Prototype · Preview: every server in the official registry, synced every 30 minutes. Reviews and accounts come in a later step.
PopNx MCPMCP servers for people who use AI · explained in plain words

AI SENSE Free Public Tools

by aisenseapiversion 1.18.0i★ –iRuns in the cloud
Registry namecom.aisenseapi/free-public-tools

Install

Overview

Description from the maker (original English)

79 public tools: agent workflows, audio data transfer, semantic search, queues and webhooks.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

  • Connection: Runs in the cloud
  • Transport: Streamable HTTP
  • Category: Design, images & audio

Install

Pick the AI app you use, then copy the settings.

Before you install

You need

Which app do you use?

Pick your app above. We remember it, so next time the button says “Install in …”.

Works in Claude on the web, desktop and mobile:

  1. Open Settings → Connectors
  2. Press Add custom connector
  3. Paste the address below and press Add
  4. If it asks you to sign in, sign in with the maker
SettingsConnectors1+ Add2https://…3
https://aisenseapi.com/mcp

Run this in your terminal

claude mcp add --transport http free-public-tools https://aisenseapi.com/mcp

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "free-public-tools": {
      "url": "https://aisenseapi.com/mcp"
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "free-public-tools": {
      "type": "http",
      "url": "https://aisenseapi.com/mcp"
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

ChatGPT connects only to servers on the internet:

  1. Open ChatGPT on the web → Settings → Connectors (Apps)
  2. Press Create or Add (some plans need Developer mode under Advanced first)
  3. Paste the address below, give it a name and save
  4. If it asks you to sign in, sign in with the maker
SettingsConnectors1+ Create2https://…3
https://aisenseapi.com/mcp

Menu names can differ slightly by plan and over time.

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Tool names and descriptions exactly as the server reported them on Nov 6, 2026. The maker wrote them, not us; we show them as plain text.

  • get_current_time

    Get the true current date and time, as an ISO 8601 string and a Unix timestamp, for any timezone. Use this whenever the actual present moment matters - stamping a record, computing an age or a deadline, deciding whether something has expired - because a language model has no cloc

  • generate_uuid

    Generate one random RFC 4122 version 4 UUID. Use it when you need an identifier that will not collide with anything else - an idempotency key, a correlation id across systems, a filename - rather than inventing a string yourself, which is not random and tends to repeat across run

  • shorten_url

    Turn a long URL into a short 307.fi link that redirects to it. Use it when a URL has to be typed, read aloud, pasted into a message with a length limit, or put in front of a person. No API key, no account and no sign up. The link stops working 24 hours after creation, so do not u

  • store_temporary_data

    Put any JSON value somewhere another process can fetch it, and get back a storage_id plus a public read_url. Use it to hand a result to a different agent, a script, a webhook receiver or a later run, when there is no shared filesystem and no database between you. No API key, no a

  • read_temporary_data

    Fetch back a JSON value that store_temporary_data saved earlier, in this session or in another one. Returns the value exactly as it was stored. Fails if the id is unknown or if the 24 hour lifetime has already passed, so treat a failure as expired or never written rather than as

  • create_webhook_capture

    Create a throwaway URL that records the next HTTP request anyone sends to it, headers and body included. Use it to see what a webhook provider, a form or a third party service actually transmits, instead of trusting their documentation, and to prove that an integration fired at a

  • read_webhook_capture

    Check whether anything has been sent to a capture URL yet, and read it. The status field is pending or captured. Pending is the ordinary answer before the sender fires and is not a failure. Set wait_seconds from 1 to 25 to wait efficiently for the first request. The call returns

  • create_human_approval

    Put a decision in front of one to twenty people. Use one respondent for a normal approval, or several when every invited person should answer through a separate bearer form link. Group results contain counts, a tally and anonymous numbered responses. Optional notify_url receives

  • read_human_approval

    Check whether the person has answered a form from create_human_approval, and read the answer. For a group, partial means at least one person has answered and answered means all form links are complete. The group view contains counts, a tally and anonymous respondent numbers, neve

