RCSB PDB · Rate Limits

Pdb Rate Limits

RCSB PDB APIs implement rate limiting to ensure fair access across all users. Static file downloads (https://files.wwpdb.org, rsync://rsync.rcsb.org) are not rate-limited. All other API services return HTTP 429 when a client exceeds the allowed request rate. RCSB PDB recommends starting at a few requests per second and adjusting based on observed 429 responses. Exact numeric ceilings are not published; clients should implement polite harvesting patterns.

Pdb Rate Limits is the machine-readable rate-limit profile for RCSB PDB on the APIs.io network, conforming to the API Commons Rate Limits specification.

It captures 7 rate-limit definitions, measuring requests-per-second and unlimited.

The profile also includes 3 backoff/retry policies defined and response codes documented for throttled.

Tagged areas include Structural Biology, Bioinformatics, Life Sciences, Open Data, and Rate Limiting.

7 Limits Throttle: 429
Structural BiologyBioinformaticsLife SciencesOpen DataRate Limiting

Limits

Data API Default client
requests-per-second
10
Recommended starting rate; actual ceiling undisclosed. Applies to https://data.rcsb.org REST and GraphQL endpoints.
Search API Default client
requests-per-second
10
Recommended starting rate; actual ceiling undisclosed. Applies to https://search.rcsb.org/rcsbsearch/v2/query.
ModelServer API Default client
requests-per-second
10
Recommended starting rate; actual ceiling undisclosed.
VolumeServer API Default client
requests-per-second
10
Recommended starting rate; actual ceiling undisclosed.
Sequence Coordinates API Default client
requests-per-second
10
Recommended starting rate; actual ceiling undisclosed.
Structure Alignment API Default client
requests-per-second
10
Asynchronous job submission; recommended starting rate undisclosed.
File Downloads (Unrestricted) client
unlimited
-1
Bulk downloads via https://files.wwpdb.org or rsync://rsync.rcsb.org are not rate-limited; polite harvesting is expected.

Policies

Backoff Strategy
Implement exponential backoff with jitter. Honor the Retry-After header when present in HTTP 429 responses before retrying.
Polite Harvesting
For large-scale or batch workloads spread requests over time and prefer off-peak hours. Consider rsync for full archive replication rather than scraping the HTTP API.
Fair Use
All APIs are freely shared infrastructure. Sustained high-volume usage that degrades service for other users may result in temporary blocks beyond documented rate limits.

Sources