Missive to Podium Migration: The Technical Guide

What Is a Missive to Podium Migration?

A Missive to Podium migration is the process of extracting contacts, conversations, message history, labels, assignments, and metadata from Missive's collaborative inbox and loading them into Podium as Contacts, Conversations, and Messages tied to specific Locations.

This is a data-model transformation, not a platform swap. Missive treats communication as a shared asset. An email arrives, team members chat internally within the context of that email, assign it, and reply. The channel — Email, SMS, WhatsApp — is secondary to the collaboration layer. Podium treats communication as a direct line between a physical business location and a consumer. It is heavily optimized for short-form SMS, review requests, and payment links. Every interaction is strictly tied to a location_id.

The architectures diverge at the foundation. Missive operates on an organization-based, channel-agnostic model where conversations belong to shared mailboxes and teams. Podium operates on a location-based, SMS-centric model where every conversation is tied to a physical business location and a contact's phone number is the primary identifier.

This mismatch creates immediate technical friction. Injecting a 40-message, HTML-heavy Missive email thread into Podium's SMS-first UI creates an unreadable experience. Internal Missive comments cannot natively exist alongside external messages in Podium. A successful migration requires aggressive data transformation, not just data transfer.

A native migration path does not exist. Podium has no import wizard for Missive data. Missive has no export-to-Podium option. The only reliable path is a custom ETL pipeline using both platforms' REST APIs.

For related migration guides, see:

• Missive to Pylon Migration: Covers Missive extraction patterns and Pylon's import model.
• Tidio to Podium Migration: For teams moving chat-first data into Podium.
• Podium to Crisp Migration: For teams moving from Podium to a chat-first platform.
• Podium to Unthread Migration: For teams shifting from Podium to a Slack-native helpdesk.
• Missive Migration Checklist: Pre-migration audit for any Missive source migration.

Why Teams Move from Missive to Podium

The switch is driven by business-model fit, not feature dissatisfaction.

• SMS-first customer engagement. Missive supports SMS, but it's not the primary channel. Podium is purpose-built for SMS-driven customer conversations — lead capture, appointment booking, review requests, and text-to-pay all live natively in the platform.
• Review management. Podium includes built-in Google and Facebook review solicitation and management. Missive has no review management capability.
• Payments. Podium offers text-to-pay invoicing. Missive doesn't handle payments.
• Local business focus. Podium's location-based architecture and webchat-to-text capture are designed for multi-location local businesses (auto dealers, dental offices, home services). Missive is designed for knowledge-worker teams managing email-heavy workflows.
• AI lead response. Podium's AI Employee can auto-respond to inbound leads within minutes across web, SMS, and Google channels. Missive's AI features focus on drafting assistance and email triage, not autonomous lead engagement.

Platform Architecture Comparison

Data Mapping: Missive → Podium

This is where most migrations stall. The entity relationships are different enough that a 1:1 copy is impossible.

Contacts

Missive Contacts → Podium Contacts. This is the most straightforward mapping. Missive stores contacts in Contact Books with flexible fields. Podium contacts require a locationUid and use phone number or email as the primary identifier.

Missive contacts are highly flexible — they can exist with only an email address, only a social handle, or just a name. Podium contacts are designed around SMS. During extraction from Missive (GET /v1/contacts), you must sanitize phone numbers into E.164 format. Contacts without phone numbers or emails should be flagged in an exception report.

Podium Contact Upsert Behavior

This is a critical implementation detail that determines whether you create duplicates or cleanly update existing records.

When you POST /v4/contacts, Podium checks whether a contact with the same phone number (E.164) already exists at that locationUid:

• Phone match found at the same location: Podium returns a 409 Conflict response with the existing contact's uid in the response body. Your pipeline must catch this, extract the existing uid, and proceed with that contact ID for all subsequent message imports. Do not retry the creation — treat 409 as a successful lookup.
• Phone match at a different location: Podium treats this as a new contact at the new location. A cross-location duplicate will be created. If your business operates across multiple Podium locations, run a pre-import deduplication pass using a shared phone-number index to decide which location a contact should be canonical at.
• Email-only, no phone: Podium will create the contact without duplicate detection (phone is the upsert key). Multiple imports of an email-only contact will create duplicate records. Deduplicate email-only contacts before loading.
• No match: A new contact is created and the response returns the new uid.

Your mapping table (local Missive Contact ID → Podium Contact UID) must handle all three outcomes and store the resolved Podium UID regardless of whether it came from a 201 Created or a 409 Conflict response.

