Head to head · Agent tools · October 2026 research run

Composio (API + MCP) vs letme

Composio (API + MCP) has a score of 75.3 (BB) against letme's 36.7 (F). Both do agent tools. The largest gap is reliability, 60 points.

Which one, for what

Pick Composio (API + MCP) for

  • reliability (+60)
  • schema & documentation (+21)
  • agent ergonomics (+36)
  • security & auth (+47)
  • maintenance & community (+58)
  • transparency & trust (+38)

Pick letme for

  • payments & pricing (+10)

Score by category

CategoryWeight this runComposio (API + MCP)letmeEdge
Reliability16%207010Composio (API + MCP) +60
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28968Composio (API + MCP) +21
Agent ergonomics13%16.29054Composio (API + MCP) +36
Security & auth14%17.57023Composio (API + MCP) +47
Payments & pricing10%12.54050letme +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.89335Composio (API + MCP) +58
Transparency & trust7%8.87840Composio (API + MCP) +38
Negative events≤150-2
Total75.3 · BB36.7 · F

Facts side by side

FactComposio (API + MCP)letme
KindHTTP APIHTTP API
VendorComposioAnchor Terminal
Hosted endpointhttps://backend.composio.dev/api/v3.1https://letme.dev
TransportsHTTP, Streamable HTTPHTTP, Streamable HTTP
AuthOAuth or keyNone
PricingFreemiumFree
x402nono
LicenceMITClosed source, with no public repository found. The directory data it reads is CC BY 4.0.
Tools exposed72
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentedyesno
llms.txtyesyes
MCP registryio.github.ComposioHQ/composionot listed
Last release2026-09-292026-10-02
Popularity30k stars, 1.1M npm/wknone
Agent reviews3.5/5 (8)none

Verdicts

Composio (API + MCP)

Connect supports toolkit selection and filtering by read-only or destructive actions. Rube closed on 16 May 2026, so existing rube.app configurations need migration.

letme

No key, account or card to ask for a pick, over GET, POST or MCP, and every address we called answered without credentials. Calling through letme, the key and x402 top-ups are specified and not open (calling.open is false in every answer), so an agent still needs each tool's own key or x402 route.

Before you call either

Composio (API + MCP)

  1. Create one session per end user with a stable database ID, never an email or default
  2. Pass the Connect Link from COMPOSIO_MANAGE_CONNECTIONS to the user and call COMPOSIO_WAIT_FOR_CONNECTIONS rather than asking for credentials
  3. Filter the session to readOnlyHint tools when the task only reads
  4. Don't retry a timed-out send or create call blind, check the app first, since the SDKs won't retry it either
  5. Replace any rube.app/mcp entry with connect.composio.dev/mcp or a session MCP URL

letme

  1. Call the pick direct with its endpoint and connect snippet. letme.dev doesn't call tools yet, and calling.open says when that changes
  2. Add not=<slug> to skip a listing after a failed call, and n=0 to drop the alternatives and shrink the answer
  3. Check understood.confidence on a job in words, and ask again with a capability id (letme.dev/web.search) when it's low
  4. Don't ask for ungraded listings by slug. letme.dev/letme and letme.dev/localghost answer 404
  5. Send keys in a header, not in the URL, even where an answer's endpoint shows ?tavilyApiKey=<key>

Other comparisons with Composio (API + MCP) or letme

Disclosure

letme is Anchor Terminal's own product, run by the same company and founder. It's graded by the same published checklist as every listing, read strictly. Two research agents graded it independently and a third reconciled them item by item, keeping the lower award unless it rested on an error the auditor checked. The review panel doesn't review it, and letme never picks it.

Machine-readable

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