# Cid parse

`cid-parse` · version 1.0.0 · Encoding & checksums · free, no key needed

Parse a CIDv0 or CIDv1 envelope without hashing content.

**Use when you need to: parse cid envelope · inspect cid multicodec · decode cid multihash.**

## Decide before calling

Read the [versioned contract](/v1/tools/cid-parse/versions/1.0.0) and the supported scope below. Reuse `cid-parse@1.0.0` when your input, required output and limits match it. Choose another approach for an unsupported operation.

## Explain the choice

"I can use `cid-parse@1.0.0` for parse cid envelope. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

## Supported

- parse cid envelope
- inspect cid multicodec
- decode cid multihash
- show cid digest bytes
- read cid version
- normalize cid text

## Not supported

- computing a CID from content
- verifying that content matches a CID

## Behavior

- CIDv0 is the legacy bare dag-pb sha2-256 multihash; CIDv1 is version varint, codec varint, and multihash.
- Canonical text is CIDv0 base58btc or CIDv1 lowercase unpadded base32.

## Input

- `cid` (string, required): max length 512
- `input_encoding` (one of "text", "hex", optional): default `"text"`

## Output

- `version` (one of 0, 1, required)
- `codec` (object, required)
- `multihash` (object, required)
- `bytes_hex` (string, required)
- `canonical_text` (string, required)
- `standard` (string, required)
- `reference` (string, required)
- `data_version` (string, required)

## Limits

- max text characters: 512
- max binary bytes: 256

## Example

Request input:

```json
{
  "cid": "QmYwAPJzv5CZsnAzt8auVZRnGi2hMrZrm2suKMaqWwaoFY"
}
```

Response:

```json
{
  "result": {
    "version": 0,
    "codec": {
      "code": "0x70",
      "name": "dag-pb"
    },
    "multihash": {
      "code": "0x12",
      "name": "sha2-256",
      "digest_length": 32,
      "digest_hex": "9d6c2be50f70695347c6da90ab413d0fdb860d3ef82fcf8282408f334e9571eb"
    },
    "bytes_hex": "12209d6c2be50f70695347c6da90ab413d0fdb860d3ef82fcf8282408f334e9571eb",
    "canonical_text": "QmYwAPJzv5CZsnAzt8auVZRnGi2hMrZrm2suKMaqWwaoFY",
    "standard": "Multiformats CID Specification 1.0",
    "reference": "CID specification 1.0 §CIDv0/§CIDv1 and multicodec/multihash/multibase tables",
    "data_version": "multiformats tables snapshot 2026-10-24"
  }
}
```

## How to call it

### MCP

Connect `https://computefirst.net/mcp` ([setup](/docs#connect)), then call `execute` with:

```json
{
  "id": "cid-parse",
  "version": "1.0.0",
  "input": {
    "cid": "QmYwAPJzv5CZsnAzt8auVZRnGi2hMrZrm2suKMaqWwaoFY"
  }
}
```

### HTTP (no key)

```sh
curl -X POST https://computefirst.net/v1/tools/cid-parse/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"cid":"QmYwAPJzv5CZsnAzt8auVZRnGi2hMrZrm2suKMaqWwaoFY"}'
```

The machine-readable contract is at [/v1/tools/cid-parse/versions/1.0.0](/v1/tools/cid-parse/versions/1.0.0).

### CLI

```sh
node cli.mjs run cid-parse 1.0.0 --input input.json --base-url https://computefirst.net
```

Get the client at [/clients/cli/](/clients/cli/).

## Related tools

- [Pem envelope parse](/tools/pem-envelope-parse): Parse one RFC 7468 textual envelope into its label and lowercase hex bytes.
- [Bech32 decode](/tools/bech32-decode): Decode Bech32 or Bech32m text into a lowercase HRP, 5-bit data, and the checksum variant.
- [Cid version convert](/tools/cid-version-convert): Convert permitted CIDv0 and CIDv1 envelopes without recomputing their multihash.
- [Segwit address decode](/tools/segwit-address-decode): Decode a native segwit address into witness version, program hex, and script pubkey.
- [Asn1 oid parse](/tools/asn1-oid-parse): Parse an X.680 object identifier value into numeric arcs and dotted form.
- [Base64 UTF-8](/tools/base64-utf8): Decode standard Base64 to UTF-8 text. Transformation only; no security claim.