Conversations and Messages

Missive Conversations → Podium Conversations. Missive conversations are channel-agnostic threads that can contain email, SMS, WhatsApp, and social messages in a single thread. Podium conversations are channel-specific and tied to a Location + Contact pair.

Podium provides a dedicated message import endpoint (POST /v4/messages/import) that imports historical messages without actually sending them to the recipient. This is the correct endpoint for migration — do not use the send message endpoint, which would deliver live messages to real phone numbers.

Podium conversation creation is implicit. There is no POST /v4/conversations endpoint that you call directly. A conversation is created automatically the first time you import (or send) a message for a given Location + Contact phone number pair. Subsequent messages to the same pair are appended to the existing conversation thread. This means your loading sequence must be: Contact creation → Message import (first message creates the conversation implicitly) → Additional message imports.

Timestamp ordering behavior: Podium sorts messages within a conversation by the createdAt field you supply on import, not by insertion order. If you import messages non-chronologically (e.g., paginating backwards through Missive history), Podium will re-sort them by createdAt and the thread will display in the correct chronological order. Verify this in a dry run against your specific Podium tenant — behavior may differ if createdAt is omitted or malformed.

Internal Missive comments must be filtered out entirely, or concatenated and injected as internal notes on the Podium contact profile. Do not inject internal Missive chats as standard messages in Podium — this risks exposing internal dialogue to customers if the thread is ever exported or mishandled by an automation.

Entities with No Podium Equivalent

These Missive features have no native target in Podium:

• Internal chat threads — Podium has basic internal notes but not threaded team chat within conversations.
• Tasks — Podium has no task management. Migrate to a separate tool or discard.
• Contact Books (as an organizational unit) — Podium uses Locations instead. Map each Contact Book to a Location or flatten.
• Rules and automations — Must be manually recreated in Podium's automation builder. No programmatic migration path.
• Shared mailbox structure — Podium's inbox is Location-scoped, not mailbox-scoped.

Entities Unique to Podium

Podium has features Missive doesn't, and they'll be empty post-migration:

• Reviews — Start fresh. Podium's review management is purpose-built.
• Payments/Invoices — Missive has no payment data to migrate.
• Webchat widget — Configure from scratch in Podium.
• Review invitations and campaigns — Build new in Podium.

Handling Channel Mismatches

The most jarring aspect of this migration is the UI constraint. Podium is built for text messages. Missive is heavily used for email.

The HTML to Plain Text Problem

When you extract an email message from Missive, the payload contains rich HTML. If you push raw HTML into Podium via the message import endpoint, Podium will either reject the payload or render raw HTML tags in the SMS UI, making the thread unreadable.

You must pass all Missive email bodies through an HTML-to-text parser before loading them into Podium. Expect formatting loss — tables, inline images, and styled text won't survive.

Truncation Strategies

Even stripped of HTML, a 1,500-word email is hostile to an SMS UI. Implement a truncation rule in your ETL pipeline:

1. Extract the first 300 characters of the Missive email body.
2. Append a tag like [Truncated Historical Email].
3. (Optional) Generate a PDF of the original Missive email and attach it to the Podium message using Podium's attachment endpoints.

This preserves the context for the agent without destroying the usability of the Podium inbox.

Multi-Channel Threading

Missive allows a single thread to start as an email, switch to SMS, and end in a WhatsApp message. Podium expects conversations to be channel-specific. When pushing a multi-channel Missive thread to Podium, you must either:

• Split the thread into separate Podium conversations (one per channel)
• Flatten everything into a single SMS-style text thread, labeling the original channel in the message body

Neither is perfect. Splitting preserves channel separation but fragments the conversation timeline. Flattening keeps the timeline intact but loses channel context. For most teams, flattening with channel labels is the more practical choice.

Missive Attachment URL Expiry

Missive stores attachments as signed, time-limited URLs. If your extraction phase and Podium upload phase span more than a few hours — which is likely for large datasets — those URLs will expire before you attempt to re-upload the files.

The correct approach:

1. During extraction, immediately download every attachment binary to local disk or an S3 staging bucket. Do not store only the URL.
2. Check the MIME type against Podium's allowed list (standard images: JPEG, PNG, GIF; documents: PDF; typically under 5MB per file).
3. Upload from your staging location to Podium's attachment endpoint during the load phase.

Any attachment not downloaded at extraction time is unrecoverable after URL expiry unless Missive support can regenerate the signed URL for your specific export.

