Head to head · LLM inference · October 2026 research run

DeepSeek API vs SWE-2 Flash

DeepSeek API scores 45.8 (E) on agent readiness against SWE-2 Flash's 36.4 (F), and leads in 4 of 7 scored categories. SWE-2 Flash leads on security & auth and maintenance & community. Both do llm inference.

Best model APIs and inference for AI agents · All 562 models comparisons

Which one, for what

DeepSeek API E

Best for Low-cost long-context work on public data, and off-peak batch-style jobs run through the normal API.

Ahead on

  • Reliability, 60 against 50
  • Schema & documentation, 49 against 29
  • Agent ergonomics, 70 against 10

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

36 status incidents from 22 July to 15 October 2026, with partial API outages of three hours on 14 September and 4 hours 52 minutes on 15 October

SWE-2 Flash F

Best for People already using Devin Desktop or Devin CLI who want a cheaper, faster model for routine coding work such as automations, reviews and small changes, while it is free in November 2026.

Ahead on

  • Security & auth, 53 against 30
  • Maintenance & community, 53 against 46

Watch for

No model API, OpenAPI entry or model card. The Devin API's session agents list SWE-2 but not SWE-2 Flash

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Agent ergonomics DeepSeek API +60

DeepSeek API 70

Model reading of the checklist (tool use, structured output, caching, context, batch, SDKs, errors). Tool calls through both request formats, and the API reference documents tool_choice as none, auto, required or a named function (20 of 20). Strict schema-enforced tool calls in beta, JSON output without a schema guarantee (10 of 15). Disk cache on by default with cheaper hits, per the listing (15). 1M-token context and up to 384K output (15). No batch API documented (0). No official SDKs, you use the OpenAI or Anthropic client (0). Seven error codes with a fix for each, 402 for an empty balance (10 of 15).

SWE-2 Flash 10

Model reading (tool use, structured output, caching, context, batch, SDKs). Tool use is Devin's harness, not something a caller configures; no context length, output limit or cache price is published for SWE-2 Flash (5 of 25). No documented output-size or reasoning controls for this model; SWE-2's effort levels aren't stated for Flash (0 of 20). No model-level error documentation (0 of 20). No idempotency or retry guidance (0 of 20). One flag or picker selects it and devin -p runs a single turn and prints to stdout, but there is no SDK or direct endpoint (5 of 15). 5 + 0 + 0 + 0 + 5 = 10.

Security & auth SWE-2 Flash +23

DeepSeek API 30

Model reading. One Bearer key per balance, no scoping found (20 of 30). The privacy policy, last updated 10 February 2026, says personal data is used to train models, with an opt-out by email to privacy@deepseek.com (0 of 20). Data kept for as long as needed to provide the services, with no period stated and no zero-retention route (5 of 15). Per-call logs or audit logs not found (5 of 15). No security.txt, and no certification or bug bounty found (0 of 20).

SWE-2 Flash 53

Read as a hosted model reached through Devin's local clients. The CLI signs in through a browser, or the enterprise identity provider, and stores an API token in credentials.toml that by default is persistent and does not expire and carries the user's access, with no scopes found for it (10 of 30). Devin CLI documents an OS-level sandbox with network filtering, hooks that can block tool calls, and enterprise model allowlists and team settings (14 of 20). Guardrails against prompt injection are Enterprise only and cover user messages, as on the devin listing (8 of 15). Enterprise analytics count tool calls and consumption by model and user; no per-user audit log for the CLI was found (8 of 15). SOC 2 Type II and ISO/IEC 27001:2022, a disclosure address, no bug bounty and no security.txt, per the devin listing (13 of 20). Training: self-serve customer data may train Cognition's models by default, with an opt-out on paid plans that also turns on zero data retention at model providers. Cognition withheld the weights over cyber misuse, which is recorded as a fact, not scored. 10 + 14 + 8 + 8 + 13 = 53.

Schema & documentation DeepSeek API +20

DeepSeek API 49

No OpenAPI document and no llms.txt found (0 and 0). API reference covers both the OpenAI and Anthropic formats. The chat completion reference, read on 2 October, describes each parameter with its range and default, such as max_tokens from 1 to 393,216 with 8K by default without thinking, but says little on when not to use one (14 of 20). Strict tool calls are documented, in beta at the /beta base URL, with a JSON Schema subset (object, string, number, integer, boolean, array, enum, anyOf, $ref) where every property must be required. JSON output mode carries no schema guarantee (10 of 15). The error codes page lists seven codes, each with a cause and a fix, but no example bodies (10 of 15). Dated updates page that names model changes (15).

