# Cursor Agent SDK vs AI SDK

> AI SDK scores 89.8 (AA) to Cursor Agent SDK's 63.7 (B) for agent frameworks. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-vercel-ai-sdk
- Markdown: https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-vercel-ai-sdk.md (~5,050 tokens)
- Site index for agents: https://www.anchorterminal.com/llms.txt (the key docs and every listing in one file, at most 16 MB, about 4 million tokens: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- DNS: dig +short TXT <slug>.grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.<category>. and <a>.vs.<b>. under the zone, and the same under grade.letme.dev)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-11-07

AI SDK scores 89.8 (AA) on agent readiness against Cursor Agent SDK's 63.7 (B), and leads in every scored category. Both do agent frameworks.

- Cursor Agent SDK: grade B, 63.7/100, rank #501 of 1486. Markdown https://www.anchorterminal.com/tools/cursor-agent-sdk.md · JSON https://www.anchorterminal.com/api/v1/tools/cursor-agent-sdk.json
- AI SDK: grade AA, 89.8/100, rank #1 of 1486. Markdown https://www.anchorterminal.com/tools/vercel-ai-sdk.md · JSON https://www.anchorterminal.com/api/v1/tools/vercel-ai-sdk.json
- Best agent frameworks and SDKs: https://www.anchorterminal.com/best/frameworks/index.md
- All 171 frameworks comparisons: https://www.anchorterminal.com/compare/frameworks/index.md

## Which one, for what

### Cursor Agent SDK (B)

Good for: Teams already on Cursor who want version-controlled agents for pull request review, triage and Slack, with evals in CI and one-command hosting.

Watch for: Closed source under Cursor's terms, with no public repository, CI or issue tracker

### AI SDK (AA)

Good for: TypeScript teams building agents and chat UIs who want one API across many providers and a short path to MCP.

Ahead on:
- Reliability, 93 against 45
- Schema & documentation, 100 against 82
- Agent ergonomics, 95 against 80
- Security & auth, 90 against 68
- Payments & pricing, 60 against 30
- Maintenance & community, 97 against 74
- Transparency & trust, 89 against 71

Also in its favour:
- Agent-ready, a grade of BB or better
- Open source

Watch for: TypeScript only, and `ai` 7.x needs Node 22 or newer


## Why the edge

### Reliability: AI SDK +48

- 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.
- AI SDK (93): Official npm packages, with `ai` 7.x requiring Node 22 or newer (20). A public CI workflow with lint, type checks, unit tests, Node-version tests, MCP tests on Windows and e2e tests runs on every push to main, and the newest completed CI runs on main passed on 6 November (25). 1,517 open issues and pull requests on 6 November from GitHub's API, with 1,059 issues opened in the 90 days to 3 November; 47 of the 50 newest had a comment and 32 were closed (18). A written versioning page with breaking changes only in majors, experimental_ prefixes for unstable APIs and a migration guide per major (15). 7.0.163 (15). 20+25+18+15+15 = 93, up from 73 on 6 October, when GitHub couldn't be read.

### Payments & pricing: AI SDK +30

- 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.
- AI SDK (60): No payment protocol (0). Scored on the AI Gateway, the paid option, which charges providers' list prices with no markup and lists per-model rates and add-on prices without a login (20). The Apache 2.0 package installs with no card (20) and no account, and provider packages run any model, including local ones (20).

### Maintenance & community: AI SDK +23

- 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.
- AI SDK (97): 7.0.163 on 2026-11-05 (30). 226 stable npm releases of `ai` across the 7.x, 6.x and 5.x lines in the 90 days to 6 November, 70 of them since 6 October (20). 47 of the 50 newest issues commented and 32 closed, with triage automation and backport workflows (22). `ai` and the provider packages are current, and 6.x and 5.x still get patches (15). Dependabot configured and CI passing on main (10). 30+20+22+15+10 = 97.

### Security & auth: AI SDK +22

- 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.
- AI SDK (90): No telemetry until an OpenTelemetry integration is registered. String model IDs route to Vercel's AI Gateway by default, which is documented and needs a Vercel key, so it isn't silent (25). Per-tool approval, HMAC-signed approvals against forged client history, and Open Policy Agent rules in @ai-sdk/policy-opa, though sandboxes are experimental (20). ToolLoopAgent rejects system messages in prompts by default as an injection risk, URL fetches are checked against private addresses, and MCP HTTP transport refuses redirects by default, but there's no guardrail primitive (10). OpenTelemetry spans for every model and tool call to any backend, opt-in (15). HackerOne programme, a valid security.txt, SECURITY.md and two low-severity advisories published with fixed versions (20). Framework reading, so SOC 2 isn't scored.

