TL;DR
- HeyReach is the strongest choice here for an agency building campaign creation, shared inbox retrieval and approved replies into its own workflow. Its API includes direct conversation messaging and a webhook for every reply.
- La Growth Machine is the strongest fit for a multichannel application that needs LinkedIn and email messages, conversations and sent/received inbox events. API access starts on Pro, at €120 per identity monthly.
- Dripify fits lead enrolment, campaign reporting and CRM status updates. Its current API now includes activity logs, tags and custom fields, but no direct LinkedIn message-sending endpoint is listed.
- Expandi fits an existing campaign that needs external lead input and event-driven handoffs. Its reversed webhooks are narrower than a general inbox API, and reply detection can take a few hours during active hours.
- Buy around the operation you need: enrol a lead, detect a reply, read the thread or send an approved answer. Those are four different capabilities. An API request limit is also separate from LinkedIn campaign sending limits.
What an outreach integration actually needs
A tool can advertise an API while supporting only statistics and lead imports. That is useful for a CRM sync, but insufficient for a custom reply assistant. Conversely, an inbox API can read and send messages without being the right place to create campaigns from scratch.
Separate the job into four operations. Enrolment takes an approved prospect and adds them to the right sender and campaign. Events tell your application that a connection, reply or completed sequence occurred. Conversation retrieval supplies the thread needed to understand the reply. Message sending returns an approved response to that specific conversation. The final operation should not be inferred from a webhook labelled “reply”.
This guide compares those operations, qualifying plans, authentication and documented throughput for four established outreach products. It covers an operator connecting two LinkedIn senders to a CRM and a reply queue, rather than ranking their general sequence editors. Capabilities and pricing bases were assessed from official sources checked on 30 September 2026; no live account integration is claimed.
API scope and two-sender costs compared
| Tool | Practical integration scope | Reply event and thread boundary | Authentication and documented API limit | Two senders, monthly base |
|---|---|---|---|---|
| HeyReach | Campaign creation/control, leads, conversations and direct conversation messages | First-reply and every-reply events are separate; thread retrieval available | X-API-KEY; 300 requests/minute |
$158 at the $79 per-sender entry rate |
| La Growth Machine | Campaigns, leads, LinkedIn/email messaging, conversations and inbox webhooks | Inbox webhook covers each sent or received message | Bearer token or x-api-key; 50 calls/10 seconds/key |
€240 on Pro |
| Dripify | Campaign/lead data, uploads, activity logs, tags and custom fields | New reply webhook transfers conversation messages; legacy first-reply trigger deprecated; no listed direct message-sending endpoint | X-Api-Key; 60/minute and 5,000/day/key |
$158 on Pro; $198 if both need Advanced |
| Expandi | Add leads to existing campaigns, pause/resume leads, campaign event handoffs | Reply events depend on periodic account sync; reversed webhooks are campaign inputs | Secret-bearing webhook URLs; no numerical API quota stated in the cited guide | $198 on Business |
These are subscription bases, before tax, middleware, enrichment and implementation. HeyReach's volume rate for ten senders is not the entry rate for two. Dripify Advanced adds team controls; it is not required merely to unlock the Pro API. LGM's euros are kept separate from the dollar plans. Expandi and Dripify annual discounts do not reduce a month-to-month invoice. HeyReach pricing, LGM pricing, Dripify pricing, Expandi pricing.
HeyReach for campaign and inbox applications
HeyReach offers the most complete LinkedIn-specific application interface in this shortlist. Its campaign API can create a configured draft, assign accounts, define the sequence and start the campaign separately. That separation is useful when a client manager reviews a campaign before activation. Settings and sequence changes also have campaign-state rules: an active campaign is not freely editable through every endpoint. Updating account assignments replaces the supplied account set, rather than simply appending another sender. Campaign API guide.
The inbox interface supplies the other half of the workflow. GetConversationsV3 uses cursor pagination with up to 100 conversations per page; GetChatroom retrieves a conversation with its messages; SendMessage sends to a LinkedIn conversation using the relevant sender. V3 omits email and custom fields from the correspondent profile, so an application needing that data should retrieve the lead separately. This is a usable custom inbox foundation, rather than a report export presented as conversation access. Official API reference.
Webhook selection matters. MESSAGE_REPLY_RECEIVED covers the first reply, while EVERY_MESSAGE_REPLY_RECEIVED includes subsequent replies and InMail replies. Other events include connection acceptance, sent messages, campaign completion and lead tag updates. Campaign filters let an operator route one client's events to a separate workflow. The API uses an organization API key in X-API-KEY, with a shared 300-request-per-minute limit and a 429 response when exceeded. Those are integration requests, not permission to send 300 LinkedIn messages a minute. Official API reference.
Best fit: an agency or operator building a CRM-connected inbox, reply routing or programmatic campaign setup across senders. Less suitable: a buyer whose central requirement is a single LinkedIn-and-email message API; LGM covers that multichannel job more directly.
