Launch HN: Coasty (YC S26) – An API for computer-use agents
8 hours ago
- #machine management
- #task automation
- #API reference
- Coasty API enables autonomous task execution on managed machines, allowing users to run tasks, compose workflows, and access low-level prediction primitives for direct control when needed.
- Authentication requires an API key sent via X-API-Key or Bearer headers, with test keys available for non-billing development and CI; keys must be kept secure and server-side.
- Task runs involve creating runs with machine_id and task parameters, polling or using webhooks/SSE streams for status updates, and handling human takeovers via resume endpoints when agents pause.
- BYOK (Bring Your Own Key) allows using custom Anthropic or OpenAI models by storing keys or sending headers, with per-role overrides and billing through provider accounts while Coasty platform charges apply unchanged.
- Workflows compose multiple runs into versioned JSON DSL programs with branching and loops, enabling task chaining, condition gating, and result passing; runs can be started from saved or inline definitions.
- Machines are managed VMs provisioned via API with lifecycle controls (start, stop, terminate), TTL-based auto-destroy, and runtime billing per minute; connection secrets and control endpoints allow direct interaction.
- Low-level primitives include predict for stateless steps, sessions for stateful trajectories, grounding for coordinate detection, and parse for converting pyautogui code to structured actions.
- Error handling provides JSON envelopes with codes and request IDs, with retry logic for specific cases; billing is per call from a prepaid wallet, with refunds confirmed via headers on failures.
- Pricing details per-step charges, machine runtime rates, and surcharges for features like grounding or high-resolution screens; troubleshooting tips address common mistakes like key misconfiguration.