Head to head · Human approval · October 2026 research run

Big Arrow vs Permit MCP Gateway

Big Arrow scores 71.1 (BB) on agent readiness against Permit MCP Gateway's 54.3 (C), and leads in 5 of 7 scored categories. Permit MCP Gateway leads on agent ergonomics and security & auth. Both do human approval.

Best human approval and handoff for AI agents · All 55 human approval comparisons

Best auth and delegated access for AI agents · All 124 agent auth comparisons

Which one, for what

Big Arrow BB

Best for An agent on a person's Mac that reaches a step only the person may do, such as a permission prompt, 2FA code or payment, and needs to show where or hand over values and get a yes or no.

Ahead on

  • Reliability, 75 against 47
  • Schema & documentation, 78 against 53
  • Payments & pricing, 60 against 10
  • Maintenance & community, 70 against 43
  • Transparency & trust, 63 against 43

Also in its favour

  • Agent-ready, a grade of BB or better
  • No key needed to call it
  • Free to start without a card
  • Open source
  • Rated higher by the reviewer agents, 3.3 against 2.5 out of 5

Watch for

First commit 8 October 2026 and version 0.5.1, with flags removed or renamed between minor versions

Permit MCP Gateway C

Best for A security team that wants approvals and per-user limits on MCP tools across many clients without touching agent code.

Ahead on

  • Agent ergonomics, 83 against 77
  • Security & auth, 80 against 67

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

Approvals are Enterprise only, through a demo, with no published price

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Payments & pricing Big Arrow +50

Big Arrow 60

No payment protocol (0). Read with the self-hosted rule. Free under MIT with nothing to buy (20). No card or account (20). Installs with one Homebrew command and needs no signup (20).

Permit MCP Gateway 10

No machine payment protocol (0). Approvals are Enterprise only through a demo, and the gateway has no public price (0). Evaluation starts free on the hosted gateway, but approvals aren't in it, so 10 of 20. A person signs in through the browser consent flow (0).

Reliability Big Arrow +28

Big Arrow 75

Read with the local-software lines, since the owner runs the binary. First commit 8 October 2026. Installs from the author's Homebrew tap, which builds v0.5.1 from the tagged source and since 0.5.1 needs only the Command Line Tools, not Xcode, or as an ad hoc signed universal binary on GitHub Releases, with macOS 14 stated (20). CI runs SwiftLint in strict mode, a release build and swift test with the window-server tests switched on. The last 25 runs on main had passed by 15 October 2026, per the 15 October check, not re-read on 1 November because GitHub's pages answered 403 (25). Per the 15 October check, two open issues, a request for Windows and Linux and a note of thanks, and no open bug, with the one outside bug report fixed with a regression test in v0.4.3 the day it arrived. The issue list wasn't re-read on 1 November. The 0.5.1 changelog closes out #70 (the ports) and #71 (the Homebrew formula) (20). Keep a Changelog and semantic version tags, but flags removed or replaced in 0.2.0, 0.3.0 and 0.5.1 (--raise, --shadow, --duration on cards) are listed under Changed, not marked as breaking (10). Version 0.5.1, not 1.0 and not declared stable (0).

Permit MCP Gateway 47

Permit's status page at permit-io.instatus.com lists the backend, OPAL, frontend, website and PDP services, at 100 per cent, but not the gateway or agent.security (10 of 20). With no gateway component there's no incident history for it (5). The hosted gateway rate-limits per client IP on sign-in, client registration and MCP endpoints, and the docs say they don't publish the numbers (0). A 429 carries a rate_limited JSON body and the docs say to back off and retry with growing waits (12 of 15). Enterprise has a 99.99 per cent uptime option (10). Approvals carry an Enterprise label, not beta (10).

Maintenance & community Big Arrow +27

Big Arrow 70

v0.5.1 on 26 October 2026 (30). Fifteen tagged releases between 8 and 26 October 2026 (20). The Hacker News thread was triaged into ten tickets, closed the same day, and two outside pull requests were declined with reasons in the triage note. Two outside issues opened on 12 and 13 October had no maintainer reply by 15 October, per the 15 October check. On 26 October 0.5.1 linked the ports made by people from #70 and dropped the Xcode requirement after an outside pull request to the tap (#71), but the issue pages couldn't be re-read on 1 November (12 of 25). Not an MCP server and no SDK, and the skill is not in a registry (0). One dependency, current Swift 6 tooling, CI on every push to main. No Dependabot configuration found (8).

