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Arguments

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key
str
required
The key to of the stream.
​
id
str | *
required
The stream entry ID. Supports multiple formats:
  • *: Fully automatic ID generation (both timestamp and sequence)
  • <ms>-<seq>: Explicit ID (e.g., “1526919030474-55”)
  • <ms>-*: Auto-generate sequence number for the given millisecond timestamp (Redis 8+)
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data
Dict[str, Any]
required
Key-value data to be appended to the stream.
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maxlen
int
The maximum number of entries to keep in the stream. Mutually exclusive with minid.
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approximate_trim
bool
default:"True"
Use approximate trimming (more efficient). When True, Redis may keep slightly more entries than specified. Defaults to True.
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nomkstream
bool
default:"False"
Prevent creating the stream if it does not exist. Defaults to False.
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minid
str
The minimum ID to keep. Entries with IDs lower than this will be removed. Mutually exclusive with maxlen.
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limit
int
Limit how many entries will be trimmed at most (only valid with approximate trimming).

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Response

The ID of the newly added entry.
redis.xadd("mystream", "*", {"name": "John Doe", "age": 30})

redis.xadd("mystream", "1634567890123-0", {"temperature": 25.5, "humidity": 60})

redis.xadd("mystream", "*", {"log_level": "error", "message": "Database connection failed"}, maxlen=100)

import time

# Specify millisecond timestamp, let Redis generate sequence number
ms = int(time.time() * 1000)
id1 = redis.xadd("mystream", f"{ms}-*", {"event": "login", "user": "john"})
print(id1)  # e.g., "1769347235123-0"

# Multiple entries with same ms but different sequence numbers
id2 = redis.xadd("mystream", f"{ms}-*", {"event": "logout", "user": "john"})
print(id2)  # e.g., "1769347235123-1"

# Use auto sequence for precise timestamp control
timestamp = 1634567890123
result = redis.xadd(
    "events",
    f"{timestamp}-*",
    {"type": "payment", "amount": 100.00, "currency": "USD"}
)
# Redis generates the sequence number automatically

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ID Format Details

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Automatic ID (*)

Fully automatic - Redis generates both the millisecond timestamp and sequence number.

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Explicit ID (<ms>-<seq>)

You provide both the millisecond timestamp and sequence number. Example: "1526919030474-55"

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Auto Sequence (<ms>-*) - Redis 8+

You provide the millisecond timestamp, Redis automatically generates the sequence number. This is useful when you need precise control over the timestamp but want Redis to handle sequence numbering. Benefits of Auto Sequence:
  • Precise timestamp control for time-sensitive data
  • Automatic sequence management prevents conflicts
  • Multiple entries can share the same millisecond with different sequences
  • Ideal for batch operations with consistent timestamps