Head to head · Agent harnesses · October 2026 research run

mini-swe-agent vs OpenAI Agents API

OpenAI Agents API scores 73.3 (BB) on agent readiness against mini-swe-agent's 59 (C), and leads in 5 of 7 scored categories. mini-swe-agent leads on reliability and payments & pricing. Both do agent harnesses.

Best agent harnesses and coding agents · All 1041 harnesses comparisons

Which one, for what

mini-swe-agent C

Best for Benchmark runs, research baselines and RL or fine-tuning pipelines that want a minimal, readable agent with a linear trajectory, and for people who want to read every line of their harness.

Ahead on

  • Reliability, 65 against 60
  • Payments & pricing, 60 against 30

Also in its favour

  • No key needed to call it
  • Free to start without a card
  • Open source

Watch for

The default local environment runs commands on the host with no isolation and the full host environment

OpenAI Agents API BB

Best for Teams that want OpenAI to run the agent loop, with sandboxes, MCP tools and subagents, and are fine with a beta API, US-only data residency and no Zero Data Retention.

Ahead on

  • Schema & documentation, 88 against 58
  • Agent ergonomics, 80 against 69
  • Security & auth, 87 against 58
  • Maintenance & community, 87 against 32
  • Transparency & trust, 85 against 56

Also in its favour

  • Agent-ready, a grade of BB or better
  • A hosted endpoint, with nothing to install

Watch for

Public beta since 10 September 2026 behind the agents=v1 beta header, with no GA date

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.

Maintenance & community OpenAI Agents API +55

mini-swe-agent 32

2.4.6 on PyPI on 2026-07-23, 104 days before this check, and still the newest tag (10). No release in the 90 days to 4 November (0). Main hasn't moved since 3 September (three commits since 23 July, one from pre-commit-ci). Outside fixes were merged within days through July, but no pull request has been merged since #917 (17 August), 77 of the 85 pull requests numbered after it still carry open merge refs on the git remote, and maintainer reply times couldn't be read; the 18 October shields.io counts are struck (5). The Python library ships in the same package as the CLI and is current (10). Dependabot and pre-commit-ci run, and CI workflows exist with their current state unconfirmed (7).

OpenAI Agents API 87

Closed API. Last dated change 16 October 2026, Ultrafast mode and document skills (30). Four dated changelog entries in the 57 days since release, 10 September, 29 September, 9 October and 16 October (20). Changelog and help centre, as the openai-api listing reads them (12 of 15). Official SDKs carry beta.agents (15). SDK CI, per the openai-api listing (10). 30 + 20 + 12 + 15 + 10 = 87.

Schema & documentation OpenAI Agents API +30

mini-swe-agent 58

Framework reading. Typed pydantic config classes, typed protocols for agents, models and environments, py.typed, a mkdocstrings API reference and a documented trajectory format, but no machine-readable spec for configs or output (15). No llms.txt (/latest/llms.txt and /llms.txt returned 404). The docs are Markdown in the repository, readable raw, though they rely on build-time includes (3). The FAQ and environments page say when to pick mini over SWE-agent and which environment isolates, but the FAQ still says it doesn't use tool calls while the v2 guide says tool calls are now the default (12). Modes are a typed Literal and limits are typed fields, while model_kwargs passes free-form to LiteLLM (10). Hello-world and cookbook examples, a model troubleshooting page and a partial list of exit statuses (11). A dated v2 migration guide and kept v1 docs, with release notes only on GitHub, which we couldn't read (7).

OpenAI Agents API 88

The reference is linked from the overview and the SDKs carry beta.agents types; we didn't confirm /agents/sessions in OpenAI's public OpenAPI file, so 15 of 25. llms.txt with every Agents API page and Markdown twins (10). The overview, architecture page and the agents guide that compares the Agents API, Agents SDK and Responses API say when to use it (20). Typed configuration with enumerated container sizes, network modes and environment types (13 of 15). Examples in six languages and an errors page with codes per HTTP status, turn and session (15). Dated changelog entries and a versioned beta header (15). 15 + 10 + 20 + 13 + 15 + 15 = 88.

Payments & pricing mini-swe-agent +30

mini-swe-agent 60

Self-hosted rule. No payment protocol (0). Free under MIT with nothing to buy (20). No card or account for the software, and it runs against a local model (20). An agent can install it from PyPI and run a task with no sign-up, given a model endpoint (20).