### Schema & documentation: AI SDK +18

- 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.
- AI SDK (100): Typed TypeScript API with a reference section for every function (25). llms.txt and a Markdown copy of each page (10). The docs say when to use each piece, such as a table of WorkflowAgent against ToolLoopAgent, a when-to-use section for subagents and harnesses, and HTTP over stdio for MCP in production (20). Tools take Zod or JSON Schema inputs (15). 38 error types documented in the reference, with error-handling guides and examples throughout (15). Versioning page and a changesets CHANGELOG per package (15).

### Transparency & trust: AI SDK +18

- 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.
- AI SDK (89): Apache 2.0 (30). The library stores nothing. The AI Gateway's ZDR page says it doesn't retain prompts or outputs and per-request ZDR is available on Pro and Enterprise, and Vercel's privacy notice is dated 1 June 2026, but we didn't read a DPA or subprocessor list (22). Deprecated APIs are removed only at majors with a migration guide, and 6.x and 5.x keep getting releases, without a written support window (14). Telemetry is opt-in and documented, with switches for inputs and outputs (20).

## Score by category

| Category | Weight | Cursor Agent SDK | AI SDK | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 45 | 93 | AI SDK +48 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 82 | 100 | AI SDK +18 |
| Agent ergonomics | 13% (16.2 this run) | 80 | 95 | AI SDK +15 |
| Security & auth | 14% (17.5 this run) | 68 | 90 | AI SDK +22 |
| Payments & pricing | 10% (12.5 this run) | 30 | 60 | AI SDK +30 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 74 | 97 | AI SDK +23 |
| Transparency & trust | 7% (8.8 this run) | 71 | 89 | AI SDK +18 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **63.7 · B** | **89.8 · AA** | |

## Facts side by side

| Fact | Cursor Agent SDK | AI SDK |
| --- | --- | --- |
| Kind | Agent framework | Agent framework |
| Vendor | Cursor | Vercel Inc. |
| Hosted endpoint | no (local only) | no (local only) |
| Transports |  |  |
| Auth | OAuth or key | API key |
| Pricing | Your plan | Free |
| x402 | no | no |
| Licence | Proprietary. The package's LICENSE.md reads "© Anysphere Inc. All rights reserved", with use subject to Cursor's Terms of Service (updated 3 September 2026). No source repository is published | Apache-2.0 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-25 | 2026-11-05 |
| Terms last updated | 2026-09-03 | 2026-06-01 |
| Privacy policy last updated | 2026-09-29 | 2026-06-01 |
| Customer content may train models | not found in the text | yes, with an opt-out |
| Terms restrict automated access | yes | not found in the text |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | yes | not found in the text |
| Arbitration or class-action waiver | yes | yes |
| Popularity | none | 28k stars, 44.9M npm/wk |

## How the scores have moved

### Cursor Agent SDK

- +0.1 on 28 October 2026: checklist

### AI SDK

No score change since it was listed.

## Verdicts

**Cursor Agent SDK.** An agent-as-code framework with typed tools, declared read and write effects that drive retries and dry runs, an approval gate per tool and evals that assert on tool calls. It's closed source, every model turn runs through Cursor's backend on a Cursor plan, local sandboxing is off by default, and the changelog has two entries.

**AI SDK.** A TypeScript agent toolkit with ToolLoopAgent, a built-in MCP client, per-tool approvals that can be HMAC-signed, opt-in OpenTelemetry and durable runs through WorkflowAgent. It ships three major versions in 14 months (5.0, 6.0, 7.0), each with a migration guide, and plain string model IDs route through Vercel's AI Gateway unless another provider is set.

## Before you call either

### Cursor Agent SDK

1. Install `@grok/agent-sdk`, not `@cursor/agent-sdk` from the launch post. That name answers 404 on npm
2. Set `local.sandbox` before a turn reads webhook payloads, pull request diffs or chat. Without it shell commands auto-approve with the host's credentials
3. Give every tool an `effect`. A tool without one counts as a write, runs once and is stubbed in dry runs
4. Start `agent-sdk serve` with `--bearer-token` on any shared host. `--allow-anonymous` admits every caller as one principal
5. Delete bot/hooks/memory.ts when sessions serve different people. The journal shares each turn's message and result with later turns

### AI SDK

1. Pass a provider instance such as openai('model') if traffic shouldn't go through Vercel's AI Gateway
2. Set toolApproval on tools that write, and experimental_toolApprovalSecret when approvals come back from a browser
3. Raise or replace the default stop condition of 20 steps with stopWhen
4. Close the MCP client after the run, and use HTTP transport outside local development
5. Set recordInputs and recordOutputs to false when spans would carry secrets

## Questions

### Which is better for AI agents, Cursor Agent SDK or AI SDK?

AI SDK scores 89.8 (AA) on agent readiness against Cursor Agent SDK's 63.7 (B), and leads in every scored category.