Migration Approaches Compared

Option 1: CSV Export + Manual Import (Contacts Only)

When to use it: You only need contacts and can discard conversation history.

Missive does not offer a self-service contact export from the UI. You must either contact Missive support to request a CSV export or use the Missive API to extract contacts programmatically. Podium accepts contact creation via its API (POST /v4/contacts).

Pros: Simplest path for contacts. No code required if you request the CSV from Missive support. Cons: No conversation history. No message threading. No labels or assignments. Manual cleanup required for E.164 phone number formatting.

Option 2: Zapier/Make (Forward-Only, No History)

When to use it: You want new Missive conversations to create Podium contacts going forward during a transition period.

Missive has native Zapier triggers for new messages and new contacts. Podium has Zapier actions for creating contacts and sending messages. This works for real-time forwarding but cannot backfill historical data.

Pros: No engineering effort. Good for a transition period. Cons: Cannot migrate historical conversations. Zapier's execution limits make it impractical for anything beyond a trickle of new records.

Option 3: Custom API-Based ETL Pipeline (Full Migration)

When to use it: Any production migration requiring conversation history, threaded messages, contact integrity, and metadata preservation.

Extract from Missive's REST API → Transform the data model → Load into Podium's API. This is the only path that preserves conversation history with original timestamps via Podium's message import endpoint.

Pros: Full data fidelity. Historical timestamps preserved. Programmatic deduplication and validation. Resumable with checkpoint logic. Cons: Requires engineering effort (Python or Node.js, typically 3–7 days for a production-grade script). Must handle rate limits on both sides. Requires a Podium developer account (approval takes several days) and a Missive Productive plan for API access.

Step-by-Step: Custom ETL Migration

Step 1: Secure API Access on Both Platforms

Missive: Generate an API token from your Missive preferences under the API tab. You must be on the Productive plan ($24/user/month billed annually) or higher — API tokens are not available on the Starter or Free plans. All tokens are personal; there is no organization-level token.

Podium: Apply for a developer account at developer.podium.com. Approval typically takes 3–5 business days. Podium requires a business use case during signup; migrations are an accepted use case, but you should state this explicitly in the application to avoid rejection.

Once approved, create an OAuth 2.0 application. For a migration pipeline, you need the following OAuth scopes:

Complete the OAuth 2.0 authorization code flow to obtain an access_token and refresh_token scoped to the target Location(s). Store the refresh_token securely — the access_token will expire (typically in 1 hour) and must be refreshed continuously during multi-day import runs. The Client Secret cannot be retrieved after leaving the creation page; store it in a secrets manager immediately.

Step 2: Provision Locations and User Mappings

Do not attempt to map users and locations dynamically on the fly. Create a static mapping file in your pipeline configuration before extracting anything.

{
  "location_map": {
    "missive_contact_book_123": "podium_location_abc",
    "missive_contact_book_456": "podium_location_def"
  },
  "user_map": {
    "missive_user_789": "podium_user_ghi"
  }
}

Every API call in Podium v4 requires a location_id. If your Missive setup uses one generic support email for five physical storefronts, you must build logic to parse the Missive conversation context and assign it to the correct Podium location_id. If you cannot determine the location, route it to a default "HQ" location in Podium.

Provision all required Locations in Podium manually or via API. Ensure all agents have logged into Podium at least once to initialize their user records.

Step 3: Extract Data from Missive

Extract in this order: Contacts → Conversations → Messages. Attachments should be downloaded immediately during the messages phase — do not defer attachment downloads.

Contacts extraction:

import requests
import time
 
MISSIVE_TOKEN = "your_missive_api_token"
BASE_URL = "https://public.missiveapp.com/v1"
headers = {"Authorization": f"Bearer {MISSIVE_TOKEN}", "Content-Type": "application/json"}
 
def extract_contacts(contact_book_id):
    contacts = []
    offset = 0
    while True:
        resp = requests.get(
            f"{BASE_URL}/contacts",
            headers=headers,
            params={"contact_book_id": contact_book_id, "limit": 200, "offset": offset}
        )
        resp.raise_for_status()
        batch = resp.json().get("contacts", [])
        if not batch:
            break
        contacts.extend(batch)
        offset += len(batch)
        time.sleep(1)  # Respect rate limits
    return contacts

Conversations extraction:

