Cursor Agent SDK vs Strands Agents

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.

Strands Agents 87

Local-package reading. Official PyPI and npm packages with Python 3.10 and Node 22 stated (20). A public CI workflow runs lint, type checks, unit and integration tests for each package on pull requests to main, plus security-audit workflows, and the latest Python, TypeScript, harness and MCP runs on main passed on 6 November (25). 664 open issues and 1,151 open issues and pull requests on 6 November, with 545 issues opened in the 90 days to 3 November. Of the 50 newest, 12 had a comment and 15 were closed, and 9 of the 40 newest open items carry a bug label. An issue-responder workflow runs on new issues (12). A written semantic versioning policy, experimental APIs kept apart, and deprecations removed only at a major (15). 1.0 since 15 July 2025 (15). 20+25+12+15+15 = 87.

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.

Strands Agents 60

Self-hosted rule. Free Apache-2.0 packages with nothing to buy from the project (20 + 20 + 20). No payment protocol (0). Model calls are paid to the provider. 0+20+20+20 = 60.

Cursor Agent SDK 68

Framework reading. 30 for what leaves the machine by default, 20 for approvals and sandboxing, 15 for prompt injection, 15 for audit and 20 for the security programme. Every model turn goes through Cursor's backend with a Cursor credential, even on a self-hosted server, and the data-use page says Cursor may store and train on prompts and code with Privacy Mode off. Managed hosting stores the repository and agent data whatever the Privacy Mode setting. OpenTelemetry export is off until an endpoint is set, with prompt text and tool payloads behind separate flags, and the npm update check has a documented switch. Install copies skills into ~/.cursor/skills (18). needsApproval parks a tool call for a person, dry runs stub writes and the harness tools take an allowlist, but local.sandbox is off by default, so shell commands auto-approve with the host's environment and file tools reach any path the process can. Hosted deployments enforce an egress allowlist (12). The docs tell you to turn the sandbox on for webhook payloads, diffs and chat, document HMAC and shared-secret auth on webhook routes, and warn that anyone who can talk to the agent can drive Cursor account connectors. The scaffolded memory journal shares turns across sessions, with an instruction to treat it as untrusted (10). Sessions keep every message and tool call, hooks can mirror them for audit, and ctx.approvedBy records the approver (14). security.txt and SECURITY.md with a disclosure address and Cursor's GitHub advisories, no bug bounty found, and no advisory for the three package names in OSV on 2 November (14). SOC 2 and ISO 27001 aren't scored on the framework reading. 18+12+10+14+14 = 68.

Strands Agents 89

Framework reading (telemetry defaults, approvals, guardrails, sandboxing). No usage analytics found in either SDK, and OpenTelemetry is opt-in (25). Interrupts and the harness's interventions gate tool calls behind human approval or Cedar policies, but the default sandbox is the local host (16). Guardrails, PII redaction and trusted message history pages, with Bedrock Guardrails integration (13). OpenTelemetry traces for every model and tool call (15). The AWS Vulnerability Disclosure Program on HackerOne and three advisories in October 2026 published with fixed versions (20). 25+16+13+15+20 = 89.

Cursor Agent SDK 82

Framework reading. Typed TypeScript declarations ship in the package, tools take Zod or JSON Schema, agent-sdk help --json describes every command's flags and exit codes, and GET /v1/info and GET /v1/tools/:name return the discovered surface and each tool's schemas. No OpenAPI document for the HTTP routes (20). cursor.com/llms.txt lists every Agent SDK page with a Markdown twin, and the package ships the docs and an llms.txt (10). The overview has a table of when to use the Agent SDK, Automations or Grok Bot, and the hooks page has a table of what to use instead of a hook for each job (18). Typed config, effect as an enum or predicate, timeArgs checked against the input schema, and slug patterns stated (13). Examples on every page, with error tables for direct tool calls, HTTP 401, 403 and 409, the limit error's JSON and seven exit codes (15). A dated changelog, but only two entries, both from 23 October 2026 (6). 20+10+18+13+15+6 = 82.

Strands Agents 95

Framework reading. Typed Python and TypeScript APIs with a reference for each (25). llms.txt with a Markdown twin of every page (10). The llms.txt and docs say when to use Strands over a hand-written loop and when to take the harness rather than the SDK (18). Tools are typed from decorated functions or Zod schemas (15). Python and TypeScript examples on every page, stop reasons and hook events documented, with no catalogue of exceptions (12). Versioning page and tagged releases per package (15). 25+10+18+15+12+15 = 95.

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.

Strands Agents 87

Python 1.64.0 and TypeScript 1.24.0 tagged on 4 November 2026 (30). Python 1.55.0 on 8 September, 1.61.0 on 14 October, 1.62.0 on 21 October and 1.63.0 on 30 October among many releases in 90 days (20). 664 open issues and 1,151 open issues and pull requests on 6 November, with 545 issues opened in the 90 days to 3 November. Of the 50 newest, 12 had a comment and 15 were closed, and 9 of the 40 newest open items carry a bug label. An issue-responder workflow runs on new issues (12). Both official SDKs are current (15). Dependency floors, security-audit workflows and CI passing on main (10). 30+20+12+15+10 = 87.

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.

Strands Agents 87

Framework reading. An MCPClient is passed straight to the agent in a few lines and its lifecycle is managed, with tool filtering per client (22). Conversation managers, turn limits, token budgets and cancellation bound each run (20). Stop reasons and typed events, and hooks that can retry a model or tool call (16). Retry strategies, session managers that persist and resume a conversation, and interrupts that resume where they paused (17). Two official languages, but the default provider is Bedrock, which needs AWS credentials and model access (12). 22+20+16+17+12 = 87.