  • create_agent_wake

    Create a durable MCP task that completes when a webhook arrives, a person answers a form or a chosen time is reached. Use it when an agent must pause and continue after an outside event without holding one HTTP request open. The task lasts from 60 seconds to 24 hours. Webhook bod

  • create_heartbeat

    Create a deadline monitor for a job, device or agent that should keep checking in. Call ping_heartbeat before the expected interval plus grace period ends. One missed deadline calls a public HTTP or HTTPS webhook or wakes an active Agent Wake webhook task. The monitor lasts at mo

  • read_heartbeat

    Read one heartbeat immediately. Use it to inspect whether the monitor is armed, missed, fired or expired, whether it is running late, and its next deadline. This does not wait for a state change. The heartbeat ID is a 256-bit bearer secret. No authentication is required.

  • ping_heartbeat

    Record a check-in for an armed heartbeat and move its next expected deadline. Use it after successful work or from a liveness loop. A ping does not extend the absolute 24 hour lifetime. The heartbeat ID is a bearer secret. No authentication is required.

  • create_lease_namespace

    Create a random private namespace before several agents coordinate work using short readable keys. The namespace is a bearer secret and is returned once. Share it only with the cooperating agents. This operation stores no lease and needs no authentication.

  • acquire_lease

    Claim one unit of work so concurrent agents do not perform it twice. The first writer receives an owner token and a monotonic fencing token. A later caller receives held, conflict or a reusable completed result. Contention is a normal result. Use a private namespace, or supply a

  • renew_lease

    Extend a lease that this caller still owns. Use it before the current TTL ends when work is still running. The owner token is required and must stay secret. Renewal cannot move the absolute 24 hour limit. No authentication is required.

  • release_lease

    Give up a lease before its TTL ends so another agent can acquire the work. Use it when abandoning work without a reusable result. The secret owner token is required. No authentication is required.

  • complete_lease

    Finish owned work and save a reusable JSON result for later callers with the same identity and fingerprint. The result is limited to 32 KB and secret-shaped fields are redacted. Do not store secrets or personal data. The owner token is required. No authentication is required.

  • create_agent_inbox

    Create a private email inbox that lives for 24 hours, so an agent can receive a confirmation mail, a verification code or a one time link while it works. The call returns two identifiers and they are not interchangeable. The address is public by construction: it travels in mail h

  • read_agent_inbox

    Read the mail that has arrived in an inbox from create_agent_inbox. Each message carries the sender, the subject, the arrival time in UTC, the cleaned text, any standalone 4 to 8 digit codes found in that text and any public http or https links. Attachments and raw headers are no

  • create_agent_queue

    Create a small temporary pull queue for cooperating agents. Its fixed 24 hour lifetime cannot be extended. Returns separate read, write and worker bearer tokens once. Keep them secret and share only the role needed. Maximum 100 jobs over the queue lifetime, 16 KiB per JSON payloa

  • read_agent_queue

    Read queue metadata and pending, claimed, completed and failed counts using the read token. Does not list payloads, disclose role tokens or extend the fixed expiry.

  • enqueue_agent_queue_job

    Add a JSON job using the write token and a stable job_key. The same key and payload return the original job. Changing the payload for that key is a conflict. Payloads are limited to 16 KiB encoded JSON and must contain no secrets or personal data. The 100-job lifetime limit inclu

  • read_agent_queue_job

    Read one known job, its JSON payload and status using the read token. The active claim receipt and role tokens are never returned by this operation.

  • claim_agent_queue_job

    Claim the next pending job using the worker token. Returns job:null immediately when no work is available, otherwise a job containing a new secret receipt. Visibility defaults to 60 seconds and accepts 30-900 seconds. Redelivery is possible: make worker side effects idempotent. J

  • ack_agent_queue_job

    Mark a claimed job completed using the worker token and its current receipt. Repeating acknowledgement with the same winning receipt succeeds. A different, stale or expired claim receipt is a conflict. Completion does not reclaim the lifetime job allowance.

  • release_agent_queue_job

    Return a claimed job to pending using the worker token and its current receipt. On the fifth claim it becomes failed. The receipt is invalidated. Stale receipts conflict.

