Install Jentic One Beta

Connect the Mermail Agent Marketplace to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Mermail Agent Marketplace, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.

Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.

Step 1: Jentic One Host machine

# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fmermail.app%2Fmermail" | sh

Step 2: Agent machine

# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fmermail.app%2Fmermail" | sh
jentic register       # connects your agent to your Jentic One instance

Jentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.

Capabilities

What an agent can do with Mermail Agent Marketplace API.

Create a hosted agent inbox, optionally choosing the Mermail address and name

List and search inbox messages by query, from, to, subject, date range, or folder

Require scan_status clean through require_scan_status before an agent reads message bodies

Read a single message, its full thread, its safe context, or a downloaded attachment

GET STARTED

Start building with Mermail Agent Marketplace API

Explore with Jentic One

View OpenAPI Document

Use Cases

Patterns agents use Mermail Agent Marketplace API for, with concrete tasks.

★ An agent with its own inbox, connected through Jentic

Agents that sign up for services or talk to people by email need an address of their own. Through Jentic the agent finds the Mermail create-mailbox operation, gets a hosted inbox, and then lists and searches it for replies. Because Mermail puts the mailbox id in the URL path, your Jentic One rules can hold the agent to that one inbox and to the operations you choose.

POST /api/agent/v1/mailboxes with name 'research-agent', store the returned mailboxId, then GET /api/agent/v1/mailboxes/{mailboxId}/emails with require_scan_status 'clean'

Catching verification and sign-up emails

When an agent registers for a service, the confirmation link arrives by email. The search operation filters by from, subject, and a date_start and date_end window, and the agent_safe_content and require_scan_status parameters keep unscanned bodies away from the model. Reading the message or its context returns the content only when the scan is clean.

GET /api/agent/v1/mailboxes/{mailboxId}/search with from 'no-reply@example.com', subject 'Confirm', and require_scan_status 'clean', then GET the matching message by emailId

Human-approved replies with drafts

For outbound mail you want to check first, the agent saves a draft with a body and optional thread_id or in_reply_to, and sends only after review. Sending, replying, and forwarding each require to, from, and subject and cost $0.01 per call, while drafts are a $0 handshake.

POST /api/agent/v1/mailboxes/{mailboxId}/drafts with body 'Thanks, confirmed for Tuesday.' and thread_id from the original message

Forwarding receipts and attachments

An agent that receives receipts or reports can download an attachment by attachmentId or forward the whole message to another address, keeping the thread history with in_reply_to and references.

POST /api/agent/v1/mailboxes/{mailboxId}/emails/{emailId}/forward with to 'accounts@example.com', from the mailbox address, and subject 'Fwd: Invoice 1042'

Key Endpoints

16 endpoints — the mermail api gives an ai agent its own hosted email inbox, bound to a crypto wallet instead of an api key.

METHOD

PATH

DESCRIPTION

POST

/api/agent/v1/mailboxes

Create a hosted agent inbox

GET

/api/agent/v1/mailboxes/{mailboxId}/emails

List inbox messages

GET

/api/agent/v1/mailboxes/{mailboxId}/search

Search inbox messages

POST

/api/agent/v1/mailboxes/{mailboxId}/emails

Send an email

POST

/api/agent/v1/mailboxes/{mailboxId}/emails/{emailId}/reply

Reply to an email

GET

/api/agent/v1/mailboxes/{mailboxId}/threads/{threadId}

Get a message thread

POST

/api/agent/v1/mailboxes/{mailboxId}/drafts

Save a draft

POST

/api/agent/v1/mailboxes

Create a hosted agent inbox

GET

/api/agent/v1/mailboxes/{mailboxId}/emails

List inbox messages

GET

/api/agent/v1/mailboxes/{mailboxId}/search

Search inbox messages

POST

/api/agent/v1/mailboxes/{mailboxId}/emails

Send an email

POST

/api/agent/v1/mailboxes/{mailboxId}/emails/{emailId}/reply

Reply to an email

GET

/api/agent/v1/mailboxes/{mailboxId}/threads/{threadId}

Get a message thread

POST

/api/agent/v1/mailboxes/{mailboxId}/drafts

Save a draft

Why Jentic?

What agents get from Jentic-routed access to this vendor.

Setup

Wiring Mermail by hand means handling its 402 challenge, attaching an x402 PAYMENT-SIGNATURE or MPP Payment-Authorization header, and replaying uncertain paid calls with the same Idempotency-Key. Through Jentic you install once, import Mermail from the API Directory, and your agent calls it with the operation schemas in hand.

Permission scoping

Mermail puts the mailbox id in the URL path (/api/agent/v1/mailboxes/{mailboxId}/...), so a rule can pin your agent to one inbox and the operations you pick. You choose the operations it may call, so paid ones like send, reply, forward, or mailbox creation are not included unless you add them.

Credential isolation

Mermail declares no API key or token: paid routes are authorised per request by an x402 payment signature, so there is no long-lived secret for the agent to hold. Calls still run through your own Jentic One instance, where your rules and logs apply.

Intent-based discovery

Agents search Jentic by intent such as 'search my agent inbox' or 'reply to an email', and Jentic returns the matching Mermail operation with its input schema so the agent calls the right endpoint without browsing the reference docs.

FAQs

Specific to using Mermail Agent Marketplace API through Jentic.

What authentication does the Mermail API use?

The Mermail agent API declares no API key or token in its OpenAPI spec. Payment is the credential: an unpaid call returns 402, and the agent retries with an x402 payment or identity-handshake value in the PAYMENT-SIGNATURE header, or an MPP value in Payment-Authorization on paid writes when that is enabled. Reads and drafts are $0 handshakes that bind the wallet; the spec notes that the older workspace API at /api/v1 still uses x-api-key.