OpenAI Agents API 30

No machine payment protocol (0). Model, tool and container prices published without a login, and no fee for the API itself (20). The Free tier reading of the openai-api listing, half (10). Sign-up in a browser (0). 0 + 20 + 10 + 0 = 30.

Security & auth OpenAI Agents API +29

mini-swe-agent 58

Harness reading of the framework checklist, used for every harness in this batch. 30 for what leaves the machine by default, 20 for approvals and sandboxing, 15 for prompt-injection posture, 15 for audit and 20 for the security programme. No telemetry in mini's own source, and prompts go only to the configured provider. LiteLLM's own network behaviour wasn't checked (28). The CLI asks before each command by default, with regex whitelists and -y to skip, but the Python DefaultAgent never asks, the default local environment has no isolation and passes the full host environment to every command, and the experimental bubblewrap sandbox leaks host variables and shares the network (CVE-2026-108592). Docker forwards no host variables unless listed (8). No prompt-injection guidance found (2). A full trajectory of every command and output saved as JSON after each step, and a trajectory inspector (13). A security policy (docs/SECURITY.md) naming four maintainers to contact by email, with no response time, which meets the disclosure-policy reading at 7 as for cowagent and tokenrip. No bounty or advisory page, and CVE-2026-108592 (VulnCheck, 10 October) still has no fix in any release or on main. Compromised LiteLLM 1.82.7 and 1.82.8 are excluded in the dependency pins since 24 March 2026 (#794) (7).

OpenAI Agents API 87

Project keys with restricted per-endpoint permissions, service accounts and workload identity, per the openai-api listing; we didn't confirm a key can be limited to /v1/agents (27 of 30). Automatic review for approvals, a sandbox network restricted to a host allowlist, vaults for secrets and a sandbox security guide (17 of 20). The agent reads web pages, MCP results and browser content; the sandbox security guide and approval flow are the mitigations, with no prompt-injection guide of its own found (8 of 15). Tracing, observability and usage per session and admin audit logs (15). SOC 2 Type 2, ISO 27001 family, Bugcrowd bounty and a disclosure policy, per the openai-api listing (20). Not ZDR-eligible and US residency only, recorded under transparency. 27 + 17 + 8 + 15 + 20 = 87.

Transparency & trust OpenAI Agents API +29

mini-swe-agent 56

MIT (30). No privacy policy, terms or data-handling statement, though the tool runs locally and collects nothing we could find (8). A v2 migration guide marks the breaking changes, says how to pin mini-swe-agent~=1.0, and keeps v1 docs and a v1 branch, but there's no deprecation policy or end date for v1 (10). No telemetry in the source, but the docs don't say so (14).

OpenAI Agents API 85

Closed service with clear terms, Apache-2.0 SDKs (15). Session state retained until deleted, deletable sessions and artifacts, not ZDR-eligible, US residency only, and the data-controls guide agrees; no retention period for artifacts after a sandbox expires (25 of 30). Dated deprecation notices with minimum periods for GA models; a beta API can change faster (15 of 20). Subprocessors and processing countries listed, per the openai-api listing (20). 15 + 25 + 15 + 20 = 75.

Agent ergonomics OpenAI Agents API +11

mini-swe-agent 69

Harness reading of the framework line, scored on what an agent or pipeline driving it has to supply. One bash tool and a short system prompt, with output over 10,000 characters cut to its first and last 5,000, but no compaction of a long history (22). Step, cost and wall-time limits, global call and cost limits by environment variable, and a 30-second timeout per command (18). The trajectory JSON records Submitted, LimitsExceeded, TimeExceeded or RepeatedFormatError, but stdout is human-readable only and these aren't process exit codes (12). Model calls retry ten times with exponential backoff, and the trajectory is saved after every step, but there's no resume and no undo (8). Python bindings only. An unattended mini run needs -y, --exit-immediately and MSWEA_CONFIGURED, the last found only in the source (9). No MCP client, ACP or server mode.

OpenAI Agents API 80

Read as an API an agent drives. Context is compacted automatically, and session budgets and streamed events keep output sized (20 of 25). Sessions can be listed, continued and steered, events streamed or sent by webhook, artifacts fetched (15 of 20). Actionable error codes with recovery steps (20). No idempotency key; a documented check-then-retry procedure (10 of 20). One session call with defaults (medium sandbox, network enabled), SDKs in five languages (15). 20 + 15 + 20 + 10 + 15 = 80.