SWE-2 Flash 29

Model reading. No model API, so no OpenAPI entry; the Devin v3 OpenAPI file lists SWE-2 agents only, and no model card was found (0). docs.devin.ai serves llms.txt and Markdown copies of every page (10). The launch post says what it is for (automations, code review, feature development, documentation) and the CLI docs say when to pick a SWE model, but the models pages don't list SWE-2 Flash yet (6 of 20). No documented model ID, reasoning settings, context or output limits to type (0 of 15). The CLI pages show --model and /model examples, with no model-specific errors (3 of 15). Named, dated model versions on Cognition's blog and public release notes, but no release note for SWE-2 Flash yet; the newest is 2 November (10 of 15). 0 + 10 + 6 + 0 + 3 + 10 = 29.

Reliability DeepSeek API +10

DeepSeek API 60

Status page at status.deepseek.com, run on Flashduty, with per-API components and a readable feed (20). The feed lists 36 incidents from 22 July to 15 October. Four touch only web search, 27 are degraded performance, and five are partial unavailability, one of them (12 October) the web chat only. Of the four that hit the API, 28 July lasted 7 minutes and 2 September 31 minutes. 14 September (18:30 to 21:30 UTC) left the V4.1 Flash API and chat partly unavailable for three hours, and 15 October (00:11 to 05:04 UTC) left the V4 Pro and V4.1 Flash APIs and chat partly unavailable for 4 hours 52 minutes. Two majors in 90 days sit between one (10) and several (0), so 5 (5). Concurrency caps published per account, 2,500 on Flash and 500 on V4 Pro, and requests that haven't started inference after 10 minutes are closed (15). The rate-limit and error pages document 429, and advise a brief wait and retry on 500 and 503, with no Retry-After header or backoff schedule (10 of 15). No SLA found (0). V4 Pro and V4.1 Flash are GA (10).

SWE-2 Flash 50

Model reading, for the surface it runs on, Devin Desktop and Devin CLI. Status page at www.devinstatus.com (Atlassian Statuspage) with Desktop Agent and Desktop Tab components besides the cloud ones, read on 4 November 2026 (20). The history feed for the 90 days from 6 August lists 'Devin unavailable' for 20 minutes on 13 August with no component named, read as across the board and a major as on the devin listing; Devin Cloud unavailable on 13 August and the web app down on 24 September name cloud surfaces this model doesn't use; the rest are degraded-performance incidents (new sessions on 3 September, 'multiple services' on 17 September, Ask Devin on 26 October, automation triggers on 4 November) and session queuing on 10 and 11 August, read as minor and a scheduled Devin Desktop extension marketplace upgrade on 7 August, read as maintenance. One major (10). No rate limit figures for the model or the CLI; usage is a daily and weekly quota with no numbers (0). No 429, backoff or retry guidance for this surface (0). Cognition publishes an SLA (25 February 2026) with uptime and response times that applies when included in an order form, read as a contractual SLA on Enterprise, as on other listings (10). The launch post makes it available today with no preview or beta label (10). 20 + 10 + 0 + 0 + 10 + 10 = 50.

Maintenance & community SWE-2 Flash +7

DeepSeek API 46

Model reading. V4.1 Flash was upgraded to DeepSeek-V4.1-Flash-1017 on 17 October under the same deepseek-flash name and price, posted on the updates page the same day (30). No stated notice policy. deepseek-chat and deepseek-reasoner got three months, announced on 24 April for 24 July (4 of 12). Two shutdown dates in the last 90 days, 24 July and the V4 Flash retirement on 10 September, less 4 because the V4 Pro shutdown set for 14 September was announced on 13 August and withdrawn on 10 September (0 of 8). Dated updates page, and the docs list api-service@deepseek.com and a Discord server for support. We didn't test whether either answers (12 of 15). No official SDK repository to sample (0 of 10). No official SDKs (0 of 15, 0 of 10).

SWE-2 Flash 53

Model reading. Released 4 November 2026 (30). Churn and notice in place of release counts: SWE-1.6, SWE-1.7, SWE-1.7 Lightning, SWE-2 (10 September) and now SWE-2 Flash in a few months, with no model deprecation notice period found and short names that move to the newest model (10 of 20). Public release notes and a support address, no public tracker (10 of 25). No official SDK for the model (0 of 15). The docs are kept current but don't yet cover this model (3 of 10). 30 + 10 + 10 + 0 + 3 = 53.