Missive conversations paginate using an until cursor based on last_activity_at timestamps. The max page size is 50 conversations. Note that Missive's API may return more conversations than the limit value in a single page — your code must use len(batch) as the actual page size rather than assuming the limit parameter is an exact ceiling:

def extract_conversations():
    conversations = []
    until = None
    while True:
        params = {"limit": 50, "all": "true"}
        if until:
            params["until"] = until
        resp = requests.get(f"{BASE_URL}/conversations", headers=headers, params=params)
        resp.raise_for_status()
        batch = resp.json().get("conversations", [])
        if not batch:
            break
        conversations.extend(batch)
        # Use actual batch length, not the limit param — Missive may return
        # more items than requested. Cursor on the last item's timestamp.
        until = batch[-1]["last_activity_at"]
        time.sleep(1)
    return conversations

Messages extraction: Messages are fetched per-conversation and paginate at 10 per page. A conversation with 200 messages requires 20 API calls just for that thread.

def extract_messages(conversation_id):
    resp = requests.get(
        f"{BASE_URL}/conversations/{conversation_id}/messages",
        headers=headers
    )
    resp.raise_for_status()
    return resp.json().get("messages", [])

For 100,000 conversations, that's 100,000+ API calls just for message bodies. Implement exponential backoff in your extraction logic to handle 429 Too Many Requests responses.

Step 4: Transform the Data Model

This is the most engineering-intensive phase. Key transformations:

1. Location assignment. Every Podium contact and conversation needs a locationUid. Map each Missive team or Contact Book to a Podium Location using your static mapping file.

2. Phone number normalization. Podium requires E.164 format (+15551234567). Missive stores phone numbers in various formats. Use a library like phonenumbers (Python) to parse and normalize.

3. Contact deduplication. Run deduplication based on E.164 phone numbers and exact email matches before loading. Store the resulting Podium Contact UID in a local mapping table alongside the original Missive Contact ID — you'll need this for message loading. Your deduplication must handle the 409 Conflict response (see the Podium Contact Upsert Behavior section above).

4. Channel translation. Missive conversations can be multi-channel. Podium conversations are single-channel. Decide: split or flatten (see the Channel Mismatches section above).

5. Internal comments → discard or archive. Podium has no equivalent. Options: append as a final internal note on the Podium conversation, store in a custom attribute, or discard.

6. HTML stripping and truncation. Pass all email bodies through an HTML-to-text parser. Truncate long messages and tag them.

7. Labels → Tags. Pre-create all required tags in Podium before importing contacts. The Podium Contacts API allows setting tags during contact creation.

8. Attachment handling. Download files from Missive immediately during extraction (before signed URLs expire), check the MIME type against Podium's allowed list, and upload via Podium's attachment flow.

Step 5: Load into Podium

Create contacts:

import requests
 
PODIUM_TOKEN = "your_podium_oauth_token"
PODIUM_BASE = "https://api.podium.com/v4"
 
def create_or_resolve_podium_contact(contact_data, location_uid, id_map):
    """
    Returns the Podium contact UID, whether newly created or resolved from a 409.
    Stores the mapping from Missive ID to Podium UID in id_map.
    """
    payload = {
        "name": contact_data["name"],
        "phones": [{"number": contact_data["phone_e164"], "type": "mobile"}],
        "emails": [{"address": contact_data["email"]}] if contact_data.get("email") else [],
        "locationUid": location_uid,
        "tags": contact_data.get("tags", [])
    }
    resp = requests.post(
        f"{PODIUM_BASE}/contacts",
        headers={"Authorization": f"Bearer {PODIUM_TOKEN}", "Content-Type": "application/json"},
        json=payload
    )
    if resp.status_code == 201:
        podium_uid = resp.json()["uid"]
    elif resp.status_code == 409:
        # Contact already exists; extract UID from conflict response
        podium_uid = resp.json().get("existingUid") or resp.json()["uid"]
    else:
        resp.raise_for_status()
    id_map[contact_data["missive_id"]] = podium_uid
    return podium_uid

Refresh OAuth tokens during long-running imports:

def refresh_podium_token(client_id, client_secret, refresh_token):
    """
    Call before each batch to ensure the access token is valid.
    Podium access tokens typically expire after 3600 seconds (1 hour).
    """
    resp = requests.post(
        "https://api.podium.com/oauth/token",
        data={
            "grant_type": "refresh_token",
            "client_id": client_id,
            "client_secret": client_secret,
            "refresh_token": refresh_token
        }
    )
    resp.raise_for_status()
    tokens = resp.json()
    return tokens["access_token"], tokens.get("refresh_token", refresh_token)

Call refresh_podium_token at the start of each batch iteration during multi-day imports. Store the updated access_token and refresh_token to disk after each refresh — if the process crashes and restarts, you need valid tokens to resume without re-authorizing from scratch.