  • renew_agent_queue_job

    Move the active claim deadline using the worker token and current receipt. Visibility accepts 30-900 seconds, defaults to 60 seconds and is capped by the original queue expiry. A stale or expired receipt is a conflict. Queue lifetime is never extended.

  • create_dns_name

    Point a public hostname at an address you already control, for 24 hours. Use it when something needs a name rather than an address: a webhook target someone has to type, a staging box whose address moves, a service two agents must reach by the same name. No API key, no account an

  • read_dns_name

    Look up what a temporary DNS name points at and how long it has left. No token is needed: everything it returns is already public in DNS. Use it to confirm a name exists and resolves the way you expect before handing it to someone else. It fails once the name has expired, and a n

  • update_dns_name

    Change the address a temporary DNS name points at. Needs the dns_token from create_dns_name. Use it when the machine behind the name moved and you would rather keep the name than hand out a new one. The expiry does not move: the name still disappears 24 hours after it was created

  • delete_dns_name

    Remove a temporary DNS name now, before its 24 hours are up. Needs the dns_token. Use it when the work is done and the name should stop answering rather than sit there until it expires. The removal reaches the primary name server at once and the secondary follows by replication,

  • encode_data

    Encode text as Base64, Base64url, Base32, Base58 or hex, as URL percent-encoding or as HTML entities, or decode such a string. Decoding answers decoded_text when the bytes are UTF-8 text and decoded_base64 when they are binary. Base58 uses the Bitcoin alphabet and takes at most 6

  • encode_audio

    Turn 1 to 128 bytes into a PCM16 WAV audio block using the AI SENSE audio-v1 modem. data is UTF-8 text unless input_encoding is base64. Audible tones are the default. ultrasound uses experimental 18.5 to 19.7 kHz tones, which some people can hear and some devices cannot carry. Pl

  • decode_audio

    Recover one checksum-verified AI SENSE audio-v1 message from a PCM16 WAV recording at 44100 or 48000 Hz, mono or stereo, at most 40 seconds. Give storage_id for a WAV file of at most 4 MiB, uploaded through REST Storage first. WAV recordings exceed the inline MCP request limit. R

  • hash_data

    Hash text with MD5, SHA-1, SHA-256, SHA-512, CRC32, Whirlpool, SHA3-256, SHA3-512, BLAKE2b-256 or BLAKE3 and answer the digest in hex, or for crc32 as an integer. Use sha256, sha3_256, blake2b or blake3 for integrity checks; md5 and sha1 are for systems that still expect them. ar

  • verify_hash

    Check that text matches a hash. Name the algorithm when you know it. Without it the algorithm follows from the hash: 8, 32, 40, 64 or 128 hex characters mean CRC32, MD5, SHA-1, SHA-256 or SHA-512, and an integer means CRC32 in decimal; whirlpool, sha3_256, sha3_512, blake2b and b

  • generate_random

    Generate a random number in a range (kind number, from and to, default 1 to 6), a color as #rrggbb (color), a GUID (guid), a password of 6 to 128 characters (password, length, default 12) or a passphrase of 2 to 12 word groups (passphrase, groups, default 4), which comes with its

  • time_formats

    The current time in several formats at once: a Unix timestamp, Unix time with microseconds, an ISO 8601 date and time at an optional UTC offset, and Swatch Internet Time. Named timezones such as Europe/Oslo are answered by get_current_time. No API key, no account and no sign up.

  • convert_timestamp

    Convert a Unix timestamp in seconds or milliseconds, or a date and time text, into a Unix timestamp, ISO 8601, RFC 2822 and UTC forms. offset sets the zone of the answer. The answer says what the input was read as. No API key, no account and no sign up.

  • list_timezones

    List the IANA timezones with their current UTC offsets, optionally only those at one offset such as +0530. No API key, no account and no sign up.

  • lookup_network

    Network facts: the public IP address this service sees for you (client_ip), your User-Agent (user_agent), the country, city, coordinates and timezone of an IPv4 address from a local GeoLite2 database (reverse_ip), or the first IPv4 address a domain resolves to (domain_ip). value

  • validate_email

    Check an email address: its syntax, whether its domain has MX records, listing up to five, and whether the domain has an address record. The mail server is not contacted, so a good answer does not prove that the mailbox exists. No API key, no account and no sign up.