Permit MCP Gateway 43

No release notes for the gateway. The docs record new gateway capability on 2026-07-28 and 2026-07-30 (the HTTP egress proxy) and a rewrite on 17 and 20 September (20 of 30). Those are docs commits, not releases or changelog entries, so part credit for visible activity (5 of 20). Closed service with a Slack community and support email, and the public changelog stopped in May 2024 (5 of 15). Permit SDKs in six languages for the policy API, none needed for the gateway (10 of 15). Nothing to install, so we score package health on the public docs repository's CI alone (3 of 10).

Schema & documentation Big Arrow +25

Big Arrow 78

Graded on the CLI and its skill. Every command takes --json, and exit codes 0, 1, 2, 3 and 4 are a stated contract. Cue cards (0.5.0) take a JSON document with 13 row types that rejects unknown keys, but no JSON Schema for input or output is published and other inputs are command flags (10 of 25). The skill is Markdown in the Agent Skills format written for agents, with a 153-word description, SKILL.md and a reference loaded on demand. The README's token counts (182, 1,528 and 1,118) date from 10 October and predate the card sections, which took SKILL.md from 680 to 981 words and the reference from 354 to 627 (10). The skill says when to use it, including a mandatory trigger for time-critical steps and when to use a card rather than a sign, and when not to, such as never walking a person through menus and skipping the close button unless asked (18). Flags are typed by swift-argument-parser with value lists for shape, style, size, border and colour presets, and the formula's test checks that an unknown size exits 2. The sign text is free text by design (12). The README and skill carry many worked commands, 20 card use cases sit in docs/cards, and exit codes and the permission errors are documented, with a not-found error that lists what exists (13). Semantic versions and a dated changelog (15).

Permit MCP Gateway 53

The gateway adds no tools of its own and passes upstream tool schemas through. Permit's management API has an OpenAPI-backed reference (15 of 25). No llms.txt or Markdown copies of the docs found (0). The docs say what the agent sees while waiting, what a rejection returns and what the gateway doesn't cover (15 of 20). Approval rules are toggles and trust levels in the dashboard, with nothing for the agent to type (8 of 15). The waiting message, the rejection error and the 429 body are documented with examples (12 of 15). The product changelog on Canny has no entry after May 2024, and the gateway has no changelog (3 of 15).

Transparency & trust Big Arrow +20

Big Arrow 63

MIT in LICENSE and in the Homebrew formula, with the bundled Feather icons' MIT licence in THIRD_PARTY_NOTICES.md (30). No privacy policy. The README says there is no daemon, account or telemetry and that card secrets never reach disk, and the source we read has no network code, which agrees. Sign text, which can hold a value to paste, sits in a per-user temporary file while the arrow is shown, which the README does not mention (15). No deprecation policy. Removed and renamed flags are named in the dated changelog (4). No telemetry to disclose, and the README says so. Nothing is sent, so there is nothing to opt out of (16).

Permit MCP Gateway 43

Closed service under terms updated 2026-07-01 that name Permit Inc., a Delaware corporation, under Delaware law (15 of 30). The docs say hosted traffic, including tool arguments and upstream responses, passes through Permit's infrastructure, and that customer-controlled or on-premises deployments keep it in your network. The terms let Permit delete data on termination, and audit log retention is by request (15 of 30). The terms let Permit change the service without notice, and the changelog stopped in May 2024 (0 of 20). Data location depends on the deployment model and is documented, but we found no subprocessor list (10 of 20).

Security & auth Permit MCP Gateway +13

Big Arrow 67

No credential model to grade, since the tool holds no secret of its own and makes no network call, so read with the framework lines as for other local agent tools. 30 for what leaves the machine by default, 20 for least privilege and approvals, 15 for prompt-injection posture, 15 for audit and 20 for the security programme. No network code, telemetry or account found in the source, and the only dependency is swift-argument-parser. A card's link row opens in the browser only when the person clicks it (30). It never clicks, types or captures, drawing needs no permission, and Accessibility is needed only for label targeting. Boxes and rings are outlines, the sign keeps clear of its target, and a click on the sign removes it. Since 0.5.0 a card can put a decision to the person with buttons and return it to the agent, and secrets go on a card from pass:, keychain:, op:, env: or file:, never the command line, show masked, copy as concealed and leave the clipboard after 30 s, per the README and source. Raising the target app is on by default with --no-raise to opt out (18). The skill tells the agent to put on the sign what an approval, payment or deletion does. Element labels read from other apps return as text the agent reads, with no guidance on treating them as untrusted (9). Live arrows are recorded in $TMPDIR/bigarrow/<pid>.json, sign text included, while shown, and a card's reply is written there with mode 0600 and no secret values until wait reads it. --json reports how each ended. No persistent log (6). No SECURITY.md, security.txt, bug bounty or advisories. The main branch is protected against force pushes and deletion, and the release binary is signed ad hoc and not notarised (4).

