hive-mcp-flag

Feature flag service for the A2A network — Hive Civilization. DID-keyed targeting, percentage rollouts, x402 USDC settlement on Base L2. MCP 2024-11-05. Inbound only.

Disable a runaway behavior, gate a new tool behind a DID-prefix canary, or ramp a config change to 25% of agents — without redeploying the agent. LaunchDarkly-shaped semantics, agent-native primitives.

brand : Hive Civilization gold #C08D23 (Pantone 1245 C)
spec  : MCP 2024-11-05 / Streamable-HTTP / JSON-RPC 2.0
wallet: W1 MONROE 0x15184bf50b3d3f52b60434f8942b7d52f2eb436e (Base)

Quick start

git clone https://github.com/srotzin/hive-mcp-flag
cd hive-mcp-flag
npm install
npm start
# hive-mcp-flag on :3000

Hosted endpoint: https://hive-mcp-flag.onrender.com/mcp

Tools and pricing

Tool	USD / call	Notes
`flag_eval`	$0.0005	Evaluate a flag for a DID; returns resolved value and matched rule.
`flag_list`	free	List flags owned by a DID.
`flag_describe`	free	Full flag definition and recent evaluations.
`flag_create`	$0.001	Create a flag with default value and targeting rules.
`flag_update`	$0.0005	Update default value or targeting rules. Owner-only.
`flag_delete`	$0.001	Tombstone a flag. Owner-only.

All payments are inbound. Submit a Base USDC tx_hash (caller → W1) in the request body or x402-tx-hash header. The shim reads the receipt from Base RPC, decodes the USDC Transfer log, and verifies recipient and amount before serving the call.

Targeting rules

Rules evaluate in declared order. First match wins. If none match, the flag's default_value is returned.

[
  { "type": "did_match",  "dids": ["did:hive:0xabc"], "value": true },
  { "type": "did_prefix", "prefix": "did:hive:",      "value": true },
  { "type": "rollout",    "percent": 25,              "value": true }
]

rollout uses SHA256(did + flag_key) mod 100, so the same (did, flag_key) pair always falls in the same bucket — sticky variant assignment with no extra storage.

REST API

POST   /v1/flag/eval                # body: { flag_key, evaluating_did, tx_hash }
GET    /v1/flag/list?owner_did=...
GET    /v1/flag/{name}              # describe
POST   /v1/flag                     # create
PATCH  /v1/flag/{name}              # update — owner-only
DELETE /v1/flag/{name}              # tombstone — owner-only
GET    /v1/flag/today               # revenue snapshot
GET    /health                      # service health
GET    /.well-known/mcp.json        # MCP discovery
POST   /mcp                         # JSON-RPC 2.0

MCP example

{
  "jsonrpc": "2.0", "id": 1, "method": "tools/call",
  "params": {
    "name": "flag_eval",
    "arguments": {
      "flag_key": "new_routing_v2",
      "evaluating_did": "did:hive:0xabc",
      "tx_hash": "0xBASE_TX_PAYING_$0.0005_USDC_TO_W1"
    }
  }
}

Real rails

Surface	Library	Behavior
Persistence	`better-sqlite3`	SQLite at `/tmp/flag.db`, WAL mode, transactional create/update.
Signature verification	`ethers.verifyMessage`	Recovers the signer of a message and compares against a claimed address.
Payment verification	`ethers.JsonRpcProvider`	Reads tx receipt from Base RPC, decodes USDC `Transfer` logs, asserts `to == W1` and `amount >= asking_usd`.

Set VERIFY_ONCHAIN=false only for local development or testing — the default and the production deployment verify on-chain.

Environment

Var	Default	Purpose
`PORT`	`3000`	HTTP port
`ENABLE`	`true`	Master switch (`false` to brown-out)
`WALLET_ADDRESS`	W1	Base L2 receiver
`BASE_RPC_URL`	`https://mainnet.base.org`	RPC for receipt reads
`VERIFY_ONCHAIN`	`true`	Read receipts on Base before serving paid calls
`MAX_FLAGS_PER_DID`	`500`	Per-owner cap
`DB_PATH`	`/tmp/flag.db`	SQLite file

Caps

MAX_FLAGS_PER_DID = 500
Max targeting rules per flag: 50
Request body limit: 256 KB

Out of scope (v1.1+)

Flag prerequisites (B depends on A), auto-ramping rollouts, push notifications and change webhooks, multi-environment namespaces, dashboard UI.

Permanently rejected: instruments, predictions, or derivatives based on flag states.

Hive Civilization · MIT · github.com/srotzin/hive-mcp-flag

Hive Flag