Import historical messages:

Use the message import endpoint — not the send message endpoint. The import endpoint writes message records to Podium without delivering them to the recipient's phone.

def import_message(location_uid, contact_phone, message_body, direction, timestamp):
    payload = {
        "locationUid": location_uid,
        "phoneNumber": contact_phone,  # E.164 format
        "body": message_body,
        "direction": direction,  # "inbound" or "outbound"
        "createdAt": timestamp  # ISO 8601; Podium sorts by this field
    }
    resp = requests.post(
        f"{PODIUM_BASE}/messages/import",
        headers={"Authorization": f"Bearer {PODIUM_TOKEN}", "Content-Type": "application/json"},
        json=payload
    )
    resp.raise_for_status()
    return resp.json()

Podium Import Endpoint Error Reference

Your pipeline must check the HTTP status code on every response. Silent failures (e.g., an unchecked 401 after token expiry) will halt imports without an error, making it appear the run completed successfully when it stopped partway through.

Step 6: Delta Sync and Cutover

Historical migrations take days to run. During this time, your team is still working in Missive, creating new data.

Once the historical load is complete, freeze your extraction timestamp. When you are ready to cut over:

1. Route your MX records, SMS numbers, and webchat widgets to Podium.
2. Run a delta sync script that extracts only Missive conversations updated after your freeze timestamp.
3. Load the delta into Podium.
4. Decommission Missive.

Step 7: Validate the Migration

Validation must cover three dimensions:

1. Count parity. Compare total contacts, conversations, and messages between source and target. Allow for a small delta from filtered records (email-only contacts, trashed conversations).

2. Spot-check sampling. A practical rule: 5% of migrated records, minimum 50, maximum 200, plus every known edge-case category. Verify:

   • Contacts with multiple phone numbers (does the primary match?)
   • Long conversation threads (>50 messages — verify pagination completeness)
   • Conversations with attachments (verify files are accessible)
   • Multi-channel Missive conversations (verify the splitting/flattening logic)
   • Contacts that returned a 409 during import (verify the resolved UID is the correct existing record)

3. Agent review. Have 2–3 team members search for known customers in Podium. Open recent conversations. Verify the message timeline reads correctly and assignments map to the right Podium users.

Rate Limit Management

Both APIs impose limits that directly constrain migration throughput.

Missive:

• 5 concurrent requests maximum
• 300 requests per minute
• 900 requests per 15-minute window
• Safe sustained rate: 1 request/second

Podium:

• ~10 requests/second for most endpoints (contacts, locations)
• ~10 requests/minute for message import (empirically observed; treat as a hard constraint)
• OAuth access token expiry (~3600 seconds) requires periodic refresh throughout long-running imports

Throughput calculation for a 25K conversation migration:

Assuming an average of 15 messages per conversation:

• Missive extraction: ~25K conversation list calls (500 pages × 50/page) + 25K message extraction calls (more for long threads) ≈ 30K–50K API calls. At 1 req/sec safe rate: 8–14 hours.
• Podium loading: 25K contact creates + 375K message imports. At ~10 req/sec for contacts and ~10 req/min for messages: contact load takes ~40 minutes; message import takes ~625 hours at 10/min.

For both sides, implement exponential backoff to handle 429 Too Many Requests responses. On the Podium side, your script must also handle automatic OAuth token refresh — a token expiry mid-batch that isn't caught will silently stop importing without an error unless you're checking every response code.

Common Edge Cases and Failure Modes

Email-only contacts. Missive is email-first; many contacts may lack phone numbers. Podium is SMS-first. Contacts without phones are technically importable but functionally inert. Decision: import and flag, or exclude and archive.

Missing phone numbers with social handles. If a Missive contact only has a Twitter handle, Podium will reject the creation payload. Your script must inject a placeholder email (e.g., twitter_handle_123@placeholder.local) to force creation, or drop the record entirely.

Rich HTML email content. Missive stores full HTML email bodies. Podium messages are plain text. HTML must be stripped or converted. Tables, inline images, and styled text won't survive the conversion.

Attachment handling and URL expiry. Missive stores attachments as signed, time-limited URLs. These URLs expire within hours. Download attachment binaries at extraction time — do not store only the URL and plan to re-download later.