  • validate_value

    Validate an IBAN, a payment card number (Luhn), a Norwegian organisation number (orgnr), a Norwegian bank account number (kontonummer) or a phone number, with the checksum and the normalized form where the type has them. Nothing is stored or looked up. No API key, no account and

  • slugify_text

    Turn text into a lowercase URL slug with words joined by hyphens. No API key, no account and no sign up.

  • jwt_token

    Create or check an HS256 JSON Web Token. encode signs payload with secret and answers jwt; decode verifies token with secret, including exp, nbf and iat, and answers decoded_payload. The secret is used for this call only and is not stored. No API key, no account and no sign up.

  • create_qr_code

    Make a QR code for a text or URL, as a PNG with error correction level H. The answer is the image. No API key, no account and no sign up.

  • read_qr_code

    Read the QR codes in a PNG, JPEG, GIF or WebP image. Several codes come back joined by newlines. Give image_base64 or storage_id. No API key, no account and no sign up.

  • html_to_pdf

    Render HTML to a PDF with JavaScript and network access turned off, so only the HTML sent is used and images must be inline data URLs. options can set page-size (A3, A4, A5, Letter, Legal, Tabloid), orientation (Portrait, Landscape) and margin-top, margin-bottom, margin-left, mar

  • crypto_wallet

    The balance of a public Bitcoin, Ethereum or Solana address, read from blockchain.info, a public Ethereum RPC node or the Solana mainnet RPC, or a newly generated key pair. A generated private key is sent once and not stored, but it has passed through this service, so use it for

  • json_csv_convert

    Convert between JSON rows and CSV. json_to_csv takes columns and rows, up to 5000 flat objects, and stores result.csv; csv_to_json takes data, the CSV text, and stores result.json. delimiter is a comma, a semicolon or a tab. spreadsheet_safe guards cells a spreadsheet would run a

  • html_markdown_convert

    Convert HTML to Markdown, or Markdown to HTML. html_to_markdown leaves out scripts, styles, forms and media and answers markdown and the page title, so a fetched page reads with fewer tokens. markdown_to_html answers html from CommonMark with GitHub tables, strikethrough and task

  • json_check

    Format or validate JSON text. format pretty-prints it (mode pretty, indent 2 or 4) or compacts it (mode compact); validate reports whether it parses and where it breaks. The result is stored for 24 hours and the answer has its storage_id and storage_url. No API key, no account an

  • match_tables

    Match the rows of two tables on one or more pairs of key columns, like a join, and store the matches as JSON for 24 hours. left and right are lists of row objects; keys lists pairs such as {"left":"id","right":"customer_id"}. No API key, no account and no sign up.

  • process_image

    Convert a JPEG, PNG, WebP, HEIC or supported static SVG to JPEG, PNG or WebP (format, quality, lossless). Vectorize a PNG or JPEG to black SVG paths on a transparent background (threshold). The trace fits within 1024 by 1024 pixels. For JPEG, PNG or WebP, compress (quality), resi

  • decide

    Omit model or use rules for the existing yes_no, choice and scale rule engine with probability, confidence and action. Use model clef, nimble or tev1 for noul, choice and score questions with instructions and criteria. tev1 is the smallest and fastest, tested by its maker in Engl

  • simulate_failure

    Get a chosen failure on purpose, to test how an agent or client handles it: an HTTP status from 200 to 504, an HTML error page (html), an empty body (empty) or JSON labelled as text (wrongtype), after an optional delay of up to 10 seconds. The result reports the status, content t

  • schedule_webhook

    Schedule an HTTP POST of a JSON payload to a public URL: once, after delay_seconds or at the Unix time fire_at, 5 seconds to 24 hours ahead, or repeatedly every 60 to 86400 seconds until 24 hours after creation. The URL must use a host name, not an IP address, and resolve to a pu

  • read_webhook_schedule

    Read a scheduled webhook: its status, attempts and, after it fired, the HTTP status and an excerpt of the answer. wait_seconds, up to 25, waits for the status to change before answering. No API key, no account and no sign up.