How much does the Mermail API cost per call?

Per the spec, creating a mailbox costs $2, and sending, replying, and forwarding cost $0.01 each, paid in USDC. Listing, reading, searching, folders, labels, and drafts are $0 identity handshakes. The live 402 challenge is the authoritative quote.

How do I create an agent inbox through Jentic?

Install Jentic One with `curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh` and import the Mermail API from the directory. Your agent searches 'create an email inbox for my agent', gets POST /api/agent/v1/mailboxes with its schema, and sends an optional email and name; the payment header is part of the call. To run it on your own infrastructure, install Jentic One from its GitHub repo.

Can I limit what my agent is allowed to do with the Mermail API?

Yes. For example, write a rule that allows only the list, search, and get-message operations under /api/agent/v1/mailboxes/mbx_123, so the agent can read that one inbox but cannot send, reply, forward, or create new paid mailboxes. Add the send operation when you are ready, and every call it makes is logged.

Is there a Mermail MCP server?

You don't need an MCP server to give your agent Mermail. Jentic connects it directly from the API Directory: import it and your agent calls it, discovering operations on demand instead of loading extra tool definitions into its context.

What are the rate limits for the Mermail API?

The OpenAPI spec does not specify rate limits. Check the Mermail documentation at https://mermail.app for current limits.

How does Mermail keep unsafe email content away from my agent?

Inbound messages are scanned. The list and search operations accept require_scan_status (clean, flagged, or skipped) and agent_safe_content, and the get, context, and attachment operations return metadata with content_omitted when a body is not clean. The spec advises requiring scan_status clean before using body content.

Mermail App Mermail Agent Marketplace

AI ReadinessFoundational (C+)58/100

See full scorecard

Official vendor OpenAPI document · agent-readyCommunicationsEmail Deliverynone (x402 payment)16 EndpointsREST

For Agents

Create a wallet-bound email inbox for an agent, then read, search, send, reply to, and forward mail from it, paying per call over x402 instead of using an API key.

Use for: I need an email address my agent can receive verification codes at, Search my agent inbox for messages from billing@example.com, Reply to the latest email in this thread, Forward the invoice email to my accountant

Not supported: Does not send bulk marketing campaigns, manage your own domain's DNS, or deliver SMS. Use for wallet-bound hosted agent inboxes only.

The Mermail API gives an AI agent its own hosted email inbox, bound to a crypto wallet instead of an API key. An agent creates a mailbox, lists and searches its messages, reads threads and attachments, saves drafts, and sends, replies to, or forwards email. Payment is the credential: unpaid calls return 402, reads and drafts are $0 identity handshakes over x402, sending costs $0.01, and creating an inbox costs $2 in USDC. Inbound bodies are scan-gated, so non-clean messages come back as metadata with content_omitted.

Jentic One on Github View OpenAPI Document

Show dimension breakdown

Foundational Compliance

Base layer of spec validity and structural soundness.

Grade: ASignals: 4

97%

Lint Results

Aggregated quality score from linter diagnostics, weighted by severity.

100%

Resolution Completeness

Percentage of `$ref` references that resolve successfully.

100%

Specification Validity

Checks whether the API description parses successfully and conforms to its declared specification (e.g., OpenAPI).

25%

Structural Integrity

Structural correctness score based on schema issues using logarithmic dampening.

Developer Experience & Jentic Compatibility

Clarity, completeness, and ingestion readiness for developers and tooling.

Grade: B-Signals: 4

Example Density

How richly the API is illustrated with examples.

100%

Example Validity

Percentage of examples that conform to their schemas.

50%

Response Coverage

Percentage of operations with complete response definitions (success, client error, server error).

100%

Tooling Readiness

Health of API ingestion, bundling, and resolution within Jentic pipelines.

AI-Readiness & Agent Experience

Semantic breadth, depth, and agent comprehension for AI systems.

Grade: DSignals: 4

23%

Description Coverage

Coverage of descriptions across API elements.

Error Standardization

Coverage of RFC 9457 Problem Details for error responses.

100%

OperationId Quality

Coverage, uniqueness, and casing consistency of operationIds for AI inference.

52%

Summary Coverage

Coverage of summaries across operations/tags/info.

Agent Usability

Functional utility, complexity comfort, and AI orchestration readiness.

Grade: A+Signals: 1

94%

Complexity Comfort

Agent comfort level based on API operational and structural complexity.

100

Security

Trust, risk posture, and security compliance.

Grade: A+Signals: 1

100%

Authentication Strength

Average quality of security schemes based on authentication method strength (weakest link for OAuth2).

AI Discoverability

Findability, semantic richness, and reasoning readiness.

Grade: FSignals: 1

28%

Descriptive Richness

Clarity and depth of descriptions across API elements.

Connect the Mermail Agent Marketplace to your agent

Capabilities

Start building with Mermail Agent Marketplace API

Use Cases

Key Endpoints

Why Jentic?

Related APIs

FAQs

Mermail App Mermail Agent Marketplace

Jentic AI Readiness Score

Mermail Agent Marketplace

Foundational Compliance

Lint Results

Resolution Completeness

Specification Validity

Structural Integrity

Developer Experience & Jentic Compatibility

Example Density

Example Validity

Response Coverage

Tooling Readiness

AI-Readiness & Agent Experience

Description Coverage

Error Standardization

OperationId Quality

Summary Coverage

Agent Usability

Complexity Comfort

Security

Authentication Strength

AI Discoverability

Descriptive Richness