diff --git a/src/chain.js b/src/chain.js
new file mode 100644
index 0000000..6ce54c9
--- /dev/null
+++ b/src/chain.js
@@ -0,0 +1,78 @@
+const http = require('http')
+const https = require('https')
+const { URL } = require('url')
+const config = require(`./config/${process.env.NODE_ENV || 'dev'}`)
+
+// Minimal POST to the EOS node (same transport style as GetActionsReader).
+function post (path, body) {
+  return new Promise((resolve, reject) => {
+    const url = new URL(path, config.blockchain.url)
+    const data = JSON.stringify(body)
+    const transport = url.protocol === 'https:' ? https : http
+    const req = transport.request({
+      hostname: url.hostname,
+      port: url.port || (url.protocol === 'https:' ? 443 : 80),
+      path: url.pathname,
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json', 'Content-Length': Buffer.byteLength(data) }
+    }, res => {
+      const chunks = []
+      res.on('data', chunk => chunks.push(chunk))
+      res.on('end', () => {
+        try { resolve(JSON.parse(Buffer.concat(chunks).toString())) } catch (e) { reject(e) }
+      })
+    })
+    req.setTimeout(30000, () => req.destroy(new Error('request timeout')))
+    req.on('error', reject)
+    req.write(data)
+    req.end()
+  })
+}
+
+// Fetch every on-chain claim for a single action via the `byaction` secondary
+// index (index_position 2). An action realistically has far fewer than the limit;
+// if the node still reports more, throw so we never compute an ordinal off a
+// truncated set (fail-safe — the block retries).
+async function claimsForAction (communityContract, actionId) {
+  const res = await post('/v1/chain/get_table_rows', {
+    json: true,
+    code: communityContract,
+    scope: communityContract,
+    table: 'claim',
+    index_position: 2,
+    key_type: 'i64',
+    lower_bound: actionId,
+    upper_bound: actionId,
+    limit: 5000
+  })
+  if (!res || !Array.isArray(res.rows)) throw new Error(`get_table_rows(claim) returned no rows for action ${actionId}`)
+  if (res.more) throw new Error(`too many claims for action ${actionId} to page safely`)
+  return res.rows
+}
+
+// Resolve the real on-chain claim id for the claim being processed.
+//
+// The chain assigns claim ids sequentially (get_available_id) and NEVER deletes a
+// claim (verifyclaim only mutates status), and the `claimaction` payload does not
+// carry the generated id. So for a given (action, claimer), the nth claim by
+// ascending id is the nth `claimaction` event-source processes for that pair — in
+// live AND replay. `ordinal` is the count of claims already recorded in the DB for
+// this pair (0-based index of the new one). Throws if the chain doesn't have that
+// many claims yet, so a transient/ordering problem retries the block instead of
+// writing a wrong id.
+async function resolveClaimId (communityContract, actionId, maker, ordinal) {
+  const mine = (await claimsForAction(communityContract, actionId))
+    .filter(c => c.claimer === maker)
+    .sort((a, b) => Number(a.id) - Number(b.id))
+
+  const claim = mine[ordinal]
+  if (!claim) {
+    throw new Error(
+      `resolveClaimId: chain has ${mine.length} claims for action ${actionId} / ${maker}, ` +
+      `need index ${ordinal}. Retrying block.`
+    )
+  }
+  return Number(claim.id)
+}
+
+module.exports = { resolveClaimId }
diff --git a/src/updaters/community.js b/src/updaters/community.js
index d17a368..489bf52 100644
--- a/src/updaters/community.js
+++ b/src/updaters/community.js
@@ -3,6 +3,8 @@ const {
   getSymbolFromAsset,
   parseToken
 } = require('../eos_helper')
+const config = require(`../config/${process.env.NODE_ENV || 'dev'}`)
+const { resolveClaimId } = require('../chain')
 
 async function createCommunity (db, payload, blockInfo) {
   console.log(`Cambiatus >>> Create Community`, blockInfo.blockNumber)
@@ -434,7 +436,37 @@ async function claimAction (db, payload, blockInfo, context) {
   })
   if (Number(existing) > 0) return
 
+  // The DB claim.id MUST equal the chain claim id — the frontend signs
+  // verifyclaim(claim.id) against the chain. The `claimaction` payload does not
+  // carry the id (the contract generates it), so historically we let the DB serial
+  // assign it, which drifts from the chain id after any duplicate/extra insert and
+  // leaves claims unverifiable. Recover the real id from chain: the nth claim (by
+  // ascending id) for this (action, claimer) is the nth we process for that pair.
+  //
+  // On any failure (chain unreachable, unexpected count) we fall back to the serial
+  // rather than throw — a throw here becomes an unhandledRejection → process exit →
+  // pm2 crash-loop. The serial is realigned to the chain by the one-time
+  // claims-id-reconciliation, so the fallback stays correct unless a new drift is
+  // introduced; the explicit-id path is what makes it robust against that.
+  let claimId
+  try {
+    const ordinal = Number(await db.claims.count({
+      action_id: payload.data.action_id,
+      claimer_id: payload.data.maker
+    }))
+    claimId = await resolveClaimId(
+      config.blockchain.contract.community,
+      payload.data.action_id,
+      payload.data.maker,
+      ordinal
+    )
+  } catch (e) {
+    logError('Could not resolve chain claim id, falling back to serial', e)
+    claimId = undefined
+  }
+
   const data = {
+    ...(claimId ? { id: claimId } : {}),
     action_id: payload.data.action_id,
     claimer_id: payload.data.maker,
     status: 'pending',