Verdict: choose HeyReach for a LinkedIn-specific application that needs both campaign control and conversation operations. At two entry-rate senders, its $158 monthly base is competitive with Dripify Pro while supplying a different set of operations.
La Growth Machine for multichannel message workflows
LGM's API covers campaigns, audiences, lead search and updates, conversations, identities and messages. Its published scope includes LinkedIn text and voice messages as well as email. An inbox webhook can deliver every sent or received message with lead and conversation context to your application. That suits a shared task queue where a salesperson needs the whole exchange across channels, not just a one-time campaign conversion event. LGM API guide.
API access starts on Pro. The monthly base is €120 per identity, or €100 monthly equivalent with annual billing: two identities cost €240 monthly or €2,400 annually. An identity represents a sending profile, so collaborator access is not interchangeable with another sender. Buying Basic for two people does not supply the documented Pro API entitlement. LGM pricing.
Requests go to its apiv2 service using a bearer token or x-api-key. The guide states 50 calls per ten seconds per key; a 429 requires waiting before retrying. Keys grant full account access. That makes LGM a strong operational interface, but a poor fit if the integration must be restricted to a read-only API credential. Its API enrichment also has a separate consumption basis: email enrichment costs five credits, LinkedIn-profile enrichment one, and the combined operation five. Subscription seats do not make every enrichment request free. LGM API guide.
Best fit: a sales operations team building a multichannel message workflow, with conversations and events driving CRM tasks. Less suitable: an inexpensive LinkedIn-only enrolment feed, or an application requiring narrowly scoped read-only credentials.
Verdict: pay for Pro when the application actually uses its multichannel and conversation operations. The additional scope justifies the product choice more clearly than a generic claim that it has more integrations.
Dripify for enrolment and campaign data
Dripify's API is now broader than its older help summary suggests. The current reference lists campaign statistics, lead lists, campaign uploads, append-to-list operations, individual leads, activity logs, tags and custom-field updates. A CRM workflow can match a prospect by profile URL or email, attach an internal qualification field, tag the lead and read campaign progress. Team and member statistics are also available, with access restrictions on team-member data. Current API reference.
That does not make it a custom messaging API. No direct LinkedIn send-message endpoint is listed in the reference. An activity log is useful for timeline reconciliation, but should not be treated as a complete inbox thread export. Its newer campaign documentation adds conversation transfer through a reply webhook, a different interface from a direct message-history endpoint. For direct replies, the absence of a listed send endpoint remains decisive. Current campaign webhook documentation.
API access is on Pro and Advanced. Pro is $79 monthly per user, or $59 monthly equivalent annually; Advanced is $99 or $79 respectively. Two Pro senders therefore cost $158 monthly or $1,416 annually. An owner needing Advanced team controls with one Pro sender would instead pay $178 monthly. The API uses X-Api-Key, permits 60 requests per minute and 5,000 daily per key, and returns rate-limit headers plus Retry-After on a 429. Pagination defaults to 25 records and permits up to 100 per page. Dripify pricing, API reference.
Select the current After LinkedIn reply is received trigger. Dripify's July 2026 campaign guide says it transfers new conversation messages, including the user's messages and the lead's replies, as available in the Dripify inbox. The older After lead's first LinkedIn reply trigger remains deprecated; its paused-lead limitation should not be applied to the new trigger. This improves continuing CRM conversation capture, while the inbox-availability boundary remains. Current reply webhook.
Best fit: send approved leads into campaigns, update fields and transfer available conversation messages to the CRM while people handle replies inside Dripify. Less suitable: an application that needs a documented direct send-reply endpoint.
Verdict: choose Pro for the campaign-data job. Choose Advanced for team-management needs, rather than assuming it adds a currently undocumented reply API.
Expandi for campaign handoffs
Expandi's reversed webhooks provide a practical input to an existing campaign. Create the campaign in the UI, obtain its webhook URL and POST a LinkedIn profile URL with the supported fields or placeholders. Separate URLs can pause or resume a campaign lead using the contact identifier. This is useful for taking a qualified CRM record and placing it into a defined outreach sequence; it is narrower than arbitrary campaign creation and conversation messaging. Reversed webhooks guide.
Outgoing events include contact replied, connection accepted, message sent, contact added and campaign finished, with more specific variants such as a reply to a campaign message or acceptance by a contact in an active campaign. Use the event matching your business question: a general connection acceptance can include activity outside the target campaign. Reply-generated follow-up content can be passed through a campaign placeholder, but that is a campaign workflow, not evidence of a general direct-chat endpoint. Event catalogue.
Expandi's help is clear about timing. Reply detection occurs through account synchronization every few hours during active hours. If a user manually replies before that sync, the latest message can be outbound and the received-reply webhook may not fire. Webhook time-delta settings can further batch delivery at one, four, eight, twelve or 24 hours. This makes Expandi workable for asynchronous CRM handoffs, but unsuitable as the only trigger for an immediate-response promise. Webhook timing guide.