  • cancel_webhook_schedule

    Cancel a scheduled webhook that has not finished. A job that has already ended cannot be cancelled. No API key, no account and no sign up.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

  • ✓ Pass

    Maker matches the repo

    The registry name was verified against the domain aisenseapi.com (the registry checks domain ownership)

  • … Not checked yet

    Still maintained

    We have not read this repo from GitHub yet

  • … Not checked yet

    Has a licence

    We have not read this repo from GitHub yet

  • ✓ Pass

    Endpoint responds

    Responded in 886 ms (HTTP 200)

  • – Not applicable

    Sign-in with OAuth

    No sign-in needed

  • ✓ Pass

    No hidden instructions in tool descriptions

    Read 60 tool descriptions and found no hidden instructions to the AI

Compared with others in Design, images & audioi

  • More stars than 0% of the other 2187 servers in this category
  • Published to the registry more recently than 99% of the other 2187 servers in this category
  • Basic checks equal to or better than 100% of the other 2187 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is AI SENSE Free Public Tools safe?

It passed 3 of 3 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs in the maker’s cloud. Connect over the internet with nothing to install, but what you send passes through the maker’s servers.

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.18.0) reached the registry today.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

What can I use instead?

In the same category: Figma Context MCP, Claude Real Video, Figma MCP Server

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Give your coding agent access to your Figma data. Implement designs in any framework in one-shot.

Runs on your computer★ 16,165MITUpdated 5 months ago
Install

Claude Real Video

by HUANGCHIHHUNGLeo

Let any LLM watch a video locally — and search everything it has ever watched.

Runs on your computer★ 2,284MITUpdated 2 months ago
Install

Figma’s official server gives AI your design data so it can turn designs into code or describe them accurately. Connects to Figma’s cloud.

Runs in the cloud★ 2,152Updated 13 months ago
Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

Free Public REST APIs - AI SENSE AS

No API key | No sign-up | No cost

Provided by [AI SENSE AS](https://aisenseapi.com) (Oslo, Norway). Full endpoint reference: API.md | Repo: github.com/aisenseapi/aisense-free-public-rest-apis

Base URL: https://aisenseapi.com/services/v1/

Free public MCP endpoints

The AI SENSE MCP server is at:

https://aisenseapi.com/mcp

The AI SENSE MCP server covers Heartbeat, Lease, Agent Wake tasks, Agent Inbox, human approval, webhook capture, temporary storage, URL shortening, time and UUIDs. It needs no account or API key. Heartbeat uses create_heartbeat, read_heartbeat and ping_heartbeat. Lease uses create_lease_namespace, acquire_lease, renew_lease, release_lease and complete_lease. Agent Inbox uses create_agent_inbox and read_agent_inbox. See MCP.md for the tool list, data boundary and client examples.

The Agent Queue tools use separate read, write and worker tokens issued at creation. The semantic search tools use a read token and a write token in the same way.

Start with AGENT-GUIDE.md to choose tools, then AGENT-QUICKSTART.md for a complete Queue workflow and retry decisions. examples/comfyui runs image jobs through ComfyUI from several machines on Agent Queue, Storage and Webhook capture, with a fake renderer so the flow runs without ComfyUI.

The server reports version 1.18.0 and offers 79 tools: the workflow tools and the REST utility endpoints below as tools, apart from AIQ, ip_datetime and ping, which stay on REST. The official MCP Registry lists com.aisenseapi/free-public-tools version 1.17.0 as active and latest, published 5 November 2026 at 16:12 UTC.

aamio has its own MCP endpoint at https://aamio.at/mcp, eleven tools for ephemeral agent rendezvous: a thread with a secret read key and a public write address, a receipt of hashes that outlives it, presence, and the open board of needs and offers at https://board.aamio.at/. No account and no API key. The official MCP registry lists it as at.aamio/aamio. The AI SENSE endpoint does not proxy these tools either.