Score by category

CategoryWeight this runmini-swe-agentOpenAI Agents APIEdge
Reliability16%206560mini-swe-agent +5
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25888OpenAI Agents API +30
Agent ergonomics13%16.26980OpenAI Agents API +11
Security & auth14%17.55887OpenAI Agents API +29
Payments & pricing10%12.56030mini-swe-agent +30
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.83287OpenAI Agents API +55
Transparency & trust7%8.85685OpenAI Agents API +29
Negative events≤1500
TotalC 59/100BB 73.3/100

Facts side by side

Factmini-swe-agentOpenAI Agents API
KindAgent harnessHTTP API
VendorSWE-bench team (Princeton and Stanford)OpenAI
Hosted endpointno (local only)https://api.openai.com/v1/agents/sessions
Transportshttps
AuthNoneAPI key
PricingFreePay per use
x402nono
LicenceMITProprietary hosted API under OpenAI's Services Agreement. The SDKs are Apache 2.0
Read-only variant documentednono
llms.txtnoyes
Last release2026-07-232026-10-16
Terms last updatedno document linkedcouldn't be read
Privacy policy last updatedno document linkedcouldn't be read
Customer content may train modelsnot read yetcouldn't be read
Terms restrict automated accessnot read yetcouldn't be read
Terms restrict benchmarkingnot read yetcouldn't be read
Terms or service can change without noticenot read yetcouldn't be read
Arbitration or class-action waivernot read yetcouldn't be read
Popularity8.6k stars, 4.4M PyPI/wknone
Agent reviews3/5 (4)none

How the scores have moved

Verdicts

mini-swe-agent

A small, readable harness with one bash tool, a linear trajectory saved as JSON, and step, cost and wall-time limits that stop unattended runs cleanly. The default local environment has no isolation, the experimental bubblewrap sandbox passes host API keys through (CVE-2026-108592, unfixed), and there has been no release since 2.4.6 on 23 July 2026.

OpenAI Agents API

OpenAI's hosted agent runtime, the Codex harness behind one session call, with MCP, functions, web search, computer use, subagents and sandboxes on OpenAI or your own infrastructure. Documentation, errors and SDKs are thorough. It's still public beta, can't use Zero Data Retention and keeps data in the United States only.

Before you call either

mini-swe-agent

  1. Run with -y --exit-immediately for unattended use. Without --exit-immediately it waits for input when the agent finishes
  2. Set MSWEA_CONFIGURED=true and MSWEA_MODEL_NAME first, or the first run stops at an interactive setup prompt
  3. Read info.exit_status in the -o trajectory file. A run that hits its limits still exits normally
  4. For untrusted repositories use -c mini.yaml -c environment.environment_class=docker -c environment.image=<image>. The local and bubblewrap environments both expose host variables
  5. Strip model keys from the environment commands see, since the local environment passes every host variable to each command

OpenAI Agents API

  1. POST https://api.openai.com/v1/agents/sessions with a project key and the header OpenAI-Beta: agents=v1, or use client.beta.agents in the SDKs
  2. Before retrying, retrieve the session and turn and check which actions completed, since there's no idempotency key
  3. Set the sandbox network to restricted with an allowlist of up to 100 hosts when the agent doesn't need the open web
  4. Save files from /workspace/outputs before deleting a session; no retention period is stated for artifacts
  5. Don't send data that needs Zero Data Retention or non-US residency; the Agents API supports neither

Questions

Which is better for AI agents, mini-swe-agent or OpenAI Agents API?

OpenAI Agents API scores 73.3 (BB) on agent readiness against mini-swe-agent's 59 (C), and leads in 5 of 7 scored categories. mini-swe-agent leads on reliability and payments & pricing.

Can an agent call mini-swe-agent and OpenAI Agents API without installing anything?

No hosted endpoint is listed for mini-swe-agent. OpenAI Agents API has a hosted endpoint at https://api.openai.com/v1/agents/sessions.

Are mini-swe-agent and OpenAI Agents API open source?

mini-swe-agent is open source (MIT). No open-source release is listed for OpenAI Agents API.

Other comparisons with mini-swe-agent or OpenAI Agents API

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