Merged contacts in Missive. If agents merged two contacts in Missive, the API returns the primary contact ID but may retain historical message references to the secondary ID. Your extraction script must resolve all secondary IDs to the primary ID before mapping to Podium, or you will create orphaned conversations.

Guest conversations in Missive. Conversations where the API token user is a guest return only id and last_activity_at — no message content. You need an admin-level token or a user with full access to all shared mailboxes.

Podium developer account approval lag. Podium requires developer account approval before you can create OAuth applications. This takes 3–5 business days. State your migration use case explicitly in the application. Start this process before you begin any extraction work.

OAuth token refresh during multi-day imports. Podium OAuth access tokens expire (typically at 3600 seconds). For multi-day import jobs, your script must refresh the token automatically at the start of each batch and persist the updated tokens to disk. An uncaught token expiry mid-batch will silently stop importing with no error unless you're checking response codes.

Out-of-order message import. If your extraction produces messages in non-chronological order, supply accurate createdAt timestamps in ISO 8601 format. Podium sorts by createdAt, not by insertion order. Missing or malformed createdAt values will cause messages to appear in the wrong position in the conversation timeline.

409 Conflict on contact creation. A 409 does not mean failure — it means the contact already exists. Your pipeline must extract the existing uid from the 409 response body and continue using it. Treating 409 as an error will cause your pipeline to abort on any contact that was previously imported (e.g., during a dry run or a partial run).

Timeline and Effort Estimates

These estimates assume a single engineer building and running the ETL pipeline, including script development, testing, dry runs, production execution, and validation. Podium-side rate limits on message import are the dominant factor in elapsed time for medium and large datasets.

Pre-Migration Checklist

• Confirm Missive plan is Productive ($24/user/month) or higher for API access
• Generate Missive API token from preferences → API tab
• Verify token has admin-level access to all shared mailboxes (guest tokens return no message content)
• Apply for Podium developer account at developer.podium.com (allow 3–5 business days; state migration use case explicitly)
• Create Podium OAuth application; request scopes: contacts:read, contacts:write, messages:read, messages:write, locations:read
• Complete OAuth 2.0 authorization flow; securely store both access_token and refresh_token
• Inventory all Missive Contact Books, Labels, and Teams
• Map each Missive Team/Contact Book to a Podium Location
• Define the label → tag mapping table; pre-create all tags in Podium before loading
• Decide: what happens to email-only contacts? Import, skip, or flag?
• Decide: how to handle multi-channel conversations? Split or flatten?
• Decide: internal comments — archive as notes or discard?
• Build 409 Conflict handling into contact creation logic
• Build token refresh logic into the import batch loop; persist tokens to disk after each refresh
• Run a small dry-run (50–100 conversations) and validate output
• Build checkpoint/resume logic for multi-day import runs
• Verify attachment downloads happen at extraction time (not deferred)
• Schedule the production migration during low-traffic hours
• Plan a parallel-run period where both platforms are active

For a detailed pre-migration audit process, see our Missive Migration Checklist.

When Not to Migrate History

Sometimes the right call is to skip the historical data migration entirely:

• Your Missive history is primarily email. Podium is SMS-centric. Importing thousands of email conversations as plain-text message records creates noise, not value. Consider archiving Missive data and starting fresh in Podium.
• Your team is under 5 people. The engineering effort (80+ hours) may exceed the cost of re-entering key contacts manually and accepting a clean start.
• You're migrating to Podium for reviews and payments only. If the primary motivation is review management and text-to-pay — not conversation continuity — start clean. Import contacts via CSV/API and skip conversation history.

Making the Move

Missive to Podium is not a lift-and-shift. It's a data-model transformation between two platforms designed for different use cases. The contact migration is straightforward — until you hit the 409 upsert cases. The conversation migration is where complexity lives — multi-channel threading, HTML-to-plain-text conversion, rate limit constraints, the location assignment problem, expired attachment URLs, and OAuth token management across a multi-day load all require deliberate engineering decisions.

The Podium message import endpoint is your friend. Build your pipeline around it, add checkpoint logic for the multi-day load phase, handle 409 Conflicts as successful lookups rather than errors, refresh your OAuth token at the start of every batch, and validate aggressively before cutting over.

Building this ETL pipeline from scratch takes a senior engineer 80 to 200 hours depending on dataset size. You must handle cursor pagination, HTML stripping, rate limit backoffs, MIME type validation, OAuth token refresh, delta syncing, and upsert conflict resolution. If your engineering team is actively shipping product, pulling them off the roadmap to build a one-time migration script is rarely a good allocation of resources.