Cursor Agent SDK vs smolagents

Cursor Agent SDK 74

0.3.0 on npm on 25 October 2026, per the 27 October check (npm not re-read on 2 November), and the docs changelog still ends at 0.3.0 of 23 October (30). Five @grok/agent-sdk versions from 22 to 25 October and 29 @cursor/bdk versions since 22 September, per the 27 October check (20). Closed product. A public changelog with two entries and a forum with no Agent SDK tag, so we couldn't see replies to SDK reports (8). The npm package is current and official, TypeScript only (12). Dependencies are current releases, but there's no public CI and the same build goes out under three names with a postinstall script (4). 30+20+8+12+4 = 74.

smolagents 34

v1.26.0 on 29 May 2026, 161 days before this check (10). No release in the 90 days to 6 November (0). 416 open issues and 1,045 open issues and pull requests on 6 November, with 144 issues opened in the 90 days to 3 November. Of the 50 newest, 26 had a comment and 1 was closed. Two 2026 CVE records say the vendor didn't respond to the reporter, and seven commits reached main from 8 August to 6 November (6). Python only, and the package is the current one (10). CI with actions pinned to commit SHAs and Dependabot for actions (8). 10+0+6+10+8 = 34.

Cursor Agent SDK 30

Framework reading of the published rubric. No payment protocol (0). Per-million-token prices for Cursor models, including the default Grok 4.5 with Fast, and plan prices are public, but no price for managed hosting and no statement of which plans cover the Agent SDK were found (15). The package is free and the Free plan needs no card, but its usage is only described as limited agent requests (15). A person signs in through a browser or creates an API key in the dashboard before a model turn runs (0). 0+15+15+0 = 30.

smolagents 60

Self-hosted rule. Free Apache-2.0 package with nothing to buy from the project (20 + 20 + 20). No payment protocol (0). 0+20+20+20 = 60.

Cursor Agent SDK 45

Local-package reading, since the owner runs the framework, with Cursor's hosting as an option. Official npm package with Node 22.13 or newer stated in engines and in the docs, which also say never Bun (20). Closed source, so no public CI or test suite (0). No public issue tracker. github.com/cursor/cursor holds a README and SECURITY.md, and forum.cursor.com has no Agent SDK tag, so there's nothing to count open crashes against. The troubleshooting page lists known failures with fixes (5). A dated changelog of two entries, 0.2.29 and 0.3.0, both 23 October 2026, and 0.3.0 calls out the removed persistent option, but the 27 earlier @cursor/bdk versions and 123 @cursor/july versions have no notes, and one build ships under three package names (5). Version 0.3.0, but the changelog post of 20 October says generally available and the docs changelog labels 0.3.0 the GA release, which we read as declared stable (15). 20+0+5+5+15 = 45.

smolagents 64

Local-package reading. Official PyPI package with Python 3.10 or newer (20). A public tests workflow runs pytest on Python 3.10 and 3.12 for pushes and pull requests; whether main passes wasn't read (15). 416 open issues and 1,045 open issues and pull requests on 6 November, with 144 issues opened in the 90 days to 3 November. Of the 50 newest, 26 had a comment and 1 was closed. Two 2026 CVE records say the vendor didn't respond to the reporter, and seven commits reached main from 8 August to 6 November (6). Release notes on GitHub tags but no changelog file, and the remote WasmExecutor was removed in a minor release (8). 1.0 since 31 December 2024 (15). 20+15+6+8+15 = 64.

Cursor Agent SDK 80

Framework reading, scored on what it takes to run a tool-calling agent with MCP. One file per tool and one file per MCP connection, tools and disallowedTools filters with effects: "read", and an allowlist for the harness's built-in tools (22). Concurrency caps with queued turns, --fields, page tokens and limits on list commands, and a per-session cost view. We found no turn cap or spend cap for a run (12). Built-in routes return { ok: false, error } codes, direct tool calls have documented 400, 404, 409 and 500 codes, and the CLI has seven exit codes (18). Reads and idempotent calls retry up to three times, writes run once, MCP readOnlyHint and idempotentHint decide retries for connection tools, and dry-run sessions stub writes (20). agent-sdk init scaffolds a working project and every agent field is optional, but the framework is TypeScript only (8). 22+12+18+20+8 = 80.

smolagents 68

Framework reading. MCPClient loads an MCP server's tools in a few lines (20). max_steps, planning intervals and final_answer_checks bound a run (16). Errors from tools and code go back to the model as observations (14). No built-in retry, idempotency or resume beyond replaying memory (8). Few required parameters and many providers, Python only, and the default model needs a Hugging Face token (10). 20+16+14+8+10 = 68.

Cursor Agent SDK 71

Closed source. LICENSE.md reads All rights reserved, with use under Cursor's Terms of Service of 3 September 2026 (15). The data-use page says Privacy Mode keeps Customer Data out of training with zero-retention agreements at model providers, and that with it off Cursor may store and train on code and prompts. The deployment page says managed hosting stores the repository and agent data the same way under Privacy Mode and refuses Privacy Mode (Legacy). No retention periods are stated, and subprocessors are on a trust portal (14). No deprecation policy. The early-alpha migration guide, the persistent removal and the semantic-search removal are documented with error messages but only the changelog entry carries a date (6). OpenTelemetry and the update check are documented with switches. What the Cursor backend logs from turns is covered only by the data-use page (14). 15+14+6+14 = 49.

smolagents 65

Apache-2.0 (30). The library stores nothing itself; the default model sends prompts to Hugging Face's inference providers, which the docs show (20). Breaking removals such as WasmExecutor shipped in minor releases, without a written deprecation policy (5). No telemetry, though no page states it (12). 30+20+5+12 = 67.