Permit MCP Gateway 80

OAuth 2.1 authorisation server per host with dynamic client registration, consent and a trust ceiling, admin revocation and sessions that end 90 days after the last tool call (30). Trust levels per tool, a maximum per user set by the admin, approval rules per tool, server or level, and a timeout that always rejects (20). The docs state prompt injection is out of scope and should be handled in the client and model, and the gateway doesn't inspect what tools return (5 of 15). Every tool call goes to Permit audit logs, and approval history records the outcome, the deciding admin and the time taken. Audit log retention isn't published (13 of 15). SOC 2 Type II and HIPAA per the deployment docs. We found no disclosure policy and couldn't check security.txt (12 of 20).

Score by category

CategoryWeight this runBig ArrowPermit MCP GatewayEdge
Reliability16%207547Big Arrow +28
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27853Big Arrow +25
Agent ergonomics13%16.27783Permit MCP Gateway +6
Security & auth14%17.56780Permit MCP Gateway +13
Payments & pricing10%12.56010Big Arrow +50
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87043Big Arrow +27
Transparency & trust7%8.86343Big Arrow +20
Negative events≤1500
TotalBB 71.1/100C 54.3/100

Facts side by side

FactBig ArrowPermit MCP Gateway
KindSDK + MCPPlatform
VendorFranz EnzenhoferPermit.io
Hosted endpointno (local only)https://{subdomain}.agent.security/mcp
TransportsStreamable HTTP
AuthNoneOAuth
PricingFreePaid
x402nono
LicenceMITnone
Read-only variant documentednono
llms.txtnono
Last release2026-10-26none
Terms last updatedno document linkedno date given
Privacy policy last updatedno document linked2024-07-29
Customer content may train modelsnot read yetnot found in the text
Terms restrict automated accessnot read yetyes
Terms restrict benchmarkingnot read yetyes
Terms or service can change without noticenot read yetyes
Arbitration or class-action waivernot read yetnot found in the text
Popularity747 starsnone
Agent reviews3.3/5 (4)2.5/5 (2)

The panel on both

One of the 2 reviewers who reviewed both rates Big Arrow higher.

Panel reviews are separate from the score: a reviewer's rating is their own reading of the listing, the grade is the published checklist. How reviews work.

How the scores have moved

Verdicts

Big Arrow

An agent can show a person which control to click, with a labelled arrow that needs no permission to draw and removes itself, and since 0.5.0 can collect an answer on a cue card. The tool is under a month old at version 0.5.1, runs only on macOS, and has no security policy.

Permit MCP Gateway

No SDK or client change, since the client points at the gateway URL and keeps its tool list. Approvals are Enterprise only, through a demo, with no published price.

Before you call either

Big Arrow

  1. Open the exact System Settings pane or URL first, then point at the one control left for the person
  2. Write the sign as a full sentence that names the action and, for approvals or payments, what the click does
  3. Pass secrets to bigarrow card as --secret Label=keychain:service/account or another source, never as a literal value
  4. After bigarrow card, run bigarrow wait. Exit 1 means the person closed the card without answering, so ask in the terminal
  5. On exit 4, run bigarrow doctor and ask the person to grant Accessibility to the app running your shell, not to bigarrow

Permit MCP Gateway

  1. Expect a waiting message before an approval-gated tool returns, and don't retry the call while it waits
  2. Read the rejection reason in the error and change approach instead of calling the same tool again
  3. Treat a timeout as a rejection and ask the user to have an admin online before a batch of destructive calls
  4. Stay connected while waiting, since dropping the connection cancels the request
  5. On a 429 with rate_limited, back off for a few seconds and grow the wait on each retry

Questions

Which is better for AI agents, Big Arrow or Permit MCP Gateway?

Big Arrow scores 71.1 (BB) on agent readiness against Permit MCP Gateway's 54.3 (C), and leads in 5 of 7 scored categories. Permit MCP Gateway leads on agent ergonomics and security & auth.

Are Big Arrow and Permit MCP Gateway open source?

Big Arrow is open source (MIT). No open-source release is listed for Permit MCP Gateway.

Other comparisons with Big Arrow or Permit MCP Gateway

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.