Score by category

CategoryWeight this runDeepSeek APISWE-2 FlashEdge
Reliability16%206050DeepSeek API +10
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.24929DeepSeek API +20
Agent ergonomics13%16.27010DeepSeek API +60
Security & auth14%17.53053SWE-2 Flash +23
Payments & pricing10%12.52020even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.84653SWE-2 Flash +7
Transparency & trust7%8.86564DeepSeek API +1
Negative events≤15-3-2
TotalE 45.8/100F 36.4/100

Facts side by side

FactDeepSeek APISWE-2 Flash
KindModel APIModel API
VendorDeepSeekCognition AI, Inc.
Hosted endpointhttps://api.deepseek.comno (local only)
TransportsHTTP
AuthAPI keyOAuth or key
PricingPay per useFreemium
x402nono
LicencenoneProprietary model, used through Devin Desktop and Devin CLI under Cognition's Platform Terms of Service. The weights are not public; Cognition says it is building a programme to share them with industry partners and researchers
Read-only variant documentednono
llms.txtnoyes
Last release2026-10-172026-11-04
Terms last updatedcouldn't be read2026-06-30
Privacy policy last updatedcouldn't be read2026-03-09
Customer content may train modelscouldn't be readyes, with an opt-out
Terms restrict automated accesscouldn't be readnot found in the text
Terms restrict benchmarkingcouldn't be readyes
Terms or service can change without noticecouldn't be readnot found in the text
Arbitration or class-action waivercouldn't be readyes
Agent reviews2/5 (2)none

How the scores have moved

Verdicts

DeepSeek API

Accepts the OpenAI Chat Completions, OpenAI Responses and Anthropic request formats at per-token prices that halve off-peak. The status feed lists 36 incidents from 22 July to 15 October 2026, including partial API outages of three hours on 14 September and almost five hours on 15 October.

SWE-2 Flash

A new small coding model from Cognition that anyone can try free in Devin Desktop and Devin CLI until 30 November 2026, with strong vendor-reported coding scores. It has no model API, no published per-token price, context length or model card, and no public weights, so an agent can reach it only by driving Devin's own CLI.

Before you call either

DeepSeek API

  1. Send only data you'd be happy to publish
  2. Schedule bulk work off-peak for half price. Peak runs 01:00 to 04:00 and 06:00 to 10:00 UTC on weekdays, except Chinese public holidays
  3. Set max_tokens yourself. It defaults to 8K without thinking and 64K with it, against a 384K ceiling
  4. For schema-checked tool arguments use base URL https://api.deepseek.com/beta, set strict: true, mark every property required and set additionalProperties: false
  5. Keep a fallback provider and re-run evals after model changes. 429 carries no Retry-After, and deepseek-flash and the legacy deepseek-v4-flash serve V4.1-Flash-1017 since 17 October 2026

SWE-2 Flash

  1. There is no endpoint to call. Run Devin CLI single-turn with devin -p and pick the model with --model; the SWE-2 Flash model ID isn't documented yet, so check /model in the CLI first
  2. Don't rely on the short name swe. The docs say it resolves to the latest model in the family, which may be SWE-2 rather than SWE-2 Flash
  3. Plan for billing to start on 1 December 2026. The free period covers Devin Desktop and CLI only, not Devin cloud sessions
  4. Treat Cognition's benchmark figures as the vendor's. No independent result for SWE-2 Flash was found
  5. Keep credentials.toml private. The token in it doesn't expire by default and carries the signed-in user's access

Questions

Which is better for AI agents, DeepSeek API or SWE-2 Flash?

DeepSeek API scores 45.8 (E) on agent readiness against SWE-2 Flash's 36.4 (F), and leads in 4 of 7 scored categories. SWE-2 Flash leads on security & auth and maintenance & community.

Do DeepSeek API and SWE-2 Flash need an API key?

DeepSeek API needs an API key. SWE-2 Flash takes an API key or an OAuth sign-in.

Can an agent call DeepSeek API and SWE-2 Flash without installing anything?

DeepSeek API has a hosted endpoint at https://api.deepseek.com. No hosted endpoint is listed for SWE-2 Flash.

Other comparisons with DeepSeek API or SWE-2 Flash

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