Anchor Browser vs Kernel

Anchor Browser 30

No machine payment protocol was confirmed on Anchor's own endpoints. A blog post dated 29 August 2025 shows x402 on POST /v1/sessions, but our unpaid request on 1 November 2026 returned 401 "Unauthorized, please log in.", as on 8 October, and the docs don't describe it. The session option named x402 lets a browser pay other sites (0). Per-browser, per-hour, per-GB, per-step and, now, per-run prices for Automation Tasks (0.1 credits, $0.10, with failed runs not charged the task fee) are published without login (20). The Free plan has $5 of credits a month. Agent Access, which granted 1 credit with no account and no card, answered "Agent Access is disabled" on 1 November, and whether dashboard sign-up asks for a card wasn't read, so half, as smartsheet's unconfirmed trial (10). With Agent Access disabled, a key comes from a dashboard account at app.anchorbrowser.io, which a person creates in a browser (0). 0 + 20 + 10 + 0 = 30.

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.

Anchor Browser 57

The newest dated releases are the TypeScript SDK 1.0.0 on npm on 26 July 2026, per the 8 October check, and the Python SDK 1.0.1, tagged in its repository on 28 July, 96 days before 1 November. Neither repository has a commit after 28 July. The pricing page dates its AI step prices from 21 August 2026, 72 days before, the newest dated change to the service (20). In the 90 days from 3 August that pricing change is the only dated entry we found, and blog announcements carry no readable year. No dated changelog (10). No public changelog. Support is by email, with Slack on Growth and above. GitHub issues weren't read, since GitHub's pages and API answer 403 in our session (5). Official SDKs for TypeScript and Python are current at 1.0. The MCP servers were not found in the MCP registry, per the 8 October check (15). The SDK repositories have CI and publish workflows whose results we did not read, and the self-hosted MCP server's last commit is 24 July 2025 (7). 20 + 10 + 5 + 15 + 7 = 57.

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.

Anchor Browser 54

API keys in the anchor-api-key header, per project. The MCP servers also accept OAuth through signin.anchorbrowser.io with mcp:tools and mcp:admin scopes. No key scopes, expiry or rotation guidance were found in the docs (22). The documented CDP connection passes the key as apiKey in the wss://connect.anchorbrowser.io URL, a secret in a query string (minus 10). No read-only API key. Live view has a read-only mode, volumes mount read-only, secrets can be limited to matching domains, identities sign in without returning credentials, and tasks can pause for a person's input (13). No prompt-injection guidance was found in the docs. Secret values and sensitive data masking keep credentials out of the model's view, which is a partial mitigation (4). Recordings, session history, webhook delivery logs and a billing endpoint give the operator a trail. The audit logs on the security page are restricted to Anchor's staff (11). SOC 2 Type 2, ISO 27001 and HIPAA per the security page and trust portal, with reports behind an access request, and a disclosure contact in the SDK's SECURITY.md. No security.txt (404 again on 1 November) or bug bounty was found (14). The documented CDP URL still carries apiKey on 1 November. 22 - 10 + 13 + 4 + 11 + 14 = 54.

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.

Anchor Browser 77

Graded as a hosted service. status.anchorbrowser.io runs on incident.io with two components, Website and Anchor Application (20). Both show operational on 1 November, and the RSS feed is still empty. The page has recorded no incident since it was set up in June 2025. This run reads a readable page that has never posted an incident as a clean record at 20, as for quicken-simplifi, outline and linkup, where the 8 October check gave 25, a value the checklist doesn't name (20). Limits are published, 5, 25 and 100 session creations a minute and 5, 25 and 200 concurrent browsers by plan, and 2,000 requests a minute on Web Unlocker (15). The OpenAPI document declares 429 on ten operations, with RateLimit and Retry-After headers on session creation, and the Web Unlocker docs say to retry 429, 500, 503 and 504 with exponential backoff. The sessions guide now says a 429 from the per-minute limiter comes before a session exists, so retrying it doesn't create a second one, that the API reads no Idempotency-Key, so retrying a 5xx or 409 can, and which statuses are terminal. Safe-retry guidance without idempotency keys, read as e2b's (12). No SLA was found on the pricing page, the docs or the site (0). The API is version 1.0.0, the SDKs are 1.0 and nothing marks the sessions API as beta (10). 20 + 20 + 15 + 12 + 0 + 10 = 77.

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.

Anchor Browser 80

OpenAPI 3.1.0 at docs.anchorbrowser.io/openapi.yaml with 101 paths and 136 operations, unchanged on 1 November, and the anchor-api-key header scheme (25). llms.txt, llms-full.txt and a Markdown twin of every docs page (10). All 136 operations carry a description, the spec's introduction says which resource suits which job, and a docs page compares the task types. Few descriptions say when not to use an endpoint (16). Inputs are typed with 90 enum declarations and named request schemas. We did not audit every field for bounds (11). The spec holds 121 examples and declares 400, 401, 404 and 500 widely, with one shared error schema of code and message (12). Paths are versioned under /v1 and a legacy spec is kept. No API changelog was found, docs.anchorbrowser.io/changelog still returns 404 on 1 November, and the SDK changelog stops at 1.0.0-dev.4 (6). 25 + 10 + 16 + 11 + 12 + 6 = 80.

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.

Anchor Browser 73

The main MCP server lists about 24 tools and reaches the other REST routes through list_endpoints, get_endpoint and two call tools. Browser control and per-site actions are separate servers, and the docs warn that /v1/mcp/actions without a domain lists thousands of tools. 15 for the tool count plus 5 for the split servers (20). Session lists take page, limit, sort, search and filters by status, tag, domain and date, volumes use a cursor, and webhook deliveries take limit and offset (17). Errors return an integer code and a message, 402 marks exhausted credits, and Agent Access errors name the next call. No stable machine-readable error codes were found (13). No idempotency keys. The MCP server splits call_endpoint_read from call_endpoint_write, and batch sessions have a retry-failed call. Tool annotations were not read because the server needs a key (8). A session starts from an empty body, and the SDKs cover TypeScript and Python (15). 20 + 17 + 13 + 8 + 15 = 73.

Kernel 84

Graded mainly on the API, with the MCP server noted. Responses are scoped per resource and the MCP server groups actions into about 32 tools (18). List endpoints page with limit and offset and filter by status (18). Typed SDK errors and documented 409 on concurrent changes, 204 on a pool timeout and 429 (17). Retrying an MPP purchase with the same credential returns the same browser, and the MCP tools carry readOnlyHint where read-only (16). SDKs in TypeScript, Python and Go plus a CLI, with defaults such as a 60-second timeout (15). 18 + 18 + 17 + 16 + 15 = 84.