage copy without retaining real signed URLs. Step 6: Run an opt-in canary Require an explicit environment switch, safe prompt, model schema check, credit ceiling, and named approver. Keep CI and ordinary local commands on the fake provider. Authentication Fixtures contain no usable secrets. The optional canary reads RUNWAYMLAPISECRET only in the server process, uses the reviewed version header, and refuses to run when the opt-in approval variables are incomplete. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills jeremylongshore/runway-local-dev-loop