agent-browser vs Kernel

agent-browser 70

0.41.1 on 30 October 2026 (30). 18 tagged releases in the 90 days from 3 August, 0.34.0 on 10 August to 0.41.1, read from a clone (20). 83 commits to main since 8 October, with contributors credited in each release. Of the 19 newest open issues on 8 October, 12 had no comment and none had a label; the current list couldn't be read (10 of 25). Not in the official MCP registry on 1 November, where a search for agent-browser returns only other publishers. Homebrew is current and crates.io is 22 minor versions behind (5 of 15). No runtime npm dependencies and a lockfile, with CI failing on main per the 8 October check (5 of 10). 30 + 20 + 10 + 5 + 5 = 70.

Kernel 90

The changelog's latest entry is 16 October 2026 and the MCP server repository has commits on 6 November (30). More than three dated changes in 90 days, scoped keys, memory tiers, GPU tier and card payments among them (20). A closed service with a public changelog, Discord, email support and an open-source MCP server with 210 commits since 8 August (15). Official SDKs in three languages, and the MCP server in the registry as com.onkernel/kernel-mcp-server 1.1.0 (15). CI and tests in the MCP repository (10). 30 + 20 + 15 + 15 + 10 = 90.

agent-browser 67

The tool needs no credential. Site passwords sit in a local vault encrypted with AES-256-GCM and are filled without reaching the model, while saved state files are plaintext unless a key is set (22 of 30). Domain allowlist, action policy file and confirmation for chosen action categories, all opt-in, with no restriction by default, though auto-discovered project config files can no longer set executables, browser arguments or plugins since 0.39.3 (16 of 20). Content boundary markers with a per-process nonce, output caps and a written threat model with known limitations, also opt-in (12 of 15). A local dashboard shows a command and result feed, with no persistent audit log found (7 of 15). No SECURITY.md in the repository on 1 November and no advisory on OSV, though 0.39.3, 0.40.0 and 0.41.0 fixed security flaws in the release notes. vercel.com's security.txt names HackerOne, per the 8 October check (10 of 20). 22 + 16 + 12 + 7 + 10 = 67.

Kernel 81

Scoped API keys with resource and action policies, project scoping and expiry, and OAuth 2.1 for MCP with project-limited tokens (30). Least privilege through scoped keys, a payment cap for cards through the MCP server and vault writes that need their own action (16). Pages an agent browses are untrusted, and we found no prompt-injection guidance in the docs read (4). Audit log search and export on Start-Up and above (13). SOC 2 Type II, HIPAA, PCI DSS and ISO 27001 on the security page and a HackerOne bounty (18). 30 + 16 + 4 + 13 + 18 = 81, before the deduction for the November 2026 incident.

agent-browser 84

Graded on the CLI and its MCP server. Every MCP tool has a JSON Schema input with additionalProperties false, and since 0.41.0 the full catalogue ships as @agent-browser/sandbox/mcp-tools.json (156 tools at 0.41.1), and agent-browser.schema.json covers the config file (25). llms.txt and a Markdown copy of each docs page at agent-browser.dev, re-read on 1 November (10). Tool descriptions are one line, such as Scroll the page or an element, with parameter descriptions that say when to omit a field. Few say when not to use a tool (12). Enums, minimums, defaults and required lists, with a free-form extraArgs string array on every tool (12). Many CLI examples and a --json result shape, with error codes such as tab_gone named in passing and no error catalogue found (10). Versioned releases and CHANGELOG.md for each (15). 25 + 10 + 12 + 12 + 10 + 15 = 84.

Kernel 93

OpenAPI at kernel.sh/openapi.json and per-endpoint Markdown reference (25). llms.txt with 423 entries and a Markdown twin for each page (10). Endpoint descriptions say when to use alternatives ("For interactive browsing, use GET /audit-logs", pools for bursty traffic) (17). Typed parameters with enums and limits such as memory sizes and timeout maximums (13). Code samples in TypeScript, Python and Go, and documented status codes such as 409 and 204 on pool acquire (13). A dated public changelog and SDK changelogs (15). 25 + 10 + 17 + 13 + 13 + 15 = 93.

agent-browser 48

Scored as local software. Official npm and Homebrew packages, Homebrew at 0.41.1 on 1 November 2026 with native binaries for five platforms, but crates.io still holds 0.19.0 from 14 March 2026 while the README lists cargo install (18 of 20). Public CI runs Rust tests on Linux, macOS and Windows plus native end-to-end tests. The ten most recent runs on main, 1 to 8 October 2026, concluded in failure, per the 8 October check. GitHub's API wasn't readable on 1 November, so the current state is unchecked (10 of 25). 840 open issues and pull requests and most of the newest without a reply, per the 8 October check. The three reports it named (#2032, #2056, #2031) were fixed in 0.39.1, 0.39.2 and 0.39.4, but the current issue list couldn't be read (10 of 25). Every release has a changelog entry and breaking changes get their own heading, on a 0.x line (10 of 15). 0.41.1 with a Labs badge and no stable declaration (0). 18 + 10 + 10 + 10 + 0 = 48.

Kernel 53

Hosted reading. status.kernel.sh on incident.io with a public incident feed (20). In the 90 days from 8 August it lists browser connection failures on 10 September (54 minutes, major), frozen popups on 1 October (71 minutes, major), elevated API errors on 19 October (4 minutes, critical), proxy failures on 23 October (65 minutes, major) and browser creation errors on 4 November (29 minutes, major), plus minor ones. Several majors, two of them an hour or more (0). Rate limits are per organisation with headers on every response, and concurrency is published per plan, but the create-rate numbers aren't (8). 429 with Retry-After, SDK retries with a typed error, safe retry with the same MPP credential and 409 on concurrent pool changes (15). The terms mention service levels in an order form but no public SLA was found (0). The API and MCP server carry no beta label (10). 20 + 0 + 8 + 15 + 0 + 10 = 53.

agent-browser 60

Free, self-hosted, nothing to buy, so 20 + 20 + 20 under the self-hosted rule. No payment protocol (0). 0 + 20 + 20 + 20 = 60.

Kernel 65

MPP on POST /mpp/browsers, a 402 challenge paid with a Stripe shared payment token through Link, covering one browser product only, not the API or MCP server (20). Per-second prices public without a login (20). The Developer plan is free with $5 of monthly credit, but whether signup needs a card wasn't stated on the pages read (10). Through MPP an agent gets a browser with no account or key, though a person approves each Link payment (15). 20 + 20 + 10 + 15 = 65.