Verifyum has its own dedicated MCP endpoint at https://api.verifyum.com/mcp. It exposes the three Verifyum proof operations without an account or API key. File hashing still happens on the agent's machine. The browser flow, public HTTP API and published protocol remain available. The official MCP registry lists it as com.verifyum/mcp version 0.1.0. Finalized proofs also join hourly and daily Merkle checkpoints in the Verifyum Witness Layer. Nine records surround each finalized proof.

TierRecords
Primary evidenceOne finalized Solana Mainnet Memo transaction per proof
Independent corroborationHourly OpenTimestamps on Bitcoin, daily qualified EU timestamp, daily witness-cosigned Sigsum and daily Certificate Transparency certificate
Operator records and availability redundancyVerifyum Ed25519 signature, GitHub checkpoint log, Software Heritage and Internet Archive

The Solana transaction is the primary evidence. Deep Solana history generally requires an archival provider. Glasklar, Mullvad and Tillitis cosign the Sigsum digest with a quorum of two out of three. The qualified timestamp uses RFC 3161. Its eIDAS Article 41(2) presumption covers the daily checkpoint root alone. A Verifyum user proof is not a qualified electronic timestamp. Verifyum is not a qualified trust service. Software Heritage and Internet Archive show what was stored. They do not establish when the original file existed. The number of channels is not a quality score.

Every finalized proof is also announced on Telegram and in the Atom feed. These are announcement channels. They are excluded from the nine evidence records. Their timestamps date the announcement. They say nothing about the original file date.

An agent can also assemble one decision record locally from its instructions, prompt, model, parameters, tool calls and output, then anchor only the commitment. The proof shows that the exact record existed unchanged by the block time. It does not prove that the model actually ran with the recorded settings.


Free public Agent2Agent (A2A) endpoint

Agents that speak Agent2Agent can reach five of these capabilities at:

https://aisenseapi.com/a2a

JSON-RPC 2.0, protocol revision 1.0, no account and no API key. The agent card is a plain GET at https://aisenseapi.com/.well-known/agent-card.json.

A2A is the protocol for delegating work to another agent. MCP is the protocol for exposing tools. Most of this service is tools, so only the five task-shaped capabilities are offered over A2A: agent-wake, human-approval, agent-inbox, webhook-capture and agent-queue. The other tools are not reachable through it. MCP stays the richer workflow surface with its own tool schemas. Over A2A the queue skill creates a queue and returns its three role tokens; enqueueing, claiming and acknowledging stay on REST and MCP.

A2A puts no skill id on the wire, so the caller names the skill in a data part of the message, as {"skill": "agent-wake", "arguments": { ... }}. That is a convention this service documents, not a field the protocol defines, and a message without it is refused. The card declares streaming and pushNotifications false, so those methods answer -32004 and -32003. ListTasks returns an empty page, because nobody is authenticated and a task ID is the only credential there is. See API.md for the skills, task states, response shapes and error codes.


SpeedUp (.su) - token cost, measured properly

Every serialization format marketed for LLM input ships a token-saving claim measured against a single tokenizer. Agent traffic crosses vendors, so we measured instead of assumed: six formats and 33 single-construct probes, priced by five vocabulary families (OpenAI o200k, DeepSeek, Qwen, SentencePiece, Tekken), with each provider's own token counter as ground truth.

  • SU-PROFILE.md - the SpeedUp profile: eight writing conventions for agent-to-agent text, each citing its measured price tag
  • speedup/ - the measurement rig (Python, standard library only), corpus, probes and raw numbers; rerun everything with your own keys
  • The study - what survived measurement, what did not, and why we decided against shipping yet another format

Headline numbers: plain TSV averages 0.82x minified JSON across the five-vocabulary union and beats the token-oriented formats on every model; declaring columns once and sending values positionally is the entire mechanism (minus 34 percent per key-value pair); base64 costs 3.9-4.6x the plaintext it encodes; and single-letter key dictionaries lose to full keys on four of five vocabularies.


Why this exists

Most utility APIs require sign-up, rate limit tiers, or pricing for basic operations. This collection skips all of that. Drop a URL into curl, Python, JavaScript, or an LLM tool definition and it just works.

The collection covers two tiers of usefulness:

  • Workflow endpoints - the ones that solve real problems in pipelines and agent systems
  • Standard utilities - hashing, encoding, UUIDs, time, crypto - the building blocks

Three things to know before you write a client

These are service-wide and they decide how your error handling has to look.