### Are Cursor Agent SDK and AI SDK open source?

No open-source release is listed for Cursor Agent SDK. AI SDK is open source (Apache-2.0).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-vercel-ai-sdk.json, and with the fewest tokens: https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-vercel-ai-sdk.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "cursor-agent-sdk", "b": "vercel-ai-sdk"}`. From a terminal: `anchor compare cursor-agent-sdk vercel-ai-sdk`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/cursor-agent-sdk.json and https://www.anchorterminal.com/api/v1/tools/vercel-ai-sdk.json

## Other comparisons with Cursor Agent SDK or AI SDK

- [AgentOS vs Cursor Agent SDK](https://www.anchorterminal.com/compare/agentos-vs-cursor-agent-sdk.md)
- [AgentOS vs AI SDK](https://www.anchorterminal.com/compare/agentos-vs-vercel-ai-sdk.md)
- [Agno vs Cursor Agent SDK](https://www.anchorterminal.com/compare/agno-vs-cursor-agent-sdk.md)
- [Agno vs AI SDK](https://www.anchorterminal.com/compare/agno-vs-vercel-ai-sdk.md)
- [BoxLang AI vs Cursor Agent SDK](https://www.anchorterminal.com/compare/boxlang-ai-vs-cursor-agent-sdk.md)
- [BoxLang AI vs AI SDK](https://www.anchorterminal.com/compare/boxlang-ai-vs-vercel-ai-sdk.md)
- [Claude Agent SDK vs Cursor Agent SDK](https://www.anchorterminal.com/compare/claude-agent-sdk-vs-cursor-agent-sdk.md)
- [Claude Agent SDK vs AI SDK](https://www.anchorterminal.com/compare/claude-agent-sdk-vs-vercel-ai-sdk.md)
- [CrewAI vs Cursor Agent SDK](https://www.anchorterminal.com/compare/crewai-vs-cursor-agent-sdk.md)
- [CrewAI vs AI SDK](https://www.anchorterminal.com/compare/crewai-vs-vercel-ai-sdk.md)
- [Cursor Agent SDK vs Docker Agent](https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-docker-agent.md)
- [Cursor Agent SDK vs Agent Development Kit (ADK)](https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-google-adk.md)
- [Cursor Agent SDK vs guilds.run](https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-guilds-run.md)
- [Cursor Agent SDK vs LangGraph](https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-langgraph.md)
- [Cursor Agent SDK vs LlamaIndex Framework](https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-llamaindex.md)
- [Cursor Agent SDK vs Mastra](https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-mastra.md)
- [Cursor Agent SDK vs Microsoft Agent Framework](https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-microsoft-agent-framework.md)
- [Cursor Agent SDK vs OpenAI Agents SDK](https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-openai-agents-sdk.md)
- [Cursor Agent SDK vs Pydantic AI](https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-pydantic-ai.md)
- [Cursor Agent SDK vs smolagents](https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-smolagents.md)
- [Cursor Agent SDK vs Strands Agents](https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-strands-agents.md)
- [Cursor Agent SDK vs TradingAgents](https://www.anchorterminal.com/compare/cursor-agent-sdk-vs-tradingagents.md)
- [Docker Agent vs AI SDK](https://www.anchorterminal.com/compare/docker-agent-vs-vercel-ai-sdk.md)
- [Agent Development Kit (ADK) vs AI SDK](https://www.anchorterminal.com/compare/google-adk-vs-vercel-ai-sdk.md)
- [guilds.run vs AI SDK](https://www.anchorterminal.com/compare/guilds-run-vs-vercel-ai-sdk.md)
- [LangGraph vs AI SDK](https://www.anchorterminal.com/compare/langgraph-vs-vercel-ai-sdk.md)
- [LlamaIndex Framework vs AI SDK](https://www.anchorterminal.com/compare/llamaindex-vs-vercel-ai-sdk.md)
- [Mastra vs AI SDK](https://www.anchorterminal.com/compare/mastra-vs-vercel-ai-sdk.md)
- [Microsoft Agent Framework vs AI SDK](https://www.anchorterminal.com/compare/microsoft-agent-framework-vs-vercel-ai-sdk.md)
- [OpenAI Agents SDK vs AI SDK](https://www.anchorterminal.com/compare/openai-agents-sdk-vs-vercel-ai-sdk.md)
- [Pydantic AI vs AI SDK](https://www.anchorterminal.com/compare/pydantic-ai-vs-vercel-ai-sdk.md)
- [smolagents vs AI SDK](https://www.anchorterminal.com/compare/smolagents-vs-vercel-ai-sdk.md)
- [Strands Agents vs AI SDK](https://www.anchorterminal.com/compare/strands-agents-vs-vercel-ai-sdk.md)
- [TradingAgents vs AI SDK](https://www.anchorterminal.com/compare/tradingagents-vs-vercel-ai-sdk.md)

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