Clear DeepSeek's data terms with legal before the first production call, then pin model names, schedule bulk work off-peak, and design prompts for cache hits. Handle HTTP 429s, empty answers, and leaked tool-call markup before agents depend on the API. This checklist covers data terms, model names, scheduling, caching, limits, and output checks.
When you need this
- A prototype on the DeepSeek API is about to carry customer traffic.
- Finance wants the lowest price per task and engineering is weighing DeepSeek against other model APIs.
- Agents on the API end turns early or return empty answers.
Evaluation criteria
Clear the data terms
May this data be stored in China and used for training?
Look forDeepSeek's privacy policy states that it collects, processes, and stores personal data in the People's Republic of China and uses it to train its models; depending on where users live, the policy lists a right to opt out. The Open Platform terms are governed by PRC law, and DHS order 2026-01 bars US federal civilian agencies. Get a written legal decision that covers training use.
Pin model names
Which model answers each name you call?
Look fordeepseek-flash is served by DeepSeek-V4.1-Flash-1017, and the legacy deepseek-v4-flash names are still accepted but route to it. DeepSeek's September 10, 2026 notice routed deepseek-v4-pro to V4.1 Flash from September 14 while the pricing page still lists V4-Pro-0813, so test which model answers and watch the news page.
Schedule bulk work off-peak
Which jobs can wait for half-price hours?
Look forPeak hours are 01:00 to 04:00 and 06:00 to 10:00 UTC on weekdays, excluding Chinese public holidays; every other hour is half price. Queue evaluations, backfills, and batch summaries for off-peak windows.
Design for cache hits
How much of your input is billed at the cache-hit price?
Look forContext caching on disk is on by default. Keep system prompts and long context stable at the start of each request, and track cache-hit tokens per response. Cache hits cost US$0.006 per million tokens on Flash at peak against US$0.30 for a miss, and practitioners report 99% hit rates on long tasks.
Handle limits
What happens past the concurrency limit?
Look forEach account allows 2,500 concurrent deepseek-flash requests and 500 for deepseek-v4-pro across all keys, and returns HTTP 429 above that. Back off and retry, pass a user_id per end user if you have a raised quota, and ask DeepSeek for more capacity, which costs nothing extra.
Check outputs in agent loops
What does your agent do with a bad response?
Look forRetry a stop finish with empty content, since one practitioner saw 13 of 45 replays end that way with the answer in reasoning_content. Strip internal tool-call markup from content when a request omits tools, and treat a one-sentence reply without a tool call as a failed turn.
Questions to ask vendors
- Has legal approved data storage in China and training use, and does the training opt-out apply where our users live?
- Which model answers each model name we call today?
- Which of our jobs can run in off-peak hours?
- What share of our input tokens are cache hits?
- How does our agent detect empty answers and leaked tool-call markup?
Red flags
- Customer or regulated data sent before a written legal decision on the data terms.
- A legacy model name in production code that nobody has checked against DeepSeek's latest notice.
- Agent loops with no check for empty content on a stop finish.
- Concurrency past 2,500 with no backoff on HTTP 429.
- Price comparisons that assume cache hits nobody has measured.
Products in this piece
Sources
- Official documentation
- 8
- Public source
- 5
- DeepSeek privacy policy
- DeepSeek Open Platform terms of service (effective Apr 29, 2026)
- DeepSeek API docs: Models and pricing
- DeepSeek API news: V4.1 Flash release and the V4 Pro phase-out (Sep 10, 2026)
- DeepSeek API docs: Context caching
- DeepSeek API docs: Rate limit and isolation
- DeepSeek API docs: Error codes
- DeepSeek API docs: Create chat completion
- BBC News: DeepSeek banned from US government in race with China for AI dominance (Oct 19, 2026)
- deepseek-ai/DeepSeek-V3 issue #1673: answers left in reasoning_content with empty content (Sep 24, 2026)
- deepseek-ai/DeepSeek-V3 issue #1678: deepseek-flash emits internal tool-call markup in content (Sep 30, 2026)
- Hacker News comment on 99% cache hits on DeepSeek's own API (Oct 2, 2026)
- Hacker News comment on 40 billion tokens for US$800 in 30 days on the DeepSeek API (Oct 8, 2026)