The response key is named after the endpoint. /md5_hash returns md5_hash, /random_color returns random_color, /ping returns ping. There is no generic data or result wrapper. Do not guess the key - API.md lists every one.

Errors usually use `{"error": "message"}` with a non-2xx HTTP status. Check both the status and the error field. The legacy wallet-generation handlers can return an error object with HTTP 200. Workflow endpoints use non-2xx statuses, including 409 for conflicts and 410 for an expired record that has not yet been removed. Once removed, the same ID returns 404. Unknown routes also return 404. Consult each endpoint for its additional errors.

There is a rate limit: 5000 requests per IP per day. Exceeding it returns HTTP 429 in the same flat error shape as everything else. The count resets at 22:00 UTC from late March to late October and at 23:00 UTC the rest of the year (midnight in Norway, time zone Europe/Oslo), and the 429 carries Retry-After with the seconds until then.


The high-value endpoints

Heartbeat - know when a worker stops checking in

Create a monitor with an expected check-in interval, a grace period and one action for a missed deadline. The action can POST to a public webhook or wake an existing Agent Wake webhook task.

curl -X POST https://aisenseapi.com/services/v1/heartbeat \

-H "Content-Type: application/json" \ -d '{ "expect_every_seconds": 300, "grace_seconds": 60, "on_miss": { "url": "https://example.com/agent-offline", "payload": { "agent": "worker-7" } } }'

The response gives you an unguessable heartbeat_id, ping_url and status_url. Call the ping URL with POST after each successful cycle. Each ping moves the expected deadline. It does not move the fixed 24-hour expiry. A missed deadline fires once, with no retry.

MCP clients can use create_heartbeat, read_heartbeat and ping_heartbeat for the same state.

Webhook destinations are checked for SSRF at creation and delivery. Private and reserved addresses, URL credentials, fragments and redirects are blocked. See API.md for the states and response fields.


Lease - one winner for shared agent work

Lease coordinates workers without an account. Mint a private namespace, then claim a key for a short period:

curl -X POST https://aisenseapi.com/services/v1/lease/namespace \

-H "Content-Type: application/json" -d '{}'

curl -X POST https://aisenseapi.com/services/v1/lease \ -H "Content-Type: application/json" \ -d '{ "namespace": "ns_...", "key": "invoice:2026-09-05", "ttl_seconds": 60, "fingerprint": "charge-order-501" }'

The winner receives an owner_token and a monotonic fencing_token. A second worker receives HTTP 409 while the lease is held. The owner can renew, release or complete the lease with a JSON result. Later callers with the same key and fingerprint can reuse that completed result.

The lease has a fixed absolute expiry 24 hours after its first acquisition. Renewals cannot extend it. Raw keys, namespaces, owner tokens and fingerprints are not stored. See API.md for the full acquire and completion flow.

The matching MCP tools are create_lease_namespace, acquire_lease, renew_lease, release_lease and complete_lease.


Agent Queue - share temporary work

Agent Queue gives producers and workers a shared queue for small JSON jobs.

curl -X POST https://aisenseapi.com/services/v1/queue \

-H "Content-Type: application/json" -d '{}'

curl -X POST https://aisenseapi.com/services/v1/queue/QUEUE_ID/jobs \ -H "Authorization: Bearer WRITE_TOKEN" \ -H "Content-Type: application/json" \ -d '{"job_key":"report:42","payload":{"report_id":42}}'

curl -X POST https://aisenseapi.com/services/v1/queue/QUEUE_ID/claim \ -H "Authorization: Bearer WORKER_TOKEN" \ -H "Content-Type: application/json" -d '{"visibility_timeout":60}'

Replace the uppercase placeholders with creation response values. Keep the three tokens: they are issued only once. A claim returns one job with a secret receipt, or job: null when empty. The worker performs the work, then posts {"receipt":"RECEIPT"} to /queue/QUEUE_ID/jobs/JOB_ID/ack using its work

Only the beginning is shown; read the rest in the repo

Ask PopNx