Business costs $99 per sender monthly, or $79 monthly equivalent annually: two senders are $198 monthly or $1,896 annually. Treat reversed-webhook URLs as credentials because their secret is part of the URL. The cited integration guide does not publish a numerical request quota, so a supposed “unlimited API” allowance should not enter the cost comparison. Its documented batching and event history are more useful buying facts. Expandi pricing, Reversed webhooks guide.
Best fit: an existing Expandi campaign receiving qualified leads and sending periodic CRM events. Less suitable: a custom inbox requiring guaranteed capture of every message and fast direct responses.
Verdict: use Expandi when its campaign model already fits the operation. For an application built around fresh conversations, prefer HeyReach or LGM.
A two-sender reply-routing workflow
Assume two sales senders enrol 400 approved prospects per month and generate 80 conversations requiring review. These are planning assumptions, not predicted vendor results. The workflow stores the normalized LinkedIn profile, campaign ID, sender ID and CRM owner, then records each received event before assigning a task.
With HeyReach, subscribe to the every-reply event, retrieve the chatroom and send the salesperson's approved answer to the same conversation. With LGM, use the received inbox event and its conversation context, keeping sent-message events as part of the timeline. With Dripify, route the first response to a human inbox task and use the API for lead fields and reporting. With Expandi, let the synchronized reply event create an asynchronous CRM task; avoid promising an immediate assistant response from that feed.
For a custom inbox, suppose each of the 80 conversations requires three calls: retrieve the thread, look up or update the lead, and send an approved message. That is 240 API calls monthly, plus enrolment, pagination and reconciliation. HeyReach's 300/minute and LGM's 50/ten seconds readily accommodate that assumed volume when calls are paced. The Dripify limit also accommodates an equivalent data-sync volume, but the missing send operation means throughput alone cannot make the workflows equivalent.
Economics depend more on review time than this low request count. At $50 per hour, saving four minutes per conversation saves 320 minutes, or $266.67 monthly. Against an existing two-sender Dripify Pro setup, HeyReach has the same $158 subscription base; the business case is implementation and time saved, not a subscription discount. Moving the other way to Expandi adds $40 monthly at these bases, which needs 48 minutes of additional monthly value to break even. LGM should be evaluated in euros using the team's own currency and labour assumptions; no artificial exchange-rate comparison is needed.
A webhook handler should acknowledge the event promptly, store it and process it in a queue. Deduplicate deliveries using stable event or message identifiers where provided; otherwise use sender, conversation, event type and timestamp together. Honour 429 backoff, keep the sender-to-CRM mapping and reconcile missed events against available inbox or campaign data. These few controls prevent duplicate tasks and wrong-sender replies without turning a practical integration into a large procurement project.
Use our LinkedIn GTM playbook to connect the campaign, reply queue and CRM ownership rules. Middleware subscriptions and setup labour remain additional costs; the $266.67 saving is a threshold for that work, not an all-in ROI guarantee.
Which integration to choose
Choose HeyReach for a LinkedIn-specific custom application that needs campaigns, inbox context and direct approved replies. Choose LGM Pro when LinkedIn and email conversations belong in one application. These two are the most natural shortlist for a reply assistant.
Choose Dripify Pro for enrolment, tagging, qualification fields and campaign reporting with a human-managed inbox. Choose Expandi for external inputs and periodic handoffs around campaigns you already operate. Their narrower interfaces can still be good purchases when they match the actual job.
The decisive question is the last required operation. If the system only needs to assign a task after a reply, campaign events may be enough. If it must read the complete conversation and return an approved answer, buy documented conversation and messaging operations rather than an API badge.
FAQ
Does an API let me bypass LinkedIn sending limits?
No. The request quota controls access to the vendor interface. LinkedIn account activity and campaign schedules remain separate constraints. A statistics request and a LinkedIn message are not interchangeable units.
Which tool supports every reply rather than only the first?
HeyReach documents a separate EVERY_MESSAGE_REPLY_RECEIVED event. LGM documents inbox webhooks for each sent or received message. Dripify's current After LinkedIn reply is received trigger transfers new messages available in its inbox; its deprecated first-reply trigger has different limits. Expandi's detection depends on account synchronization.
Can Dripify send LinkedIn replies through its current API?
No direct send-message endpoint is listed in the current reference used here. Its useful current scope includes campaign uploads, activity logs, tags and custom fields. Keep direct reply handling in its inbox for this buying decision.
Is Expandi's reversed webhook a full public inbox API?
It supplies external inputs to existing campaigns and lead pause/resume controls. That is enough for many CRM handoffs, but it does not establish arbitrary conversation retrieval and direct messaging.
What is the cheapest qualifying two-sender setup here?
HeyReach at its entry sender rate and Dripify Pro both have a $158 monthly subscription base. Their API scope differs. LGM Pro is €240 and Expandi Business $198; tax, enrichment, middleware and implementation are separate.
