Lambda Cloud vs Vast.ai

Lambda Cloud

H100 SXM at $3.99 and B200 at $6.69 an hour with per-minute billing. No scale to zero, autoscaling or endpoints; an idle VM bills until terminated.

Vast.ai

API keys can be limited by permission category and by resource ID, the REST API has a public OpenAPI 3.1 file, and the CLI ships weekly with a skill file for coding agents. Machines belong to independent hosts, prices move with the market, rate-limit thresholds are unpublished, and there is no SLA or free tier.

Lambda Cloud

1. Call GET /instance-types first and read regions_with_capacity_available before trying to launch
2. Space launch calls 12 seconds apart; a sixth in a minute returns 429 with global/rate-limited
3. Branch on the error code, not the message or suggestion, which Lambda says may change
4. List instances before retrying a failed launch, since there's no idempotency key and a retry can start a second machine
5. Terminate the instance in a finally block; billing runs by the minute until you do

Vast.ai

1. Create a scoped key with vastai create api-key --permissions for the agent. A default key has full account access, billing and key management included
2. Pass --raw on every CLI command for JSON output, and -y on vastai destroy instance, which otherwise waits for a confirmation prompt
3. Register an SSH key with vastai create ssh-key before creating an instance, or the host is unreachable
4. Destroy instances when finished. A stopped instance still bills storage, and a zero balance without a saved card leads to deletion
5. Back off on HTTP 429 yourself when calling REST directly. The CLI retries 429 three times from 0.15 seconds
6. Filter searches with verified=true or the Secure Cloud option for sensitive data, and set a dph_total price cap